Browsing by Author "Suh, Seong-Youp"
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- A Comprehensive Investigation of New Planar Wideband AntennasSuh, Seong-Youp (Virginia Tech, 2002-07-29)Broadband wireless communications require wideband antennas to support large number of users and higher data rates. Desirable features of a wideband antenna are low-profile, dual-polarization and wide bandwidth in a compact size. Many existing wideband antennas are large in size and some have only circular polarization. On the other hand low-profile, dual-polarized antennas frequently have limited bandwidth. This dissertation reports on results from original research into several new wideband antennas. All are compact and planar, and many are low-profile and dual-polarized. Since 1994, Virginia Tech Antenna Group (VTAG) has performed research on the wideband, low-profile and dual-polarized antennas of compact size. This research resulted in the following antenna innovations: the Fourpoint, Fourtear, PICA (Planar Inverted Cone Antenna), diPICA (dipole PICA) and LPdiPICA (Low-Profile diPICA) antennas. They are all planar in geometry so one can easily construct them in a compact size. The antennas were characterized and investigated with extensive simulations and measurements. The computed and measured data demonstrates that some of the antennas appear to have the characteristics of the self-complementary antenna and most of the proposed antennas provide more than a 10:1 impedance bandwidth for a VSWR < 2. Patterns, however, are degraded at the high end of the frequency. Several tapered ground planes were proposed to improve the radiation pattern characteristics without degrading the impedance performance. A simulation result proposed a possibility of another antenna inventions providing 10:1 pattern bandwidth with the 10:1 impedance bandwidth. Research into wideband antennas demonstrated that the newly invented antennas are closely related each other and are evolved from a primitive element, PICA. Not only the comprehensive investigation but also a practical antenna design has been done for commercial base-station array antennas and to phased array antennas for government applications. This dissertation presents results of comprehensive investigation of new planar wideband antennas and its usefulness to the broadband wireless communications.
- Fourpoint antenna(United States Patent and Trademark Office, 2005-01-11)Wideband antennas with omnidirectional coverage have both military and commercial applications. In one embodiment, the Planar Inverted Cone Antenna (PICA) is composed of a single flat element vertically mounted above a ground plane. A geometry of Planar Inverted Cone Antenna (PICA) is based on the conventional circular-disc antenna with trimmed top part having the shape of a planar-inverted cone, in a second embodiment, the Fourpoint antenna also provides balanced impedance over the operating band and has useful radiation patterns and dual polarization over its operating frequency.
- Planar wideband antennas(United States Patent and Trademark Office, 2006-04-11)Wideband antennas with omnidirectional coverage have both military and commercial applications. In one embodiment, the Planar Inverted Cone Antenna (PICA) is composed of a single flat element vertically mounted above a ground plane. A geometry of Planar Inverted Cone Antenna (PICA) is based on the conventional circular-disc antenna with trimmed top part having the shape of a planar-inverted cone. in a second embodiment, the Fourpoint antenna also provides balanced impedance over the operating band and has useful radiation patterns and dual polarization over its operating frequency.
- Plug-and-play time-variant antenna module for wireless communication devices(United States Patent and Trademark Office, 2016-09-13)A plug-and-play antenna may be used with many different types of wireless communication devices. An antenna may be coupled to an impedance tuning component and a waveform generator. A calibration control module receives radio status information, controls the waveform generator to vary a response of the antenna, and tunes the impedance tuning component to match impedances between a radio and the antenna.
- A Propagation Simulator for Land Mobile Satellite CommunicationsSuh, Seong-Youp (Virginia Tech, 1998-04-24)The performance of a mobile satellite communications link can be determined by the propagation path between a satellite and mobile users. Some of the most important factors are multipath propagation and vegetative shadowing. System designers should have the most reliable information about the statistics of fade duration in order to determine fade margin or to compensate for the fades using modulation and coding scheme. This report describes a simulator, PROSIM, developed at Virginia Tech for simulating a propagation model in land mobile satellite communications. The simulator is based on a random number generator that generates data sets to compute statistics of the propagation channel. Performance of the simulator was evaluated by comparing statistics from an analytical model and experimental data provided by W. Vogel of Univ. of Texas at Austin and J. Goldhirsh of the Applied Physics Laboratory. New expressions for phasor plot and its mathematical expression for lognormal channel were derived and were simulated. Finally, the advantages of the simulator using random number generator in simulating the propagation model are described.
- Wireless communication device using time-variant antenna module(United States Patent and Trademark Office, 2017-07-11)Embodiments of the present disclosure describe methods, apparatuses, and systems related to a wireless communication device using time-variant antenna. Other embodiments may be described and/or claimed.
- Wireless communication device using time-variant antenna module(United States Patent and Trademark Office, 2018-07-31)Embodiments of the present disclosure describe methods, apparatuses, and systems related to a wireless communication device using time-variant antenna. Other embodiments may be described and/or claimed.
- Wireless communication device using time-variant antenna module(United States Patent and Trademark Office, 2016-05-24)Embodiments of the present disclosure describe methods, apparatuses, and systems related to a wireless communication device using time-variant antenna. Other embodiments may be described and/or claimed.