Ultra-Wideband RF Front-end

Abstract

The goal of this thesis was to design a new RF front-end receiver for a ground penetrating radar, with a bandwidth of 4 GHz and the implementation of range-gate switching. Several manufacturers were considered in the quest for suitable components, and the most interesting components were ordered for testing. From these results, two different receiver designs were prototyped and further developed, and several measurements were conducted to determine if they fulfilled the desirable specifications. Only one of the designs proved to yield the desired gain characteristics, with a total gain of around 55 dB, and a small gain variation across the desired bandwidth. The initial design had issues regarding oscillations because of feedback in the DC network, and had to be sorted out to achieve the final results. The dynamic range of this design was calculated to be approximately 108 dB, with a 1 dB compression point at around 18 dBm. The video leakage transients from the range-gate switches, and the T/R leakage, did not saturate any of the amplifiers in the receiver. However, there is always room for further improvements of the design, which has been discussed in the thesis.