Design of Ultrawideband Digitizing Receivers for the VHF Low Band

The next generation of receivers for applications such as radio astronomy, spectrum surveillance, and frequency-adaptive cognitive radio will require the capability to digitize very large bandwidths in the VHF low band (30 to 100 MHz). However, methodology for designing such a receiver is not well established. The difficulties of this design are numerous. There are various man-made interferers occupying this spectrum which can block desired signals or spectrum, either directly or through intermodulation. The receivers will typically use simple (i.e., narrowband) antennas, so the efficiency of power transfer to the preamplifier needs to be carefully considered. This thesis takes these design challenges into account and produces a seven step design methodology for direct sampling wideband digitizing receivers. The methodology is then demonstrated by example for three representative receivers. Finally, improvements to the analysis are suggested.