WEBVTT 1 00:00:10.500 --> 00:00:14.199 A:middle L:90% So good morning and welcome to the Wireless of Virginia 2 00:00:14.199 --> 00:00:18.300 A:middle L:90% Tech seminar. It's been it's been a number of 3 00:00:18.300 --> 00:00:20.410 A:middle L:90% weeks since we've had a regular seminar. We've been 4 00:00:20.410 --> 00:00:23.679 A:middle L:90% having a number of faculty candidates come and visit and 5 00:00:23.679 --> 00:00:25.449 A:middle L:90% talk to us. We may be seminar it out, 6 00:00:25.449 --> 00:00:28.309 A:middle L:90% I don't know but thanks for coming this morning 7 00:00:28.320 --> 00:00:33.270 A:middle L:90% to hear Amir Zaghloul who's going to talk with 8 00:00:33.270 --> 00:00:37.500 A:middle L:90% us about metamaterials, meta surfaces and nanotechnology uh and 9 00:00:37.500 --> 00:00:41.780 A:middle L:90% their applications to antennas, sensors and cognitive radar, not 10 00:00:41.789 --> 00:00:46.689 A:middle L:90% cognitive radio. Apologies for that in the original announcement. 11 00:00:46.700 --> 00:00:49.729 A:middle L:90% Um so Amir has been with Virginia Tech with 12 00:00:49.729 --> 00:00:53.329 A:middle L:90% the ECE Department since 2001, which is 13 00:00:53.340 --> 00:00:56.079 A:middle L:90% uh which is a couple years longer than I have. 14 00:00:56.079 --> 00:00:57.600 A:middle L:90% He knocked on my door this morning and he 15 00:00:57.600 --> 00:00:59.359 A:middle L:90% thought I didn't know who he was but I did. 16 00:00:59.840 --> 00:01:03.180 A:middle L:90% Um so um he is currently a research professor 17 00:01:03.180 --> 00:01:06.670 A:middle L:90% with the ECE Department of Virginia Tech and is also with 18 00:01:06.680 --> 00:01:08.620 A:middle L:90% the U.S. Army Research Laboratory in Maryland. 19 00:01:08.629 --> 00:01:11.489 A:middle L:90% Uh prior to joining Virginia Tech in 2001, 20 00:01:11.489 --> 00:01:15.689 A:middle L:90% He was with Comsat Laboratories for 24 years, 21 00:01:15.700 --> 00:01:19.469 A:middle L:90% performing and directing research and development uh work on 22 00:01:19.469 --> 00:01:23.180 A:middle L:90% satellite communications and antennas. He's a life fellow of 23 00:01:23.180 --> 00:01:25.890 A:middle L:90% the IEEE, as well as a fellow 24 00:01:25.890 --> 00:01:30.299 A:middle L:90% of uh several other societies, the Applied Computational Electromagnetics Society, 25 00:01:30.299 --> 00:01:34.239 A:middle L:90% the American Institute of Aeronautics and Astronautics uh 26 00:01:34.250 --> 00:01:38.500 A:middle L:90% is also uh done a lot of service for the 27 00:01:38.500 --> 00:01:41.719 A:middle L:90% community in the form of organizing conferences and doing editorial 28 00:01:41.719 --> 00:01:44.439 A:middle L:90% work on journals and so on. So we're very 29 00:01:44.439 --> 00:01:46.599 A:middle L:90% happy to have Amir with us here in Blacksburg 30 00:01:46.599 --> 00:01:49.069 A:middle L:90% today. Although he's with Virginia tech, he's usually 31 00:01:49.069 --> 00:01:53.349 A:middle L:90% in northern Virginia. So thanks. Thank you. 32 00:01:55.739 --> 00:02:02.459 A:middle L:90% Thanks Alan for the introduction and for the opportunity. 33 00:02:05.640 --> 00:02:07.360 A:middle L:90% Okay. Or the opportunity to come and give a 34 00:02:07.360 --> 00:02:13.960 A:middle L:90% talk here in this series for wireless at Virginia Tech. 35 00:02:14.939 --> 00:02:19.520 A:middle L:90% Uh when I thought about what to talk about, 36 00:02:19.530 --> 00:02:22.250 A:middle L:90% I wanted actually two things to come out of 37 00:02:22.250 --> 00:02:25.719 A:middle L:90% this, I'd like to talk about the quote-unquote 38 00:02:25.729 --> 00:02:30.780 A:middle L:90% exciting work that's being done in the area of electromagnetics 39 00:02:30.780 --> 00:02:37.659 A:middle L:90% and antennas which lots of people or many people 40 00:02:37.659 --> 00:02:42.590 A:middle L:90% consider it to be an old technology that everything that 41 00:02:42.590 --> 00:02:45.240 A:middle L:90% was to be done was done already. I'd like 42 00:02:45.240 --> 00:02:46.919 A:middle L:90% to say that, no there are lots of exciting things 43 00:02:46.919 --> 00:02:51.960 A:middle L:90% going on and I'd like to mention that to you, 44 00:02:52.240 --> 00:02:58.259 A:middle L:90% especially to the young people who are probably interested 45 00:02:58.259 --> 00:03:01.340 A:middle L:90% in lots of other areas. The other thing I'd 46 00:03:01.340 --> 00:03:05.090 A:middle L:90% like to give you a little bit of introduction about 47 00:03:05.090 --> 00:03:08.289 A:middle L:90% the army research where I spend all my time these 48 00:03:08.289 --> 00:03:13.909 A:middle L:90% days as a member of one of the director 49 00:03:13.909 --> 00:03:19.159 A:middle L:90% they're called sensors and electronic devices. And I'm doing 50 00:03:19.159 --> 00:03:23.590 A:middle L:90% lots of research on antennas and on other related things 51 00:03:23.599 --> 00:03:29.379 A:middle L:90% that are focused on army needs. Uh thinking about 52 00:03:29.379 --> 00:03:32.030 A:middle L:90% like a good title to have here, I chose 53 00:03:32.030 --> 00:03:38.250 A:middle L:90% almost every buzzword that I can throw into the title. 54 00:03:38.639 --> 00:03:40.909 A:middle L:90% So I put meta materials, metal services, 55 00:03:40.909 --> 00:03:46.539 A:middle L:90% nanotechnology, cognitive radar. And if I miss anything 56 00:03:46.550 --> 00:03:49.469 A:middle L:90% let me know and I'm willing to throw it in 57 00:03:49.469 --> 00:03:53.159 A:middle L:90% as well. [Inaudible] Plasmonic comes under metamaterials as 58 00:03:53.159 --> 00:03:58.259 A:middle L:90% well, So, so we can we can have that 59 00:03:58.259 --> 00:04:00.270 A:middle L:90% cover. Although when I talk about metamaterials the 60 00:04:00.270 --> 00:04:10.400 A:middle L:90% only thing that I am uh I'm missing okay would 61 00:04:10.400 --> 00:04:15.229 A:middle L:90% be the the uh photonics area and areas in the 62 00:04:15.229 --> 00:04:17.949 A:middle L:90% frequency band that are beyond our rf and terahertz. 63 00:04:19.040 --> 00:04:24.370 A:middle L:90% Uh my talk is going to include this outline 64 00:04:24.379 --> 00:04:28.100 A:middle L:90% uh on how much time I have just to pace 65 00:04:28.100 --> 00:04:31.230 A:middle L:90% myself. I think we have reserved the room until 66 00:04:31.230 --> 00:04:35.959 A:middle L:90% 12:15. Okay. Okay I'll be done by then. 67 00:04:38.240 --> 00:04:41.379 A:middle L:90% Uh This is outline of the what I'm talking 68 00:04:41.379 --> 00:04:46.110 A:middle L:90% about the three main things meta materials with definition applications 69 00:04:46.110 --> 00:04:50.389 A:middle L:90% and stuff meta services on actually focusing on one type 70 00:04:50.389 --> 00:04:55.949 A:middle L:90% of metal surface which the electromagnetic band gap services. 71 00:04:56.279 --> 00:04:59.910 A:middle L:90% And then I'm going to talk about nanotechnology and also 72 00:04:59.910 --> 00:05:03.360 A:middle L:90% I'm focusing on the carbon nanotube part of the nanotechnology. 73 00:05:03.360 --> 00:05:06.699 A:middle L:90% We are doing work in other parts of nanotechnology 74 00:05:06.699 --> 00:05:11.040 A:middle L:90% using graphene and other things. But I'm talking mainly 75 00:05:11.040 --> 00:05:15.540 A:middle L:90% about the CNTS. So this is I 76 00:05:15.540 --> 00:05:16.850 A:middle L:90% hope to cover all of this in the next hour, 77 00:05:17.339 --> 00:05:21.029 A:middle L:90% but before we get there I'm going to have 78 00:05:21.029 --> 00:05:27.000 A:middle L:90% to go to a commercial break with word from our 79 00:05:27.000 --> 00:05:32.370 A:middle L:90% sponsor the army. Okay this is the ideal situation 80 00:05:32.379 --> 00:05:36.459 A:middle L:90% that we hope all of us hope to have in 81 00:05:36.459 --> 00:05:41.339 A:middle L:90% research work. I would like to have a combination 82 00:05:41.350 --> 00:05:48.259 A:middle L:90% of or collaboration between academia, defense labs and industry 83 00:05:48.740 --> 00:05:54.569 A:middle L:90% actually other kind of labs fall under industry but here 84 00:05:54.569 --> 00:05:58.509 A:middle L:90% we are separating Defense labs for the Army, Navy 85 00:05:58.509 --> 00:06:03.050 A:middle L:90% and Air Force and the like and the the combination 86 00:06:03.050 --> 00:06:06.389 A:middle L:90% of all these things here is what we call here 87 00:06:06.389 --> 00:06:13.819 A:middle L:90% transform transformative science and the main focus or the main 88 00:06:13.819 --> 00:06:16.170 A:middle L:90% things that we are trying to use in this three 89 00:06:16.170 --> 00:06:21.500 A:middle L:90% combination of course is the facilities which are plenty in 90 00:06:21.500 --> 00:06:26.459 A:middle L:90% all the three are in the three circles here people, 91 00:06:27.040 --> 00:06:30.829 A:middle L:90% smart people in all the three organizations and of 92 00:06:30.829 --> 00:06:34.959 A:middle L:90% course the resources that everyone has to has to offer 93 00:06:35.439 --> 00:06:40.870 A:middle L:90% uh and that will give us an efficient effective and 94 00:06:40.870 --> 00:06:45.009 A:middle L:90% agile resource system. Okay. In the area that 95 00:06:45.009 --> 00:06:48.550 A:middle L:90% we're talking about the antennas and electromagnetics and uh 96 00:06:48.560 --> 00:06:54.110 A:middle L:90% the other words that I mentioned uh I think uh 97 00:06:54.120 --> 00:07:00.430 A:middle L:90% it cannot be more helpful than this. Getting cooperation 98 00:07:00.430 --> 00:07:05.250 A:middle L:90% cooperation between these 3 circles here. one of 99 00:07:05.250 --> 00:07:09.759 A:middle L:90% the things in order to put that in more practice 100 00:07:10.240 --> 00:07:14.350 A:middle L:90% or more practical way at the Army research lab. 101 00:07:14.740 --> 00:07:18.949 A:middle L:90% Uh We came up with this idea. Um Of 102 00:07:18.949 --> 00:07:21.550 A:middle L:90% course I was not part of we here but like 103 00:07:21.550 --> 00:07:23.930 A:middle L:90% the A. R. L. Came up with 104 00:07:23.930 --> 00:07:28.819 A:middle L:90% this idea of opens campus in the past what we 105 00:07:28.819 --> 00:07:31.160 A:middle L:90% have been doing. We have been collaborating with academia 106 00:07:31.639 --> 00:07:38.110 A:middle L:90% and giving contracts doing work and watching the results and 107 00:07:38.120 --> 00:07:41.870 A:middle L:90% following everything that's being done there. But there was 108 00:07:41.879 --> 00:07:46.170 A:middle L:90% always the restriction of having people from academia come and 109 00:07:46.170 --> 00:07:50.350 A:middle L:90% spend some time at the research labs, there was 110 00:07:50.350 --> 00:07:54.850 A:middle L:90% lots of that but all of these things came with 111 00:07:54.850 --> 00:07:59.790 A:middle L:90% some restrictions. What is being done here will have 112 00:07:59.790 --> 00:08:03.850 A:middle L:90% an area called open campus within the facilities at A.R.L. 113 00:08:03.850 --> 00:08:05.470 A:middle L:90% Uh That is going to 114 00:08:05.470 --> 00:08:11.509 A:middle L:90% be dedicated to people coming from outside and spending the 115 00:08:11.509 --> 00:08:15.149 A:middle L:90% time there. And that is going to include it's 116 00:08:15.149 --> 00:08:18.009 A:middle L:90% not going to be limited for us citizens anymore, 117 00:08:18.019 --> 00:08:22.139 A:middle L:90% it's going to include foreign nationals which of course was 118 00:08:22.139 --> 00:08:26.079 A:middle L:90% not the case before. So smart people who would 119 00:08:26.079 --> 00:08:31.920 A:middle L:90% like to come and do work and whether being students 120 00:08:31.920 --> 00:08:35.620 A:middle L:90% or faculty they can come and spend some time and 121 00:08:35.629 --> 00:08:39.009 A:middle L:90% in that time they are going to collaborate with people 122 00:08:39.019 --> 00:08:41.809 A:middle L:90% at the army line. Of course that will be 123 00:08:41.809 --> 00:08:46.549 A:middle L:90% in a restricted area but you're going to have access 124 00:08:46.559 --> 00:08:50.480 A:middle L:90% to lots of the facilities that we have in terms 125 00:08:50.480 --> 00:08:54.759 A:middle L:90% of either computer stuff or lab area or something like 126 00:08:56.240 --> 00:09:00.240 A:middle L:90% like that. So it's a campus like environment that 127 00:09:00.240 --> 00:09:03.320 A:middle L:90% we're going to have there and you and it's going 128 00:09:03.320 --> 00:09:09.509 A:middle L:90% to be access to everybody and it's going to be 129 00:09:09.509 --> 00:09:13.549 A:middle L:90% an expansion of the collaboration that we already have. 130 00:09:15.440 --> 00:09:18.120 A:middle L:90% I don't know what I do to stop this thing 131 00:09:18.120 --> 00:09:24.809 A:middle L:90% from disappearing every females. Um This is of course 132 00:09:24.820 --> 00:09:28.009 A:middle L:90% people will have access to the facilities that we have 133 00:09:28.009 --> 00:09:35.759 A:middle L:90% which which I can say it's extremely uh We are 134 00:09:35.240 --> 00:09:39.100 A:middle L:90% we are extremely well equipped with lots of good facilities 135 00:09:39.350 --> 00:09:43.539 A:middle L:90% that we're using in our research. And the last 136 00:09:43.539 --> 00:09:46.000 A:middle L:90% item here is that it's energetic with Maryland and DC 137 00:09:46.000 --> 00:09:50.740 A:middle L:90% But also that includes Virginia. Uh 138 00:09:50.740 --> 00:09:56.149 A:middle L:90% huh. Uh area because of the closeness then uh 139 00:09:56.159 --> 00:09:58.929 A:middle L:90% there is some collaboration is going to be with local 140 00:09:58.929 --> 00:10:03.559 A:middle L:90% small business and things like that. So I encourage 141 00:10:03.559 --> 00:10:07.950 A:middle L:90% you to consider this as part of the research that 142 00:10:07.950 --> 00:10:11.100 A:middle L:90% you would like to do. And there's a website 143 00:10:11.110 --> 00:10:15.460 A:middle L:90% where you can actually apply to go to uh for 144 00:10:15.460 --> 00:10:18.470 A:middle L:90% internship in the summer. I don't have it with 145 00:10:18.470 --> 00:10:20.519 A:middle L:90% me now but if you email me I can send 146 00:10:20.519 --> 00:10:24.570 A:middle L:90% you all the information if you are interested in coming 147 00:10:24.570 --> 00:10:26.899 A:middle L:90% for the summer months to spend some time at the 148 00:10:26.899 --> 00:10:30.259 A:middle L:90% A. R. L. Again that's being a 149 00:10:30.269 --> 00:10:37.159 A:middle L:90% student or faculty. We both are wrong. Uh 150 00:10:37.840 --> 00:10:43.559 A:middle L:90% The lab itself this is just the organization very sort 151 00:10:43.559 --> 00:10:50.350 A:middle L:90% of high level organization chart here we have of course 152 00:10:50.350 --> 00:10:54.769 A:middle L:90% the director of the labs and the labs includes six 153 00:10:54.779 --> 00:11:01.100 A:middle L:90% directors vehicle technology human resource human research and engineering uh 154 00:11:01.110 --> 00:11:05.159 A:middle L:90% sort of of ability, lethal Itty analysis, competition 155 00:11:05.159 --> 00:11:09.139 A:middle L:90% and information sciences, sensors and electric devices. That's 156 00:11:09.139 --> 00:11:16.080 A:middle L:90% where I reside. Weapons and material research and lots 157 00:11:16.080 --> 00:11:20.250 A:middle L:90% of collaboration among the different directorates. Uh But the 158 00:11:20.250 --> 00:11:22.899 A:middle L:90% work that are is of interest to the wireless group 159 00:11:22.899 --> 00:11:33.409 A:middle L:90% here is going to fall in. Okay I guess 160 00:11:33.409 --> 00:11:35.059 A:middle L:90% I cannot point to this thing here. It's going 161 00:11:35.059 --> 00:11:41.629 A:middle L:90% to it falls into the The more to the three 162 00:11:41.629 --> 00:11:45.559 A:middle L:90% on the right here. The lots of work in 163 00:11:45.559 --> 00:11:50.799 A:middle L:90% wireless along with electro Magnetics and antennas radar and and 164 00:11:50.809 --> 00:11:54.269 A:middle L:90% things of that nature. And very important the work 165 00:11:54.269 --> 00:11:58.279 A:middle L:90% we are collaborating on with the materials people because when 166 00:11:58.279 --> 00:12:03.850 A:middle L:90% you see in my presentation we are doing more work 167 00:12:03.850 --> 00:12:09.679 A:middle L:90% with materials to improve the kind of devices and antennas 168 00:12:09.679 --> 00:12:13.559 A:middle L:90% that we produced for the army. The seventh member 169 00:12:13.559 --> 00:12:18.850 A:middle L:90% of this organization is the Army research Office. It 170 00:12:18.850 --> 00:12:20.850 A:middle L:90% operates under the A. R. L. And 171 00:12:20.850 --> 00:12:26.039 A:middle L:90% thats the one actually that catch the attention of academia 172 00:12:26.039 --> 00:12:28.690 A:middle L:90% because that's where the money is. You get the 173 00:12:28.690 --> 00:12:31.850 A:middle L:90% money from a roo a roo in contracts uh which 174 00:12:31.850 --> 00:12:35.710 A:middle L:90% is part of A. R. L. Uh 175 00:12:35.720 --> 00:12:39.889 A:middle L:90% sometimes we get to review some of the proposals that 176 00:12:39.889 --> 00:12:45.360 A:middle L:90% are submitted there but we are working in the other 177 00:12:45.539 --> 00:12:48.059 A:middle L:90% direct with and interact with the R. O. 178 00:12:48.340 --> 00:12:52.649 A:middle L:90% On some of these uh contractual issues here. A 179 00:12:52.649 --> 00:12:56.759 A:middle L:90% roo is situated in north Carolina as you may know 180 00:12:56.840 --> 00:13:01.580 A:middle L:90% . Okay so now we go back to the technical 181 00:13:01.580 --> 00:13:03.940 A:middle L:90% material here and I'm going to talk first about meta 182 00:13:03.940 --> 00:13:07.610 A:middle L:90% materials and for those of you who don't know the 183 00:13:07.610 --> 00:13:11.850 A:middle L:90% definition, what is meta materials. It is something 184 00:13:11.850 --> 00:13:16.840 A:middle L:90% that is not natural, it is material that is 185 00:13:16.970 --> 00:13:22.580 A:middle L:90% engineered. Okay. It doesn't doesn't happen in nature 186 00:13:22.590 --> 00:13:28.289 A:middle L:90% and it is not like the simple composite materials like 187 00:13:28.299 --> 00:13:31.149 A:middle L:90% when you have substrate for circuits and stuff. There 188 00:13:31.149 --> 00:13:33.649 A:middle L:90% is material there and the substrate but that is a 189 00:13:33.649 --> 00:13:37.629 A:middle L:90% simple composite material. The meta material includes more than 190 00:13:37.629 --> 00:13:43.259 A:middle L:90% that material and includes some insertions that will give the 191 00:13:43.259 --> 00:13:50.409 A:middle L:90% material properties that you cannot achieve in uh using any 192 00:13:50.409 --> 00:13:54.590 A:middle L:90% of the natural or simple composite materials. The war 193 00:13:54.590 --> 00:13:58.840 A:middle L:90% of the meta materials actually um is relatively recent. 194 00:13:58.850 --> 00:14:03.820 A:middle L:90% Uh It came about maybe a few decades back, 195 00:14:03.820 --> 00:14:07.509 A:middle L:90% two or three decades back. It was the word 196 00:14:07.519 --> 00:14:13.080 A:middle L:90% was coined by a professor at University of texas at 197 00:14:13.080 --> 00:14:22.409 A:middle L:90% Austin. Roger Roger Walser who coined the name metamaterials 198 00:14:22.549 --> 00:14:24.139 A:middle L:90% . And after that he opened his own company called 199 00:14:24.139 --> 00:14:31.529 A:middle L:90% metamaterials, inc but but but the word itself Includes 200 00:14:31.539 --> 00:14:35.070 A:middle L:90% lots of work that was done even before that. 201 00:14:35.269 --> 00:14:37.440 A:middle L:90% If you go back to the 60s or even before 202 00:14:37.440 --> 00:14:41.429 A:middle L:90% that you will find that the concept of producing material 203 00:14:41.429 --> 00:14:46.110 A:middle L:90% with certain characteristics was there But it was not named 204 00:14:46.110 --> 00:14:50.700 A:middle L:90% meta materials until recently. Generally speaking, if you 205 00:14:50.700 --> 00:14:56.580 A:middle L:90% look at the new absalon diagram that our quadrants that 206 00:14:56.580 --> 00:15:01.350 A:middle L:90% I have here the right hand uh top corner here 207 00:15:01.350 --> 00:15:11.960 A:middle L:90% positive, absolutely positive. Uh Is that something you 208 00:15:11.960 --> 00:15:18.710 A:middle L:90% can control? Or? 11. Okay. So 209 00:15:18.720 --> 00:15:24.590 A:middle L:90% uh okay, let me try to go faster than 210 00:15:24.590 --> 00:15:28.610 A:middle L:90% over the slide before it does. Uh The the 211 00:15:28.610 --> 00:15:31.950 A:middle L:90% right hand side is the right hand material which has 212 00:15:31.950 --> 00:15:35.629 A:middle L:90% positive, absolutely positive immune. And that's what we 213 00:15:35.629 --> 00:15:39.460 A:middle L:90% find in regular material. And in simple composite material 214 00:15:39.039 --> 00:15:41.470 A:middle L:90% . Uh If we go negative on any of these 215 00:15:41.470 --> 00:15:46.460 A:middle L:90% absolute arm, you we start generating these special meta 216 00:15:46.460 --> 00:15:50.580 A:middle L:90% materials uh and then we can use the negative part 217 00:15:50.580 --> 00:15:54.570 A:middle L:90% of absolute arm. You to give us certain characteristics 218 00:15:54.570 --> 00:15:56.759 A:middle L:90% in the material. Also on the right side, 219 00:15:56.769 --> 00:16:00.009 A:middle L:90% when we know that in free space. Absoluteal equal 220 00:16:00.009 --> 00:16:03.980 A:middle L:90% to one. Or relative productivity is equal to one 221 00:16:03.980 --> 00:16:07.649 A:middle L:90% and relative permeability is equal to one. If we 222 00:16:07.649 --> 00:16:11.070 A:middle L:90% exceed that, we go with mu of equal 10 223 00:16:11.070 --> 00:16:14.659 A:middle L:90% for instance, or absolute very, very high. 224 00:16:14.840 --> 00:16:17.830 A:middle L:90% Then we call that also math a materials and that's 225 00:16:17.830 --> 00:16:21.919 A:middle L:90% achieved by having certain inserts in the material. And 226 00:16:21.919 --> 00:16:25.649 A:middle L:90% that's going to give us some properties that we cannot 227 00:16:25.659 --> 00:16:29.320 A:middle L:90% achieve in the simple material. So meta material can 228 00:16:29.320 --> 00:16:30.809 A:middle L:90% fall in any of these. And this actually, 229 00:16:30.809 --> 00:16:34.580 A:middle L:90% by the way, the positive, the real part 230 00:16:34.580 --> 00:16:37.230 A:middle L:90% of absolute. And and then you of course we 231 00:16:37.230 --> 00:16:41.399 A:middle L:90% know absolute mu it's a complex number. So, 232 00:16:41.399 --> 00:16:44.690 A:middle L:90% but but what we have here is the is the 233 00:16:44.700 --> 00:16:47.919 A:middle L:90% real part. So this is the definition of the 234 00:16:47.919 --> 00:16:52.720 A:middle L:90% meta material. And um they we use them as 235 00:16:52.730 --> 00:16:57.179 A:middle L:90% just a simple tool set to redesign and tends to 236 00:16:57.179 --> 00:17:00.419 A:middle L:90% make them smaller to make them high efficiency to make 237 00:17:00.419 --> 00:17:06.450 A:middle L:90% them with higher gain and and all the other problems 238 00:17:06.450 --> 00:17:10.289 A:middle L:90% that we want to have in them. Uh Also 239 00:17:10.289 --> 00:17:15.069 A:middle L:90% to create some services that will give us certain properties 240 00:17:15.079 --> 00:17:18.990 A:middle L:90% in reflection because we know that the simple material that 241 00:17:18.990 --> 00:17:22.450 A:middle L:90% we have for reflection purposes is the simple ground plane 242 00:17:22.460 --> 00:17:26.470 A:middle L:90% uh where you have, if you have an object 243 00:17:26.470 --> 00:17:29.319 A:middle L:90% on the top of it, you create an image 244 00:17:29.329 --> 00:17:32.849 A:middle L:90% and then in order to get a positive response from 245 00:17:32.859 --> 00:17:34.529 A:middle L:90% the reflecting surface, you have to have your antenna 246 00:17:34.529 --> 00:17:38.259 A:middle L:90% for instance, a quarter wavelength above the ground plane 247 00:17:38.640 --> 00:17:42.490 A:middle L:90% . Uh When you use certain types of meta materials 248 00:17:42.490 --> 00:17:47.380 A:middle L:90% or methods services will find that we don't have to 249 00:17:47.380 --> 00:17:49.119 A:middle L:90% be that high above the ground plane. So we 250 00:17:49.119 --> 00:17:52.579 A:middle L:90% can actually reduce the profile of the antenna or the 251 00:17:52.579 --> 00:17:56.269 A:middle L:90% structure that we are doing. Also, we can 252 00:17:56.269 --> 00:18:00.480 A:middle L:90% use the properties of the metal material to give us 253 00:18:00.480 --> 00:18:03.619 A:middle L:90% impedance matching of the structure that we are building or 254 00:18:03.619 --> 00:18:07.269 A:middle L:90% the antenna we are building. And that again goes 255 00:18:07.269 --> 00:18:11.230 A:middle L:90% a long way in uh in improving the bandwidth, 256 00:18:11.230 --> 00:18:15.309 A:middle L:90% increasing the bandwidth, reducing the sauce uh of the 257 00:18:15.309 --> 00:18:18.349 A:middle L:90% antenna. We also use it to give us better 258 00:18:18.349 --> 00:18:22.170 A:middle L:90% mutual coupling, reduce mutual coupling between elements and antennas 259 00:18:22.170 --> 00:18:27.720 A:middle L:90% or electromagnetic structure. So those were some of the 260 00:18:27.720 --> 00:18:33.500 A:middle L:90% design criteria that we can get out of the metamaterials 261 00:18:33.940 --> 00:18:37.069 A:middle L:90% . These are some of the the meta material types 262 00:18:37.069 --> 00:18:41.289 A:middle L:90% that were published but there are hundreds more than these 263 00:18:41.289 --> 00:18:45.319 A:middle L:90% ones. The simple or the one of the basic 264 00:18:45.319 --> 00:18:49.460 A:middle L:90% ones. The one on the top left. Um 265 00:18:52.940 --> 00:18:56.019 A:middle L:90% What we have there is um uh if you look 266 00:18:56.019 --> 00:19:00.559 A:middle L:90% at the small print on on these sheets, we 267 00:19:00.559 --> 00:19:06.359 A:middle L:90% call that split ring resonator, which is actually um 268 00:19:07.240 --> 00:19:11.039 A:middle L:90% There's my point here, I guess is uh the 269 00:19:11.049 --> 00:19:14.730 A:middle L:90% in the small circles around this center block, the 270 00:19:14.730 --> 00:19:17.779 A:middle L:90% one to the left and the bottom. This called 271 00:19:17.779 --> 00:19:22.200 A:middle L:90% split ring resonator. Split ring resonator uh where you 272 00:19:22.200 --> 00:19:25.650 A:middle L:90% have the ring resonates at a certain frequency and you 273 00:19:25.650 --> 00:19:29.670 A:middle L:90% control the resonance by the dimensions and by the gap 274 00:19:29.940 --> 00:19:33.779 A:middle L:90% okay between the sides of the of the ring and 275 00:19:33.779 --> 00:19:37.119 A:middle L:90% there are different other different kinds and equivalent circuit of 276 00:19:37.119 --> 00:19:41.380 A:middle L:90% that thing represented in these small circles. The one 277 00:19:41.380 --> 00:19:45.740 A:middle L:90% to the top left again. Okay, gives us 278 00:19:45.750 --> 00:19:49.680 A:middle L:90% the split ring resonator gives us negative are not negative 279 00:19:49.680 --> 00:19:55.609 A:middle L:90% , but it controls the immune of the material and 280 00:19:55.609 --> 00:19:57.359 A:middle L:90% you can get negative mule with certain dimensions of it 281 00:19:57.740 --> 00:20:03.119 A:middle L:90% . However, it may be a narrow band behind 282 00:20:03.119 --> 00:20:06.099 A:middle L:90% the split ring and you can see it in the 283 00:20:06.109 --> 00:20:08.359 A:middle L:90% picture underneath it. There is a simple poles in 284 00:20:08.359 --> 00:20:12.319 A:middle L:90% front of the rings and those give us the negative 285 00:20:12.329 --> 00:20:15.369 A:middle L:90% absolute. So we can get negative, absolute and 286 00:20:15.369 --> 00:20:18.559 A:middle L:90% negative mu out of these things and the negative absolute 287 00:20:18.559 --> 00:20:23.690 A:middle L:90% concept actually came about back in 1963. Even before 288 00:20:23.690 --> 00:20:29.509 A:middle L:90% we talked about any matter materials were uh walter. 289 00:20:29.519 --> 00:20:34.369 A:middle L:90% Uh Rodman Wall Trotman. He actually introduced that back 290 00:20:34.369 --> 00:20:38.680 A:middle L:90% in 1963. Rodman is well is more known with 291 00:20:38.690 --> 00:20:41.349 A:middle L:90% for his Rotman lens, which we'll talk about in 292 00:20:41.349 --> 00:20:45.220 A:middle L:90% a few minutes and these are other types. And 293 00:20:45.220 --> 00:20:48.349 A:middle L:90% the one that's actually interesting if you look at the 294 00:20:48.349 --> 00:20:53.759 A:middle L:90% bottom here, you have something that is surrounding another 295 00:20:53.759 --> 00:21:00.390 A:middle L:90% object and its surrounding it to give it the property 296 00:21:00.569 --> 00:21:04.819 A:middle L:90% of cloaking. So if you have electromagnetic field coming 297 00:21:04.819 --> 00:21:08.049 A:middle L:90% hitting the object in the middle, as you can 298 00:21:08.049 --> 00:21:11.410 A:middle L:90% see in. Okay, let me do this. 299 00:21:11.420 --> 00:21:15.130 A:middle L:90% Okay. Uh If uh if you have the object 300 00:21:15.130 --> 00:21:21.559 A:middle L:90% surrounded by some material as you see here. Okay 301 00:21:21.569 --> 00:21:23.490 A:middle L:90% , this material which made out which is made out 302 00:21:23.490 --> 00:21:26.559 A:middle L:90% of metal material. Okay, It's going to cause 303 00:21:26.559 --> 00:21:30.450 A:middle L:90% the electric field when it comes to hit that object 304 00:21:30.839 --> 00:21:33.789 A:middle L:90% to go through the object ends to the surrounding material 305 00:21:33.920 --> 00:21:37.950 A:middle L:90% and come out as if there was nothing there. 306 00:21:37.099 --> 00:21:42.000 A:middle L:90% So it's doing what we call clocking of the object 307 00:21:42.009 --> 00:21:45.660 A:middle L:90% and and hiding it so that you don't see it 308 00:21:45.670 --> 00:21:48.089 A:middle L:90% with the with the electromagnetic wave, of course, 309 00:21:48.089 --> 00:21:52.339 A:middle L:90% the size of the cloaking material is much more than 310 00:21:52.339 --> 00:21:55.819 A:middle L:90% the size of the material that you'd like to hide 311 00:21:55.829 --> 00:21:57.730 A:middle L:90% . But of course the signal goes through and it 312 00:21:57.730 --> 00:22:11.190 A:middle L:90% doesn't see neither of them. Ah Okay. Along 313 00:22:11.190 --> 00:22:14.109 A:middle L:90% with the meta material, okay. Which has to 314 00:22:14.109 --> 00:22:18.460 A:middle L:90% use a large number of inserts periodic or random or 315 00:22:18.460 --> 00:22:25.029 A:middle L:90% whatever coordination. Uh We we wanted to be uh 316 00:22:25.039 --> 00:22:27.259 A:middle L:90% you can produce meta material, antennas made out of 317 00:22:27.259 --> 00:22:32.880 A:middle L:90% those things here. But after a while we came 318 00:22:32.890 --> 00:22:37.710 A:middle L:90% to think that not everything we build is actually meta 319 00:22:37.710 --> 00:22:41.250 A:middle L:90% material. In terms of being an antenna made of 320 00:22:41.250 --> 00:22:47.190 A:middle L:90% metal material. Someone from Arizona Oregon. Szarkowski came 321 00:22:47.190 --> 00:22:51.349 A:middle L:90% up with the expression that's called meta material inspired. 322 00:22:51.740 --> 00:22:55.369 A:middle L:90% That means it is something some kind of antenna. 323 00:22:55.380 --> 00:22:56.839 A:middle L:90% It's not, you cannot call it meta material, 324 00:22:56.839 --> 00:23:00.619 A:middle L:90% but it uses some of the properties that we develop 325 00:23:00.619 --> 00:23:03.609 A:middle L:90% in the meta material. So you can use single 326 00:23:03.609 --> 00:23:07.930 A:middle L:90% cell. You can using you can use some other 327 00:23:07.000 --> 00:23:11.769 A:middle L:90% metallic inclusions in order to use some antenna that does 328 00:23:11.769 --> 00:23:18.569 A:middle L:90% not necessarily have a medium that has certain absolute and 329 00:23:18.579 --> 00:23:22.259 A:middle L:90% new properties as in the meta material. So these 330 00:23:22.259 --> 00:23:26.069 A:middle L:90% are the sorts of definitions of these things here at 331 00:23:26.079 --> 00:23:29.589 A:middle L:90% A. R. L. Or at the D 332 00:23:29.589 --> 00:23:32.109 A:middle L:90% . O. D. In general. Uh We 333 00:23:32.109 --> 00:23:37.019 A:middle L:90% have our people have been working on different aspects of 334 00:23:37.019 --> 00:23:41.069 A:middle L:90% meta materials as you can see here back down to 335 00:23:41.079 --> 00:23:48.670 A:middle L:90% 1967 all the way to today and uh and uh 336 00:23:48.339 --> 00:23:52.819 A:middle L:90% oh oh this I'm sorry. Well that's a good 337 00:23:52.819 --> 00:23:56.640 A:middle L:90% idea. Okay. Uh So there's some work that 338 00:23:56.640 --> 00:24:00.369 A:middle L:90% was done outside era, like this piece here was 339 00:24:00.369 --> 00:24:04.380 A:middle L:90% done by University of michigan. Uh There is uh 340 00:24:04.390 --> 00:24:08.059 A:middle L:90% there is some other work that was done by by 341 00:24:08.059 --> 00:24:15.789 A:middle L:90% other companies uh around here. Um This actually is 342 00:24:15.799 --> 00:24:17.900 A:middle L:90% is my work is that I'm going to talk about 343 00:24:17.900 --> 00:24:21.809 A:middle L:90% in a few minutes who are we demonstrated the negative 344 00:24:21.809 --> 00:24:26.759 A:middle L:90% refractive index, both in simulation and in measurements. 345 00:24:26.140 --> 00:24:30.299 A:middle L:90% And then after that we started building some other material 346 00:24:30.299 --> 00:24:36.289 A:middle L:90% that has either negative absolute negative mu or high value 347 00:24:36.289 --> 00:24:38.200 A:middle L:90% of mu. That is going to give us also 348 00:24:38.200 --> 00:24:42.630 A:middle L:90% the reflection that we needed that will produce high gain 349 00:24:42.640 --> 00:24:47.509 A:middle L:90% out of the out of the antenna. So this 350 00:24:47.509 --> 00:24:52.789 A:middle L:90% is these are some examples here examples here of this 351 00:24:52.980 --> 00:24:56.660 A:middle L:90% . This one here is a high new material that 352 00:24:56.660 --> 00:24:59.359 A:middle L:90% we call it metaphor. Right? Again, this 353 00:24:59.740 --> 00:25:03.269 A:middle L:90% a concept that lots of people working on including meta 354 00:25:03.269 --> 00:25:07.329 A:middle L:90% material inc uh the meta materials inc the one that 355 00:25:07.339 --> 00:25:11.670 A:middle L:90% uh walls or roger walls or is is running out 356 00:25:11.670 --> 00:25:17.089 A:middle L:90% of texas. Uh This is also the same example 357 00:25:17.099 --> 00:25:19.599 A:middle L:90% . We have a metaphor, right material that is 358 00:25:19.609 --> 00:25:27.250 A:middle L:90% putting underneath this uh this printed antenna uh to improve 359 00:25:27.259 --> 00:25:30.200 A:middle L:90% the performance of it, give it high gain and 360 00:25:30.200 --> 00:25:37.140 A:middle L:90% uh and high efficiency are high uh basically high again 361 00:25:37.140 --> 00:25:40.930 A:middle L:90% with very small, very low profile. So the 362 00:25:40.930 --> 00:25:44.930 A:middle L:90% debt here is very small of the material under the 363 00:25:44.940 --> 00:25:48.559 A:middle L:90% antenna. Uh Then we started thinking about why we 364 00:25:48.559 --> 00:25:52.009 A:middle L:90% have to limit ourselves to the periodic materials. What 365 00:25:52.009 --> 00:25:56.559 A:middle L:90% happens if we go to random materials and that's what 366 00:25:56.559 --> 00:25:59.579 A:middle L:90% we have in this picture. We built a material 367 00:25:59.579 --> 00:26:03.349 A:middle L:90% that's made out of unit selves that are not arranged 368 00:26:03.539 --> 00:26:07.569 A:middle L:90% in a periodic structure but in random. And what 369 00:26:07.569 --> 00:26:10.160 A:middle L:90% we are going to get out of that is uh 370 00:26:10.170 --> 00:26:12.589 A:middle L:90% still we are working on that and uh we'll have 371 00:26:12.589 --> 00:26:17.009 A:middle L:90% some results on that. Uh We had some results 372 00:26:17.009 --> 00:26:21.809 A:middle L:90% but we'll have more results in the next hopefully short 373 00:26:21.809 --> 00:26:25.289 A:middle L:90% time. Actually, there's a master's thesis that will 374 00:26:25.289 --> 00:26:29.210 A:middle L:90% conclude end of this semester by one of the students 375 00:26:29.210 --> 00:26:32.380 A:middle L:90% , john Hodge, who's going to talk about some 376 00:26:32.380 --> 00:26:34.150 A:middle L:90% of these simulations that he did and that will be 377 00:26:34.150 --> 00:26:37.920 A:middle L:90% followed by uh We are planning on doing some other 378 00:26:37.920 --> 00:26:42.400 A:middle L:90% work on the analysis of that material. Regulars analysis 379 00:26:42.410 --> 00:26:45.220 A:middle L:90% from the E. M. Point of view and 380 00:26:45.230 --> 00:26:53.369 A:middle L:90% uh some uh uh more interesting simulation. Uh Okay 381 00:26:53.369 --> 00:26:56.750 A:middle L:90% , so, so we are proceeding in this line 382 00:26:56.750 --> 00:26:59.170 A:middle L:90% here to do lots of things. One thing we 383 00:26:59.170 --> 00:27:03.089 A:middle L:90% are doing by the way in designing the antennas, 384 00:27:03.099 --> 00:27:06.410 A:middle L:90% weather for meta materials or for others is that we 385 00:27:06.410 --> 00:27:10.450 A:middle L:90% have to design the antennas institute. That means in 386 00:27:10.450 --> 00:27:15.079 A:middle L:90% the presence of the environment that's going to be used 387 00:27:15.079 --> 00:27:18.809 A:middle L:90% at for instance, if you have an antenna design 388 00:27:18.819 --> 00:27:22.059 A:middle L:90% for use on a vehicle, then we have to 389 00:27:22.059 --> 00:27:26.549 A:middle L:90% design the antenna with the vehicle body behind the antenna 390 00:27:26.559 --> 00:27:29.049 A:middle L:90% to know exactly how the antenna is going to behave 391 00:27:29.740 --> 00:27:33.059 A:middle L:90% . Okay, so that's the institute sort of analysis 392 00:27:33.069 --> 00:27:37.890 A:middle L:90% is essential part of what we're doing for either analysis 393 00:27:37.890 --> 00:27:41.019 A:middle L:90% of this or any other intent. Other things we 394 00:27:41.019 --> 00:27:44.670 A:middle L:90% are doing is uh stack E B G. And 395 00:27:44.670 --> 00:27:47.759 A:middle L:90% I'm going to talk about that in a minute and 396 00:27:48.140 --> 00:27:53.220 A:middle L:90% and other things that uh we are doing within the 397 00:27:53.220 --> 00:27:57.380 A:middle L:90% army lab of course some of that is again with 398 00:27:57.390 --> 00:28:03.420 A:middle L:90% collaboration with other with universities and stuff. One example 399 00:28:03.420 --> 00:28:07.769 A:middle L:90% here is a multi layer metal material and we are 400 00:28:07.769 --> 00:28:11.220 A:middle L:90% starting from the individual cell and we are trying to 401 00:28:11.220 --> 00:28:17.730 A:middle L:90% find what is the macro uh performance of a block 402 00:28:17.730 --> 00:28:21.230 A:middle L:90% of metal material in analytical way. Of course we 403 00:28:21.230 --> 00:28:23.440 A:middle L:90% can do simulation but the simulation takes lots of time 404 00:28:23.440 --> 00:28:26.509 A:middle L:90% as we know. So we try to do some 405 00:28:26.509 --> 00:28:30.009 A:middle L:90% analytical, develop analytical tools for that. And this 406 00:28:30.009 --> 00:28:33.450 A:middle L:90% is being done by the University of Sienna in Italy 407 00:28:34.640 --> 00:28:38.349 A:middle L:90% . And this again is the metaphor right thing. 408 00:28:38.349 --> 00:28:41.049 A:middle L:90% These two here here we have an E. B 409 00:28:41.049 --> 00:28:47.559 A:middle L:90% . G. With multiple dimensions to give us broadband 410 00:28:47.569 --> 00:28:49.329 A:middle L:90% in addition to the stacked one that I showed you 411 00:28:49.329 --> 00:28:55.230 A:middle L:90% in previous view graph this work here is actually we 412 00:28:55.230 --> 00:28:59.309 A:middle L:90% have a PhD some deep already who's going to finish 413 00:28:59.309 --> 00:29:03.509 A:middle L:90% hopefully by the end of this year. Uh And 414 00:29:03.509 --> 00:29:08.609 A:middle L:90% his dissertation is mainly on the wideband electromagnetic band gap 415 00:29:08.609 --> 00:29:12.259 A:middle L:90% structure which is considered to be some kind of metal 416 00:29:12.259 --> 00:29:18.259 A:middle L:90% services. Uh So this again are the activities uh 417 00:29:18.269 --> 00:29:21.569 A:middle L:90% the objective the accomplishments and the approaches we take to 418 00:29:21.569 --> 00:29:25.490 A:middle L:90% analyze meta materials and build them and test them at 419 00:29:25.490 --> 00:29:29.690 A:middle L:90% the army line. Uh This is something that we 420 00:29:29.690 --> 00:29:33.029 A:middle L:90% did earlier. This is the one that I showed 421 00:29:33.029 --> 00:29:37.460 A:middle L:90% you in that uh timeline where we used a an 422 00:29:37.470 --> 00:29:42.170 A:middle L:90% element sell uh we call it capacitive lee loop uh 423 00:29:42.180 --> 00:29:45.160 A:middle L:90% loaded loop. Okay. Which is this one which 424 00:29:45.160 --> 00:29:49.440 A:middle L:90% is a little different than this littering resonator. Okay 425 00:29:49.440 --> 00:29:52.970 A:middle L:90% . But if you put again probe in front of 426 00:29:52.970 --> 00:29:56.589 A:middle L:90% it then this will give you the negative mule and 427 00:29:56.589 --> 00:29:59.640 A:middle L:90% this one will give you the negative absalon. And 428 00:29:59.640 --> 00:30:03.519 A:middle L:90% the combined structure is going to give you the negative 429 00:30:03.519 --> 00:30:07.309 A:middle L:90% refractive index. Okay. And we proved that and 430 00:30:07.309 --> 00:30:12.220 A:middle L:90% again this work also was a master's thesis topic that 431 00:30:12.220 --> 00:30:22.460 A:middle L:90% was done a few years ago um uh by wang 432 00:30:22.940 --> 00:30:27.369 A:middle L:90% that he did the simulation work and we did some 433 00:30:27.369 --> 00:30:33.400 A:middle L:90% of the experimental work at the RL the experiment's simple 434 00:30:33.400 --> 00:30:37.140 A:middle L:90% experiment experiment that we try to do to prove the 435 00:30:37.140 --> 00:30:41.130 A:middle L:90% refractive index of the negative refractive index was simply like 436 00:30:41.130 --> 00:30:44.069 A:middle L:90% this. We have a source and we have three 437 00:30:44.069 --> 00:30:47.779 A:middle L:90% receivers on a circle centered here. If we don't 438 00:30:47.779 --> 00:30:51.930 A:middle L:90% have material than the level of signal that we receive 439 00:30:51.930 --> 00:30:53.589 A:middle L:90% here. Out of this mono paul is going to 440 00:30:53.589 --> 00:30:56.970 A:middle L:90% be the same. Okay if we have a negative 441 00:30:56.970 --> 00:31:00.470 A:middle L:90% refractive index then the signal is going to come hit 442 00:31:00.480 --> 00:31:04.930 A:middle L:90% this medium, the negative refractive index medium and it's 443 00:31:04.930 --> 00:31:08.500 A:middle L:90% going to bend this way as you can see here 444 00:31:08.509 --> 00:31:12.089 A:middle L:90% Instead if this was positive material, it would refract 445 00:31:12.089 --> 00:31:17.960 A:middle L:90% this way and again the facts again and then you 446 00:31:17.960 --> 00:31:19.859 A:middle L:90% get reception somewhere here. But if you have the 447 00:31:19.859 --> 00:31:23.769 A:middle L:90% negative are negative refractive index then it's going to bend 448 00:31:23.769 --> 00:31:26.940 A:middle L:90% like this bend again as it gets out of the 449 00:31:26.940 --> 00:31:32.349 A:middle L:90% medium and you can have higher level here okay than 450 00:31:32.349 --> 00:31:34.500 A:middle L:90% what you get at these two points. So detecting 451 00:31:34.509 --> 00:31:37.690 A:middle L:90% much higher level here than these two points is an 452 00:31:37.690 --> 00:31:41.670 A:middle L:90% indication that we have a negative And in this material 453 00:31:42.039 --> 00:31:45.799 A:middle L:90% this concept is called the Perfect lines and that was 454 00:31:45.799 --> 00:31:48.710 A:middle L:90% introduced some time back. But what we did here 455 00:31:48.720 --> 00:31:52.569 A:middle L:90% , we realize it and we proved that we can 456 00:31:52.569 --> 00:31:55.410 A:middle L:90% actually do the measurements, the unit cell is like 457 00:31:55.410 --> 00:31:57.740 A:middle L:90% this. It's a simple loop like this printed on 458 00:31:57.740 --> 00:32:00.450 A:middle L:90% a piece of dielectric and on the other side of 459 00:32:00.450 --> 00:32:05.059 A:middle L:90% the electric we have a poll or problem like this 460 00:32:05.339 --> 00:32:08.559 A:middle L:90% to give us the negative negative. Also these dimensions 461 00:32:08.559 --> 00:32:13.089 A:middle L:90% are for certain frequency. You adjust the dimensions to 462 00:32:13.089 --> 00:32:14.809 A:middle L:90% get the frequency you want. But it's very, 463 00:32:14.819 --> 00:32:19.589 A:middle L:90% very much as scalable to different frequencies. And this 464 00:32:19.589 --> 00:32:21.670 A:middle L:90% is the set up. These are the pieces that 465 00:32:21.670 --> 00:32:25.220 A:middle L:90% we built and this is the result with the materials 466 00:32:25.230 --> 00:32:30.630 A:middle L:90% . The the signal from the source to the center 467 00:32:30.640 --> 00:32:36.480 A:middle L:90% receiver is like this but to the edge receiver is 468 00:32:36.480 --> 00:32:39.029 A:middle L:90% much lower. It's about maybe 10 or 15 db 469 00:32:39.029 --> 00:32:43.390 A:middle L:90% lower because of the focusing that you get in this 470 00:32:43.390 --> 00:32:46.819 A:middle L:90% direction here. Without the material, the to the 471 00:32:46.819 --> 00:32:50.170 A:middle L:90% center and the edge are very close to each other 472 00:32:50.640 --> 00:32:53.049 A:middle L:90% . The blue here is the s. shows a 473 00:32:53.059 --> 00:32:57.180 A:middle L:90% good match in in either case. So that shows 474 00:32:57.180 --> 00:33:00.849 A:middle L:90% the refractive index being negative and you have the focusing 475 00:33:00.859 --> 00:33:04.339 A:middle L:90% as a result of this reflective index. These are 476 00:33:04.339 --> 00:33:07.269 A:middle L:90% the measure data that that we did that show the 477 00:33:07.269 --> 00:33:09.559 A:middle L:90% same thing as I showed you in the simulation results 478 00:33:09.940 --> 00:33:13.190 A:middle L:90% . The next thing we did, we said that 479 00:33:13.200 --> 00:33:15.509 A:middle L:90% we are not going to do that only in one 480 00:33:15.509 --> 00:33:17.549 A:middle L:90% direction will do that in two directions. As you 481 00:33:17.549 --> 00:33:22.230 A:middle L:90% see here. This is one direction and the the 482 00:33:22.240 --> 00:33:24.289 A:middle L:90% orthogonal direction. The reason for that is that we 483 00:33:24.289 --> 00:33:29.660 A:middle L:90% wanted the material to be icy trap to have the 484 00:33:29.660 --> 00:33:35.440 A:middle L:90% negative performance negative refractive index uh with our psychotropic behavior 485 00:33:35.450 --> 00:33:38.250 A:middle L:90% uh in in all directions. So we did that 486 00:33:38.259 --> 00:33:42.410 A:middle L:90% and instead of one or the other directions which is 487 00:33:42.410 --> 00:33:46.150 A:middle L:90% vertical or peril, which this one gives us a 488 00:33:46.160 --> 00:33:50.369 A:middle L:90% coupling in the in the magnetic field in this direction 489 00:33:50.380 --> 00:33:52.269 A:middle L:90% , this one couples the magnetic field in this direction 490 00:33:52.640 --> 00:33:58.720 A:middle L:90% the cross Cll is going to couple in both directions 491 00:33:58.730 --> 00:34:00.990 A:middle L:90% and give us the answer trophic behavior. And this 492 00:34:00.990 --> 00:34:06.160 A:middle L:90% is the analysis that we did for the negative refractive 493 00:34:06.160 --> 00:34:09.099 A:middle L:90% index calculation. And what you see here the blue 494 00:34:09.099 --> 00:34:15.510 A:middle L:90% line is the case with the cross uh loops that 495 00:34:15.510 --> 00:34:19.860 A:middle L:90% shows us isa tropic. That means the negative refractive 496 00:34:19.860 --> 00:34:25.559 A:middle L:90% index is almost constant across the angle range from minus 497 00:34:27.039 --> 00:34:30.030 A:middle L:90% From zero actually to hear up to 50. And 498 00:34:30.030 --> 00:34:32.659 A:middle L:90% of course it's the same in the negative angle. 499 00:34:32.670 --> 00:34:37.099 A:middle L:90% While the two other orientations are not ice a tropic 500 00:34:37.099 --> 00:34:40.070 A:middle L:90% . They changed with angle. So here we indeed 501 00:34:40.070 --> 00:34:45.730 A:middle L:90% achieve the reflective index that is Aissa tropic in all 502 00:34:45.730 --> 00:34:47.420 A:middle L:90% directions. This is what we built. This is 503 00:34:47.420 --> 00:34:52.059 A:middle L:90% the periodic structure. Okay. Of these loops. 504 00:34:52.320 --> 00:34:53.909 A:middle L:90% And this is the random, the random, we 505 00:34:53.909 --> 00:34:59.300 A:middle L:90% built individual cells and we throw them in the material 506 00:34:59.300 --> 00:35:01.260 A:middle L:90% like you can see here the individual self for the 507 00:35:01.260 --> 00:35:06.579 A:middle L:90% random looks like this. You have the printed CLL 508 00:35:06.579 --> 00:35:08.659 A:middle L:90% and the printed probe. And we put that in 509 00:35:08.670 --> 00:35:13.550 A:middle L:90% a body of raw cell material to give us a 510 00:35:13.940 --> 00:35:16.639 A:middle L:90% absolutely equal one in the material here. And then 511 00:35:16.650 --> 00:35:20.039 A:middle L:90% we cut it and shake it and put it in 512 00:35:20.039 --> 00:35:24.829 A:middle L:90% the around the medium. Um This is some of 513 00:35:24.829 --> 00:35:29.429 A:middle L:90% the properties that we can see that the random selves 514 00:35:29.440 --> 00:35:31.480 A:middle L:90% are going to give us. Uh this is periodic 515 00:35:31.489 --> 00:35:36.179 A:middle L:90% . Okay. And this periodic here shows that we 516 00:35:36.179 --> 00:35:42.119 A:middle L:90% have a reflection represented by the red and transmission represented 517 00:35:42.119 --> 00:35:45.150 A:middle L:90% by the blue. Okay, over a very narrow 518 00:35:45.150 --> 00:35:49.139 A:middle L:90% band. So in this band the periodic material is 519 00:35:49.150 --> 00:35:53.239 A:middle L:90% reflective in this part here is transmitted. Okay, 520 00:35:53.250 --> 00:35:57.659 A:middle L:90% the layers of the material, if you have some 521 00:35:58.139 --> 00:36:00.659 A:middle L:90% disordered cells, that means cells are not the same 522 00:36:00.659 --> 00:36:04.739 A:middle L:90% size. But still you are trying to put them 523 00:36:04.750 --> 00:36:07.369 A:middle L:90% on a periodic lattice. You get this kind of 524 00:36:07.380 --> 00:36:14.119 A:middle L:90% response. You have some reflective and some transmitted and 525 00:36:14.130 --> 00:36:16.460 A:middle L:90% different parts of the frequency band. If you do 526 00:36:16.460 --> 00:36:21.409 A:middle L:90% it all random like this one here. This gives 527 00:36:21.409 --> 00:36:24.730 A:middle L:90% us very interesting result because we have what's equivalent to 528 00:36:24.730 --> 00:36:30.059 A:middle L:90% a band pass filter where you have through this band 529 00:36:30.059 --> 00:36:31.079 A:middle L:90% , which is much broader than any of the bands 530 00:36:31.079 --> 00:36:36.010 A:middle L:90% we had there. We have a very good transmission 531 00:36:36.010 --> 00:36:38.579 A:middle L:90% coefficient. This is as to one and very high 532 00:36:38.579 --> 00:36:45.460 A:middle L:90% reflection or high s 11 that means that within this 533 00:36:45.460 --> 00:36:49.260 A:middle L:90% ban the material is acts like F. S. 534 00:36:49.260 --> 00:36:52.170 A:middle L:90% S. Frequency selective service. But over a very 535 00:36:52.170 --> 00:36:55.769 A:middle L:90% wide band so that we can achieve with the periodic 536 00:36:55.780 --> 00:37:00.400 A:middle L:90% . Okay, uh against what we can achieve, 537 00:37:00.409 --> 00:37:01.619 A:middle L:90% I'm sorry, with the random. Against what we 538 00:37:01.619 --> 00:37:07.469 A:middle L:90% can achieve with the with the periodic Yes, your 539 00:37:07.469 --> 00:37:09.239 A:middle L:90% random result, is that an average over a number 540 00:37:09.239 --> 00:37:13.849 A:middle L:90% of different realizations are just one at one measure. 541 00:37:14.630 --> 00:37:17.599 A:middle L:90% uh in this case it's only one when we do 542 00:37:17.599 --> 00:37:22.960 A:middle L:90% the theoretical analysis. Okay, we are going to 543 00:37:22.969 --> 00:37:27.789 A:middle L:90% do an average based on the theoretical analysis and see 544 00:37:27.789 --> 00:37:30.199 A:middle L:90% how that is. But this is a case of 545 00:37:30.199 --> 00:37:34.940 A:middle L:90% one run the same thing with the measurements. We 546 00:37:34.940 --> 00:37:37.230 A:middle L:90% do it once and then we measured. So we 547 00:37:37.230 --> 00:37:39.780 A:middle L:90% , when we do the averaging, we don't know 548 00:37:39.789 --> 00:37:43.760 A:middle L:90% how wide sigma is going to be. If it's 549 00:37:43.760 --> 00:37:45.079 A:middle L:90% going to be abroad, that means it's going to 550 00:37:45.079 --> 00:37:49.900 A:middle L:90% have this wide band all the time or it's going 551 00:37:49.900 --> 00:37:53.300 A:middle L:90% to be like fairly in a narrow number or a 552 00:37:53.300 --> 00:37:58.670 A:middle L:90% small number of uh of sigma. Uh One of 553 00:37:58.670 --> 00:38:01.300 A:middle L:90% the things actually I have in Houston who is going 554 00:38:01.300 --> 00:38:04.699 A:middle L:90% to work on this thing from the theoretical point of 555 00:38:04.699 --> 00:38:07.769 A:middle L:90% view and one of the things and actually I need 556 00:38:07.769 --> 00:38:09.619 A:middle L:90% to run that by you very quickly is we would 557 00:38:09.619 --> 00:38:15.190 A:middle L:90% like to use the theory of random medium Okay, 558 00:38:15.199 --> 00:38:19.500 A:middle L:90% propagation through around the medium. In trying to analyze 559 00:38:19.500 --> 00:38:23.750 A:middle L:90% this. There is a method of analyzing metamaterials, 560 00:38:24.320 --> 00:38:29.809 A:middle L:90% periodic method materials that was done by Ishimaru at the 561 00:38:29.809 --> 00:38:32.710 A:middle L:90% University of Washington. And we would like to follow 562 00:38:32.719 --> 00:38:37.000 A:middle L:90% what he was doing in the propagation area to see 563 00:38:37.010 --> 00:38:42.579 A:middle L:90% if we can also apply the theory of random media 564 00:38:42.579 --> 00:38:45.769 A:middle L:90% market to this in order to simplify the analysis and 565 00:38:45.769 --> 00:38:49.119 A:middle L:90% the simulation because the way we are doing it. 566 00:38:49.130 --> 00:38:52.579 A:middle L:90% Now, the simulation is very time consuming. When 567 00:38:52.579 --> 00:38:57.289 A:middle L:90% you use HFcs or any of the other methods, 568 00:38:57.289 --> 00:39:00.489 A:middle L:90% it's very consuming, time consuming. But we hope 569 00:39:00.489 --> 00:39:04.820 A:middle L:90% that when we do the theoretical analysis, that's going 570 00:39:04.820 --> 00:39:09.539 A:middle L:90% to be uh more easy to handle than that. 571 00:39:10.519 --> 00:39:16.570 A:middle L:90% Ah, okay. One of the applications that we 572 00:39:16.570 --> 00:39:24.559 A:middle L:90% have for this is only because I'm giving this for 573 00:39:24.559 --> 00:39:30.150 A:middle L:90% wireless activity. So I have to all this uh 574 00:39:31.119 --> 00:39:34.860 A:middle L:90% one of the applications that we have for this meta 575 00:39:34.860 --> 00:39:38.969 A:middle L:90% material in terms of improving the performance of an antenna 576 00:39:38.980 --> 00:39:44.579 A:middle L:90% is take the very simple diaper, the whip antenna 577 00:39:44.590 --> 00:39:47.309 A:middle L:90% , which of course you probably heard this expression many 578 00:39:47.309 --> 00:39:52.130 A:middle L:90% , many times. You cannot beat the whip okay 579 00:39:52.139 --> 00:39:55.039 A:middle L:90% . Which is the main antenna is being used for 580 00:39:55.050 --> 00:39:59.170 A:middle L:90% on vehicles and army applications and all of that. 581 00:39:59.179 --> 00:40:01.550 A:middle L:90% Of course, whip antenna on the vehicle means that 582 00:40:01.550 --> 00:40:06.000 A:middle L:90% this is an important vehicle. Then then uh the 583 00:40:06.000 --> 00:40:07.389 A:middle L:90% whoever wants to shoot is going to shoot that vehicle 584 00:40:07.389 --> 00:40:12.110 A:middle L:90% first. So you'd like to reduce the profile or 585 00:40:12.110 --> 00:40:14.500 A:middle L:90% the size of the antenna on the vehicle so that 586 00:40:14.500 --> 00:40:17.860 A:middle L:90% it will not be easy to detect. And that's 587 00:40:17.860 --> 00:40:21.199 A:middle L:90% a different subject. We're doing lots of work in 588 00:40:21.199 --> 00:40:22.900 A:middle L:90% that area. But here, what we are doing 589 00:40:22.909 --> 00:40:27.500 A:middle L:90% , we found out that this kind of loop structure 590 00:40:27.510 --> 00:40:30.179 A:middle L:90% . Okay, in this plane here, if you 591 00:40:30.179 --> 00:40:32.940 A:middle L:90% send a signal in this direction on the plane, 592 00:40:34.309 --> 00:40:38.340 A:middle L:90% it is going to reflect back with this being high 593 00:40:38.340 --> 00:40:43.920 A:middle L:90% new material when it is high new material. Okay 594 00:40:43.920 --> 00:40:45.349 A:middle L:90% , you don't, it's going to act as if 595 00:40:45.349 --> 00:40:51.219 A:middle L:90% it's a reflector but at very small distance with respect 596 00:40:51.219 --> 00:40:52.920 A:middle L:90% to the default. So we have a die paul 597 00:40:52.920 --> 00:40:57.949 A:middle L:90% here with very small distance to this material here and 598 00:40:57.949 --> 00:41:00.630 A:middle L:90% that we found out that this is going to give 599 00:41:00.630 --> 00:41:05.349 A:middle L:90% us not the omni directional pattern of the antenna, 600 00:41:05.349 --> 00:41:07.710 A:middle L:90% but it's going to make the dipole directive in the 601 00:41:07.710 --> 00:41:12.730 A:middle L:90% azimuth play. Okay, so I can produce directive 602 00:41:12.730 --> 00:41:15.360 A:middle L:90% . P beam out of the dipole antenna in in 603 00:41:15.360 --> 00:41:20.750 A:middle L:90% asthma. If I repeat this many times instead of 604 00:41:20.750 --> 00:41:22.889 A:middle L:90% one thing like this one here, I put 12 605 00:41:22.889 --> 00:41:27.260 A:middle L:90% pins around the die Paul. Then I can increase 606 00:41:27.260 --> 00:41:30.320 A:middle L:90% again and reduce the size of the B. More 607 00:41:30.329 --> 00:41:32.369 A:middle L:90% . So if you look at this table, you 608 00:41:32.369 --> 00:41:36.579 A:middle L:90% will find that with no fins. That means The 609 00:41:36.579 --> 00:41:38.380 A:middle L:90% default in free space gives you a gain of 2.2 610 00:41:38.380 --> 00:41:40.869 A:middle L:90% DB. They should be D. B. I 611 00:41:40.880 --> 00:41:45.340 A:middle L:90% . Uh When you have to fans like this one 612 00:41:45.340 --> 00:41:47.739 A:middle L:90% here, this plane or You can get this kind 613 00:41:47.739 --> 00:41:52.280 A:middle L:90% of gain 5.4 and then all the way to 12 614 00:41:52.289 --> 00:41:55.849 A:middle L:90% . You can get 9.7 DB I out of a 615 00:41:55.849 --> 00:42:00.690 A:middle L:90% disciple which of course is very good improvement. About 616 00:42:00.690 --> 00:42:05.989 A:middle L:90% 7.5 db improvement over the simple dipole. But of 617 00:42:05.989 --> 00:42:08.320 A:middle L:90% course you get very narrow beam, which means that 618 00:42:08.900 --> 00:42:13.590 A:middle L:90% if you have a diaper like this. Okay. 619 00:42:13.590 --> 00:42:16.059 A:middle L:90% And you have the fence around it by rotating either 620 00:42:16.059 --> 00:42:19.650 A:middle L:90% the fins or the die paul, you can have 621 00:42:19.650 --> 00:42:22.960 A:middle L:90% actually scanning of the beam out of a simple dipole 622 00:42:22.969 --> 00:42:25.139 A:middle L:90% . So this is a scanning die paul, which 623 00:42:25.139 --> 00:42:29.829 A:middle L:90% you can get out of this using the meta material 624 00:42:29.920 --> 00:42:37.239 A:middle L:90% structure around uh this, I'm sorry. Okay. 625 00:42:37.250 --> 00:42:42.739 A:middle L:90% Uh This is the game. It doesn't show the 626 00:42:42.739 --> 00:42:45.889 A:middle L:90% bandwidth. Uh No, it has actually fairly good 627 00:42:45.889 --> 00:42:50.110 A:middle L:90% bandwidth. I don't have the number of the top 628 00:42:50.110 --> 00:42:52.869 A:middle L:90% of my head now, but it's fairly good good 629 00:42:52.869 --> 00:42:57.210 A:middle L:90% bandwidth. This here actually, this can give you 630 00:42:57.210 --> 00:43:00.639 A:middle L:90% an idea. Uh this is over frequency band not 631 00:43:00.639 --> 00:43:05.760 A:middle L:90% very wide here. 1.5- two GHz. The 632 00:43:05.769 --> 00:43:10.739 A:middle L:90% top of the Where is the simple? The Die 633 00:43:10.739 --> 00:43:14.420 A:middle L:90% Paul is the adopted one. So the dotted here 634 00:43:14.900 --> 00:43:17.460 A:middle L:90% Is the simple dipole that gives you about 2.2 or 635 00:43:17.460 --> 00:43:22.010 A:middle L:90% around two. Actually, here, it's this is 636 00:43:22.010 --> 00:43:24.260 A:middle L:90% measured data by the way, is not simulated this 637 00:43:24.260 --> 00:43:30.469 A:middle L:90% measure. But if you uh if you go to 638 00:43:30.469 --> 00:43:37.710 A:middle L:90% the if you add the two, the two pens 639 00:43:37.710 --> 00:43:43.780 A:middle L:90% around it, uh then you can yeah, you 640 00:43:43.780 --> 00:43:46.130 A:middle L:90% can get of course when you have a simple die 641 00:43:46.130 --> 00:43:49.880 A:middle L:90% pole, there's no backlog. It's going to be 642 00:43:49.889 --> 00:43:53.190 A:middle L:90% omni directional, but if you add the defense, 643 00:43:53.199 --> 00:43:57.699 A:middle L:90% then you're going to have front and back. So 644 00:43:57.699 --> 00:44:01.949 A:middle L:90% this this is the front um This is the this 645 00:44:01.949 --> 00:44:06.730 A:middle L:90% is the front. I'm sorry. Yeah, this 646 00:44:06.730 --> 00:44:08.639 A:middle L:90% is the front simulated. And this is the front 647 00:44:08.639 --> 00:44:13.460 A:middle L:90% measure. Okay, so you can see that we 648 00:44:13.460 --> 00:44:17.099 A:middle L:90% have gained about 2-3 d be above. Uh the 649 00:44:17.110 --> 00:44:22.039 A:middle L:90% simple deport at the same time. The back lobe 650 00:44:22.050 --> 00:44:23.659 A:middle L:90% , which shows the directive Itty they have directed the 651 00:44:23.659 --> 00:44:27.500 A:middle L:90% beam is is going to be shown by this here 652 00:44:27.989 --> 00:44:31.079 A:middle L:90% . Okay, so if you take uh from here 653 00:44:31.079 --> 00:44:36.630 A:middle L:90% to here, that's the front tobacco issue simulated from 654 00:44:36.639 --> 00:44:38.219 A:middle L:90% the green to black. That's the front to back 655 00:44:38.219 --> 00:44:43.920 A:middle L:90% ratio measure. And of course the die paul, 656 00:44:44.170 --> 00:44:45.809 A:middle L:90% simple dipole doesn't have back. So it is, 657 00:44:45.809 --> 00:44:50.179 A:middle L:90% it is constant in all directions, but this is 658 00:44:50.179 --> 00:44:54.500 A:middle L:90% over frequency. Now this is the simulated radiation pattern 659 00:44:54.889 --> 00:44:58.210 A:middle L:90% . Uh and actually we have measured but we have 660 00:44:58.210 --> 00:45:00.619 A:middle L:90% measured for this one which is the two fins. 661 00:45:00.630 --> 00:45:02.599 A:middle L:90% And as you can see, this is the disciple 662 00:45:02.599 --> 00:45:06.989 A:middle L:90% in this direction and it's more directive here than in 663 00:45:06.989 --> 00:45:09.260 A:middle L:90% the other direction. And uh in the in the 664 00:45:09.269 --> 00:45:14.030 A:middle L:90% elevation plane, you still have the same pattern which 665 00:45:14.030 --> 00:45:17.630 A:middle L:90% is peak and at 90 degrees and zero at 0 666 00:45:17.630 --> 00:45:22.280 A:middle L:90% 180 degrees. This one is the 12th in which 667 00:45:22.280 --> 00:45:29.260 A:middle L:90% gives you higher again, uh the bandwidth is is 668 00:45:29.260 --> 00:45:31.030 A:middle L:90% is a good question. But again, like when 669 00:45:31.030 --> 00:45:35.679 A:middle L:90% you design for simple type all it has certain bandwidth 670 00:45:35.679 --> 00:45:38.139 A:middle L:90% as well. Okay, another application for the negative 671 00:45:38.139 --> 00:45:43.460 A:middle L:90% refractive index is going to be in the Rotman lines 672 00:45:44.079 --> 00:45:47.219 A:middle L:90% and what we have here, we have this is 673 00:45:47.219 --> 00:45:53.639 A:middle L:90% the, the old rotten ones starting from here and 674 00:45:53.639 --> 00:45:58.239 A:middle L:90% going to here and then radiating in this direction. 675 00:45:58.250 --> 00:46:00.739 A:middle L:90% So this is the beam surface, our beam array 676 00:46:00.739 --> 00:46:05.619 A:middle L:90% and this is the receiving array and this is transmitting 677 00:46:05.619 --> 00:46:09.369 A:middle L:90% array. If we use negative refractive index material between 678 00:46:09.369 --> 00:46:14.250 A:middle L:90% these two services as I can show here in this 679 00:46:14.260 --> 00:46:17.179 A:middle L:90% sketch, then I can actually bring this all the 680 00:46:17.179 --> 00:46:21.949 A:middle L:90% way to here. And that is going to give 681 00:46:21.949 --> 00:46:24.030 A:middle L:90% me through the optics of the lens, the same 682 00:46:24.030 --> 00:46:28.889 A:middle L:90% performance as a lens that has this dimension. So 683 00:46:28.889 --> 00:46:31.860 A:middle L:90% I'm reducing the size from this dimension to this dimension 684 00:46:31.860 --> 00:46:37.469 A:middle L:90% here on the sides in order to prevent reflections of 685 00:46:37.469 --> 00:46:40.909 A:middle L:90% the side of the lens. Usually in rotten lands 686 00:46:40.909 --> 00:46:45.000 A:middle L:90% , we either put terminations on the side or put 687 00:46:45.010 --> 00:46:50.659 A:middle L:90% absorbers uh in which both cases you do not, 688 00:46:50.670 --> 00:46:54.159 A:middle L:90% of course the energy is lost over there. Using 689 00:46:54.159 --> 00:46:58.539 A:middle L:90% meta material, we can use an ebc structure on 690 00:46:58.539 --> 00:47:01.750 A:middle L:90% the sides that is going to prevent any surface were 691 00:47:01.750 --> 00:47:06.619 A:middle L:90% from going there and it's going to be reflected and 692 00:47:06.619 --> 00:47:12.110 A:middle L:90% add coherently with the radiation that's coming from this direction 693 00:47:12.110 --> 00:47:15.510 A:middle L:90% here. And that's going to increase the amount of 694 00:47:15.510 --> 00:47:19.710 A:middle L:90% energy that is transmitting from the beam array to the 695 00:47:20.179 --> 00:47:22.449 A:middle L:90% to this. Our receiver right here. We haven't 696 00:47:22.449 --> 00:47:25.309 A:middle L:90% built this one yet because it's going to depend on 697 00:47:25.309 --> 00:47:30.150 A:middle L:90% using random material here and some fancy E B G 698 00:47:30.150 --> 00:47:32.780 A:middle L:90% on the sides here. Okay, the next thing 699 00:47:32.789 --> 00:47:36.940 A:middle L:90% and I have to move faster. The meta services 700 00:47:36.949 --> 00:47:40.769 A:middle L:90% uh meta services actually is a general word for uh 701 00:47:40.780 --> 00:47:46.460 A:middle L:90% any surface that gives you something different than the simple 702 00:47:46.460 --> 00:47:50.190 A:middle L:90% reflection of the ground plane. If you have a 703 00:47:50.190 --> 00:47:52.369 A:middle L:90% ground plane, you get a reflection of the surface 704 00:47:52.380 --> 00:47:58.230 A:middle L:90% with 100 and 80 degree phase shift. The signal 705 00:47:58.230 --> 00:48:00.449 A:middle L:90% going in and coming out has 100 and 80 degree 706 00:48:00.449 --> 00:48:02.670 A:middle L:90% phase shift. That's why if you have an antenna 707 00:48:02.679 --> 00:48:06.289 A:middle L:90% and you want the radiation to be strong above the 708 00:48:06.289 --> 00:48:07.860 A:middle L:90% ground plane. Then you try to put the antenna 709 00:48:07.860 --> 00:48:13.019 A:middle L:90% quarter wavelength Above the ground plate. So the signal 710 00:48:13.019 --> 00:48:15.989 A:middle L:90% goes suffers under 80° comes back and then adds coherently 711 00:48:15.989 --> 00:48:19.579 A:middle L:90% with your radiation. Uh The E. B. 712 00:48:19.579 --> 00:48:22.099 A:middle L:90% G structure is something that is very thin or the 713 00:48:22.099 --> 00:48:27.730 A:middle L:90% metal surface in general is service that's very thin and 714 00:48:27.730 --> 00:48:30.440 A:middle L:90% gives you close to zero degree face reflection when you 715 00:48:30.440 --> 00:48:36.449 A:middle L:90% get zero face degree his zero degree face reflection. 716 00:48:36.460 --> 00:48:39.550 A:middle L:90% Then the signal is going to add coherently with very 717 00:48:39.550 --> 00:48:43.730 A:middle L:90% small distance between the antenna and the surface. And 718 00:48:43.730 --> 00:48:49.280 A:middle L:90% the meta surface can be uh sort of uh realized 719 00:48:49.469 --> 00:48:53.360 A:middle L:90% with either high new value with this E. B 720 00:48:53.360 --> 00:48:59.199 A:middle L:90% . G structure which gives you high impedance. The 721 00:48:59.210 --> 00:49:02.369 A:middle L:90% structures are sometimes called in addition to metro surface, 722 00:49:02.380 --> 00:49:08.480 A:middle L:90% high impedance surface or magnetic surface. Perfect magnetic conducting 723 00:49:08.489 --> 00:49:13.920 A:middle L:90% artificial magnetic conductor AMC R E. B. G 724 00:49:13.920 --> 00:49:16.809 A:middle L:90% is one of the structures that were devised to do 725 00:49:16.809 --> 00:49:20.469 A:middle L:90% the same thing and they actually are the ones that 726 00:49:20.480 --> 00:49:23.690 A:middle L:90% most commonly used. Uh So they are compact in 727 00:49:23.690 --> 00:49:29.849 A:middle L:90% size and give you this kind of reflection phase versus 728 00:49:29.849 --> 00:49:32.789 A:middle L:90% frequency. So the reflection phase is centered around zero 729 00:49:32.800 --> 00:49:37.590 A:middle L:90% and we generally accept plus or minus 90 degree okay 730 00:49:37.590 --> 00:49:42.110 A:middle L:90% of reflection phase of this service. And one of 731 00:49:42.110 --> 00:49:49.380 A:middle L:90% the original forms of this CBgb was due to steven 732 00:49:49.380 --> 00:49:51.699 A:middle L:90% piper out of U. C. L. A 733 00:49:51.710 --> 00:49:55.949 A:middle L:90% . Back in in the 1999 along with other people 734 00:49:55.960 --> 00:50:00.010 A:middle L:90% at U C. L. A. And this 735 00:50:00.010 --> 00:50:02.230 A:middle L:90% is a mushroom structure where you have patches and then 736 00:50:02.230 --> 00:50:06.239 A:middle L:90% connections to the ground plane like this. And that 737 00:50:06.239 --> 00:50:08.030 A:middle L:90% does two things gives you the reflection phase that you 738 00:50:08.030 --> 00:50:12.989 A:middle L:90% want and kills any surface with that propagates here. 739 00:50:13.059 --> 00:50:15.960 A:middle L:90% So it reduces the mutual coupling between elements and I 740 00:50:15.969 --> 00:50:20.699 A:middle L:90% can give you some other properties. The meta service 741 00:50:20.699 --> 00:50:22.630 A:middle L:90% sometime also is used not just to kill the surface 742 00:50:22.630 --> 00:50:27.619 A:middle L:90% where but to launch leaky way. Okay. And 743 00:50:27.619 --> 00:50:31.480 A:middle L:90% that's a different structure that can be devised as well 744 00:50:31.860 --> 00:50:35.880 A:middle L:90% . So this is the effect of the size of 745 00:50:35.880 --> 00:50:38.429 A:middle L:90% the patches. Okay. And how it changes the 746 00:50:38.440 --> 00:50:44.960 A:middle L:90% reflection phase profile so that you can shift the frequency 747 00:50:44.969 --> 00:50:49.590 A:middle L:90% of uh the best performance of the body structure by 748 00:50:49.590 --> 00:50:52.949 A:middle L:90% controlling the size of the patches. If you put 749 00:50:52.949 --> 00:50:55.690 A:middle L:90% an antenna above this. And this is an example 750 00:50:55.699 --> 00:51:00.719 A:middle L:90% by now cano back a few years ago. Uh 751 00:51:00.730 --> 00:51:07.260 A:middle L:90% This is uh seniors antenna that you put it short 752 00:51:07.260 --> 00:51:08.969 A:middle L:90% distance above the B. G. And then you 753 00:51:08.969 --> 00:51:13.289 A:middle L:90% get the high performance. Uh So this is one 754 00:51:13.289 --> 00:51:15.199 A:middle L:90% form of it, the squares another and there are 755 00:51:15.199 --> 00:51:17.050 A:middle L:90% lots of lots of forms of E. B. 756 00:51:17.050 --> 00:51:21.179 A:middle L:90% D. Now, what we did the BBg by 757 00:51:21.179 --> 00:51:24.610 A:middle L:90% itself is a narrow band. So we decided that 758 00:51:24.610 --> 00:51:28.739 A:middle L:90% we'd like to have it operating over broadband. So 759 00:51:28.739 --> 00:51:31.280 A:middle L:90% we did two things again, that's the PhD that 760 00:51:31.559 --> 00:51:37.369 A:middle L:90% sandy Paretti is doing uh the E B G here 761 00:51:37.380 --> 00:51:40.190 A:middle L:90% is uh either progressive as you can see here. 762 00:51:40.199 --> 00:51:45.000 A:middle L:90% We divide the surface into different regions with different dimensions 763 00:51:45.010 --> 00:51:47.590 A:middle L:90% or we stack layers of E B G on the 764 00:51:47.590 --> 00:51:51.710 A:middle L:90% top of the other. Uh to give us each 765 00:51:51.710 --> 00:51:54.539 A:middle L:90% one is going to resonate a certain frequency. These 766 00:51:54.539 --> 00:51:59.900 A:middle L:90% sketches actually are ugly sketches from the first time. 767 00:51:59.900 --> 00:52:01.599 A:middle L:90% We envision this thing here, we have much better 768 00:52:01.610 --> 00:52:06.110 A:middle L:90% uh ideas now than just doing it this way. 769 00:52:06.119 --> 00:52:08.550 A:middle L:90% But again, they centered on changing the dimensions or 770 00:52:08.550 --> 00:52:13.039 A:middle L:90% stacking them. And this is the irregular E B 771 00:52:13.039 --> 00:52:15.929 A:middle L:90% G, the blue one. The red one is 772 00:52:15.929 --> 00:52:19.039 A:middle L:90% the progressive and you can see you can have much 773 00:52:19.039 --> 00:52:23.360 A:middle L:90% slower phase slope across frequency. That means that you 774 00:52:23.360 --> 00:52:29.420 A:middle L:90% can get the pipeline plus or-90° over extremely wideband 775 00:52:29.429 --> 00:52:32.449 A:middle L:90% ratio of 4-1 or even more than 4-1. This 776 00:52:32.449 --> 00:52:37.679 A:middle L:90% one for the stack and again, uh this one 777 00:52:37.690 --> 00:52:42.309 A:middle L:90% actually the red here is the uniform and the blue 778 00:52:42.309 --> 00:52:45.900 A:middle L:90% is the stacked one. Uh Now the trick here 779 00:52:45.909 --> 00:52:52.440 A:middle L:90% is how to also do the dB regime and change 780 00:52:52.449 --> 00:52:57.079 A:middle L:90% the frequency dynamically, make it tunable. Okay. 781 00:52:57.090 --> 00:53:00.199 A:middle L:90% And I have someone working on this and hopefully we'll 782 00:53:00.199 --> 00:53:05.630 A:middle L:90% get some interesting designs out of that. Um and 783 00:53:05.630 --> 00:53:08.130 A:middle L:90% then the student's name is chris Milligan, he is 784 00:53:08.130 --> 00:53:14.880 A:middle L:90% devising some ways of producing its tunable mbg surface. 785 00:53:15.349 --> 00:53:19.949 A:middle L:90% And this here is the old idea of using var 786 00:53:19.949 --> 00:53:22.400 A:middle L:90% actor diodes and the idea here is that you change 787 00:53:22.400 --> 00:53:28.030 A:middle L:90% the capacitance is and of course the conductance is which 788 00:53:28.030 --> 00:53:31.099 A:middle L:90% are represented by these guys here are going to stay 789 00:53:31.099 --> 00:53:34.710 A:middle L:90% fixed but by doing that, you are going to 790 00:53:34.710 --> 00:53:38.420 A:middle L:90% move the face curve like you see here. So 791 00:53:38.420 --> 00:53:42.900 A:middle L:90% this way you tune the BBg structure to resonate at 792 00:53:42.900 --> 00:53:46.920 A:middle L:90% different frequencies. Uh this is another way of doing 793 00:53:46.920 --> 00:53:50.960 A:middle L:90% it. This is to produce dual band E B 794 00:53:50.960 --> 00:53:53.269 A:middle L:90% G. Okay, so you can produce again using 795 00:53:53.280 --> 00:53:57.960 A:middle L:90% some kind of capacitive elements in order to control the 796 00:53:57.960 --> 00:54:01.510 A:middle L:90% frequencies at which the two residences happened. You can 797 00:54:01.510 --> 00:54:06.650 A:middle L:90% also use man's in order to do the tuning of 798 00:54:06.659 --> 00:54:09.289 A:middle L:90% uh the E B. G structure and move the 799 00:54:09.289 --> 00:54:15.260 A:middle L:90% frequency as you can see here. This is the 800 00:54:15.639 --> 00:54:19.360 A:middle L:90% , the performance of of the, the structure here 801 00:54:19.739 --> 00:54:22.789 A:middle L:90% at different frequencies. So you can do the dynamic 802 00:54:22.800 --> 00:54:28.260 A:middle L:90% changes. Okay, uh I mean dynamically change the 803 00:54:28.260 --> 00:54:30.260 A:middle L:90% phase to move the frequency of the B. G 804 00:54:30.739 --> 00:54:35.099 A:middle L:90% . This is the progressive one uh and we got 805 00:54:35.099 --> 00:54:37.909 A:middle L:90% a little bit smarter here and we still have different 806 00:54:37.909 --> 00:54:43.059 A:middle L:90% dimensions of the patches that make the E B G 807 00:54:43.070 --> 00:54:45.559 A:middle L:90% . And we have it on a single height. 808 00:54:46.039 --> 00:54:50.809 A:middle L:90% Okay, this is still with pins but we can 809 00:54:50.809 --> 00:54:52.550 A:middle L:90% also do the same thing without pains. We can 810 00:54:52.550 --> 00:54:57.929 A:middle L:90% realize the capacitance and conductance of the BBg without depends 811 00:54:57.940 --> 00:55:01.380 A:middle L:90% and this is a theoretical or uh study that we 812 00:55:01.380 --> 00:55:05.400 A:middle L:90% are actually building this or in the process of building 813 00:55:05.400 --> 00:55:07.699 A:middle L:90% this. Now we build it with a spiral like 814 00:55:07.699 --> 00:55:10.849 A:middle L:90% this which we know is very wide band and we 815 00:55:10.849 --> 00:55:15.679 A:middle L:90% have a very short distance above the structure. The 816 00:55:15.679 --> 00:55:19.320 A:middle L:90% progressive or the white van de beek structure. Uh 817 00:55:19.329 --> 00:55:22.360 A:middle L:90% This is the phase difference. Uh The face reflection 818 00:55:22.369 --> 00:55:27.619 A:middle L:90% difference between uh the uniform which is the blue and 819 00:55:27.619 --> 00:55:30.909 A:middle L:90% the progressive which is the red. And you can 820 00:55:30.909 --> 00:55:35.800 A:middle L:90% see the red is shallower or lower in slope than 821 00:55:35.800 --> 00:55:38.559 A:middle L:90% the blue. That thus it gives us wider bandwidth 822 00:55:38.940 --> 00:55:44.550 A:middle L:90% . This is the radiation pattern of the different things 823 00:55:44.550 --> 00:55:45.800 A:middle L:90% with the E. B. G. Or without 824 00:55:45.800 --> 00:55:50.090 A:middle L:90% it over a very wide frequency band. And we 825 00:55:50.090 --> 00:55:53.980 A:middle L:90% show that you can indeed get higher gain. Uh 826 00:55:53.989 --> 00:55:58.909 A:middle L:90% This actually is the return loss showing that the spiral 827 00:55:58.909 --> 00:56:01.130 A:middle L:90% without anything. And then the spiral with the E 828 00:56:01.130 --> 00:56:05.619 A:middle L:90% . B. G. Structure uniform and progressive. 829 00:56:05.630 --> 00:56:07.760 A:middle L:90% And here we should again and the red one which 830 00:56:07.760 --> 00:56:10.619 A:middle L:90% gives us the highest gain is the one with the 831 00:56:10.619 --> 00:56:14.030 A:middle L:90% progressive E. B. G. The Blue one 832 00:56:14.039 --> 00:56:17.329 A:middle L:90% is the spiral in freeze bit. So increase the 833 00:56:17.329 --> 00:56:23.260 A:middle L:90% gain because of the reflection that the uh is of 834 00:56:23.260 --> 00:56:28.710 A:middle L:90% the reflected signal of the service that as coherently with 835 00:56:28.710 --> 00:56:31.550 A:middle L:90% the radiated fields. And also we looked at the 836 00:56:31.550 --> 00:56:36.480 A:middle L:90% X. R. Issue and it is getting is 837 00:56:36.480 --> 00:56:40.969 A:middle L:90% giving us good results with that. Uh So the 838 00:56:40.980 --> 00:56:44.699 A:middle L:90% the spire an antenna with progressive E. B. 839 00:56:44.699 --> 00:56:47.420 A:middle L:90% G. It gives us higher gain and better both 840 00:56:47.420 --> 00:56:51.570 A:middle L:90% side axle ratio. And of course you can put 841 00:56:51.579 --> 00:56:58.030 A:middle L:90% the antenna very short height up of the progressive the 842 00:56:58.030 --> 00:57:00.530 A:middle L:90% E. B. G structure. So you don't 843 00:57:00.530 --> 00:57:02.360 A:middle L:90% have high profile and tennis or you're just the size 844 00:57:02.360 --> 00:57:08.090 A:middle L:90% of it. Uh Now the adaptive meta surface or 845 00:57:08.090 --> 00:57:10.590 A:middle L:90% adaptive E B. G. Because I can control 846 00:57:10.590 --> 00:57:15.869 A:middle L:90% now the frequency at and the phase that I can 847 00:57:15.869 --> 00:57:19.170 A:middle L:90% produce out of the surface. I can use that 848 00:57:19.179 --> 00:57:23.989 A:middle L:90% as a new uh element in my tool set and 849 00:57:23.989 --> 00:57:29.800 A:middle L:90% designing cognitive radar because in cognitive radar you would like 850 00:57:29.800 --> 00:57:35.190 A:middle L:90% to control the reflection and the radar cross section of 851 00:57:35.190 --> 00:57:37.840 A:middle L:90% the structure that you have so that when someone tries 852 00:57:37.840 --> 00:57:42.679 A:middle L:90% to detect you or detect your range you can actually 853 00:57:42.679 --> 00:57:46.349 A:middle L:90% send the wrong signal to the the signal that's coming 854 00:57:46.360 --> 00:57:50.460 A:middle L:90% to the transmit and transmitter that's coming to you. 855 00:57:51.429 --> 00:57:54.449 A:middle L:90% So by changing the phase the reflective phase then you 856 00:57:54.449 --> 00:57:59.889 A:middle L:90% can use that your advantage in the overall process of 857 00:57:59.889 --> 00:58:04.690 A:middle L:90% designing the cognitive radar Again, because of time I'm 858 00:58:04.690 --> 00:58:07.750 A:middle L:90% going to go through this very quickly. This is 859 00:58:07.750 --> 00:58:12.119 A:middle L:90% the concept of the cognitive radar as was published back 860 00:58:12.119 --> 00:58:15.250 A:middle L:90% in 2006 by Salmon Hagen. Uh This is a 861 00:58:15.250 --> 00:58:19.480 A:middle L:90% transmitter and then the environment is going to affect the 862 00:58:19.480 --> 00:58:23.449 A:middle L:90% return and then the cognition here is that you adjust 863 00:58:23.449 --> 00:58:29.050 A:middle L:90% things in your system based on the reflected signal that's 864 00:58:29.050 --> 00:58:30.840 A:middle L:90% coming from the effect of the environment. So the 865 00:58:30.840 --> 00:58:32.989 A:middle L:90% reflection phase is one of the things that you will 866 00:58:32.989 --> 00:58:37.500 A:middle L:90% be able to control. Uh These are some of 867 00:58:37.500 --> 00:58:40.039 A:middle L:90% the courts that Hagen had in his uh in his 868 00:58:40.039 --> 00:58:47.449 A:middle L:90% paper and about how coming to radar can benefit from 869 00:58:47.920 --> 00:58:52.809 A:middle L:90% playing with the environment so that you can you can 870 00:58:52.820 --> 00:58:55.519 A:middle L:90% do the environment with the with the information that you 871 00:58:55.519 --> 00:59:00.570 A:middle L:90% collect from it. The adaptive phase reflection phase is 872 00:59:00.570 --> 00:59:02.889 A:middle L:90% the main idea that we have here with the with 873 00:59:02.900 --> 00:59:06.980 A:middle L:90% this kind of service, the metal services. So 874 00:59:06.980 --> 00:59:10.650 A:middle L:90% it's adaptive lee control the environment and then use the 875 00:59:10.650 --> 00:59:15.769 A:middle L:90% false target uh information and radar jamming system. So 876 00:59:15.769 --> 00:59:20.070 A:middle L:90% the idea here is that to produce the wrong information 877 00:59:20.070 --> 00:59:22.840 A:middle L:90% for the jammers. Uh The idea of this service 878 00:59:22.840 --> 00:59:28.150 A:middle L:90% can also be used in the digital radio frequency memory 879 00:59:28.150 --> 00:59:30.849 A:middle L:90% which is there from the RFM which is another thing 880 00:59:30.849 --> 00:59:36.880 A:middle L:90% that we are interested in in the dano in the 881 00:59:36.889 --> 00:59:38.400 A:middle L:90% next two minutes. Let me do that very quickly 882 00:59:38.429 --> 00:59:42.159 A:middle L:90% . We know the carbon nanotubes. They are single 883 00:59:42.159 --> 00:59:45.699 A:middle L:90% wall multi wall and there are different structures for them 884 00:59:45.710 --> 00:59:50.579 A:middle L:90% that will make them either conducting or semiconducting depending on 885 00:59:50.579 --> 00:59:52.570 A:middle L:90% how you arrange this. And this is made out 886 00:59:52.570 --> 00:59:58.730 A:middle L:90% of graphene rolled into these cylinders here and what we 887 00:59:58.730 --> 01:00:01.329 A:middle L:90% did, we built patches out of the carbon nanotubes 888 01:00:01.710 --> 01:00:06.429 A:middle L:90% uh and we looked at the patches, the performance 889 01:00:06.429 --> 01:00:09.190 A:middle L:90% of them and we use try to use the patch 890 01:00:09.199 --> 01:00:13.989 A:middle L:90% as gas sensors. Uh So gas sensor because some 891 01:00:13.989 --> 01:00:15.500 A:middle L:90% of the elements in the patch are going to be 892 01:00:15.500 --> 01:00:22.690 A:middle L:90% semiconducting and they are going to change residents frequency according 893 01:00:22.690 --> 01:00:27.309 A:middle L:90% to the gas that's in the immediate neighborhood of the 894 01:00:27.309 --> 01:00:30.550 A:middle L:90% patch. So we built this patch which is a 895 01:00:30.559 --> 01:00:36.139 A:middle L:90% patch fed by a slot like this, which we 896 01:00:36.139 --> 01:00:37.590 A:middle L:90% know and have all the equations. And then this 897 01:00:37.590 --> 01:00:42.230 A:middle L:90% is the mesh patch that we built out of the 898 01:00:42.230 --> 01:00:45.610 A:middle L:90% carbon nanotube. So the black one is the conductive 899 01:00:45.619 --> 01:00:52.059 A:middle L:90% lines and the white ones or the light lines are 900 01:00:52.059 --> 01:00:57.329 A:middle L:90% the ones using semiconducting carbon nanotubes that are going to 901 01:00:57.329 --> 01:01:01.630 A:middle L:90% change the frequency according to the gas content. So 902 01:01:01.630 --> 01:01:07.820 A:middle L:90% this patch can be used for communication through this and 903 01:01:07.820 --> 01:01:12.110 A:middle L:90% through the gas gas sensor using this. So, 904 01:01:12.119 --> 01:01:15.769 A:middle L:90% dual use kind of patch. This is the structure 905 01:01:15.769 --> 01:01:19.570 A:middle L:90% of it. And this is the effect of the 906 01:01:19.570 --> 01:01:22.510 A:middle L:90% meshing because now we have the patch made out of 907 01:01:22.510 --> 01:01:24.929 A:middle L:90% um mesh which makes it work differently. This is 908 01:01:24.929 --> 01:01:29.320 A:middle L:90% the pattern of that measure gas. Here is the 909 01:01:29.320 --> 01:01:35.940 A:middle L:90% gas sensing that we did uh the analysis by changing 910 01:01:35.940 --> 01:01:39.389 A:middle L:90% the amount of gas and in this case you are 911 01:01:39.389 --> 01:01:45.739 A:middle L:90% talking about ammonia, we can change the resonance frequency 912 01:01:45.110 --> 01:01:50.929 A:middle L:90% of the dielectric patch. Like this. So, 913 01:01:50.940 --> 01:01:53.659 A:middle L:90% by detecting the frequency or by measuring the frequency, 914 01:01:53.670 --> 01:01:58.019 A:middle L:90% then we'll know what kind of concentration we have. 915 01:01:59.210 --> 01:02:01.500 A:middle L:90% This actually we did this uh sort of a little 916 01:02:01.500 --> 01:02:06.699 A:middle L:90% bit more naively because the numbers we used in the 917 01:02:06.699 --> 01:02:12.380 A:middle L:90% analysis 1000 up to 10,000 parts per million of ammonia 918 01:02:12.389 --> 01:02:15.389 A:middle L:90% . That's not realistic number. These amounts are enough 919 01:02:15.389 --> 01:02:17.980 A:middle L:90% to kill a whole town of course, would like 920 01:02:17.980 --> 01:02:22.949 A:middle L:90% to detect very, very low level of ammonia. 921 01:02:22.960 --> 01:02:27.639 A:middle L:90% So we found out that if you add perhaps to 922 01:02:27.639 --> 01:02:32.170 A:middle L:90% the carbon nanotube, then you can get Responses of 923 01:02:32.170 --> 01:02:37.099 A:middle L:90% about 50 parts per million or even loss. The 924 01:02:37.099 --> 01:02:40.599 A:middle L:90% other thing in the patch, it has polarization selectivity 925 01:02:40.610 --> 01:02:45.199 A:middle L:90% because the patch is made out of lines arranged this 926 01:02:45.199 --> 01:02:46.500 A:middle L:90% way. So it's going to reduce it better. 927 01:02:46.510 --> 01:02:50.889 A:middle L:90% If the radiation in the direction of the lines then 928 01:02:50.889 --> 01:02:53.610 A:middle L:90% it's orthogonal. And we measured the some of the 929 01:02:53.610 --> 01:02:58.190 A:middle L:90% patches that have different levels of thickness and stuff. 930 01:02:58.199 --> 01:03:01.550 A:middle L:90% And these are the results for the co and across 931 01:03:01.559 --> 01:03:07.139 A:middle L:90% performance. Uh So I guess this in conclusion we 932 01:03:07.139 --> 01:03:12.059 A:middle L:90% have all these are kind of elements in the toolbox 933 01:03:12.059 --> 01:03:15.219 A:middle L:90% that we can use to improve the antenna, reduce 934 01:03:15.219 --> 01:03:17.840 A:middle L:90% the size of it, make it low profile and 935 01:03:17.840 --> 01:03:22.230 A:middle L:90% using it for some applications like sensors and cognitive reader 936 01:03:22.500 --> 01:03:27.139 A:middle L:90% and lots of others. But the main thing is 937 01:03:27.139 --> 01:03:30.360 A:middle L:90% reduce the size of the antenna and the profile as 938 01:03:30.360 --> 01:03:34.550 A:middle L:90% much as you can without affecting the performance of. 939 01:03:35.699 --> 01:03:42.429 A:middle L:90% Thank you. Yeah. Yeah. Ok. Any 940 01:03:42.429 --> 01:03:44.369 A:middle L:90% question? I think I used a little bit more 941 01:03:44.369 --> 01:03:45.809 A:middle L:90% than my time. But if you have any questions 942 01:03:45.820 --> 01:03:50.719 A:middle L:90% Yes. Gary is the use of synthetic material. 943 01:03:50.719 --> 01:03:57.309 A:middle L:90% The primary focus of came around. Mhm. In 944 01:03:57.309 --> 01:04:00.309 A:middle L:90% other words that you've forgotten everything. Yeah. Ordinary 945 01:04:00.889 --> 01:04:03.000 A:middle L:90% . Yeah. No, no, no, no 946 01:04:03.010 --> 01:04:10.739 A:middle L:90% , of course not. Well actually, these three 947 01:04:10.739 --> 01:04:14.519 A:middle L:90% topics I talked about today along with other techniques we 948 01:04:14.519 --> 01:04:16.110 A:middle L:90% are using to reduce the size of the antenna. 949 01:04:16.590 --> 01:04:19.329 A:middle L:90% Okay, I can I can talk in detail for 950 01:04:19.329 --> 01:04:23.239 A:middle L:90% a whole day. Okay. But the other methods 951 01:04:23.250 --> 01:04:26.500 A:middle L:90% uh for instance, one other thing we are doing 952 01:04:26.889 --> 01:04:30.409 A:middle L:90% okay, we are building a spherical disciples. They 953 01:04:30.409 --> 01:04:31.809 A:middle L:90% don't have anything to do with math materials but they 954 01:04:31.809 --> 01:04:35.820 A:middle L:90% are mainly basically they are depending on trying to have 955 01:04:35.829 --> 01:04:41.449 A:middle L:90% a very good matching of dai pole made out of 956 01:04:41.449 --> 01:04:44.750 A:middle L:90% a sphere that is going to give you the same 957 01:04:44.750 --> 01:04:47.409 A:middle L:90% resonance and the same performance as along with Anton. 958 01:04:48.090 --> 01:04:51.969 A:middle L:90% Okay, that's that's one thing uh there are lots 959 01:04:51.969 --> 01:04:57.489 A:middle L:90% of other types of antennas that that that we developed 960 01:04:57.489 --> 01:05:00.969 A:middle L:90% beside this one. So this is only one sort 961 01:05:00.969 --> 01:05:02.789 A:middle L:90% of avenue in what we are doing but we have 962 01:05:02.800 --> 01:05:19.960 A:middle L:90% electrically small antennas Antanas uh um uh This is 44° 963 01:05:19.960 --> 01:05:27.010 A:middle L:90% in. What is that philadelphia? Okay. Um 964 01:05:27.690 --> 01:05:33.599 A:middle L:90% the other other antennas of different different kinds, we 965 01:05:33.599 --> 01:05:39.159 A:middle L:90% do lots of work on things like the rotten lines 966 01:05:39.159 --> 01:05:43.300 A:middle L:90% and other antennas. But the key thing is the 967 01:05:43.300 --> 01:05:46.469 A:middle L:90% antennas that are going to be carried on a vehicle 968 01:05:46.480 --> 01:05:50.210 A:middle L:90% with very low profile and with very high performance. 969 01:05:50.590 --> 01:05:55.010 A:middle L:90% So that's the one of the main goals that we 970 01:05:55.019 --> 01:06:03.230 A:middle L:90% that we have. Yeah, other questions. Thank 971 01:06:03.230 --> 01:06:10.519 A:middle L:90% you. Okay, I'm still not going to answer 972 01:06:10.519 --> 01:06:15.920 A:middle L:90% this. Mhm. Okay, thank you very much 973 01:06:16.690 --> A:middle L:90% . No