Computer aided design of two-stage amplifier for the frequency range 8 divided by 12 Ghz with MESFET and hybrid matching networks

It is shown that the lumped network design gives results more satisfactory than the distributed network design. Two amplifiers for optical telecommunication systems were designed: one with distributed matching networks, the other with lumped networks. The first design method did not give satisfactory results for the bandwidth (1 GHz) and SWR (higher than 1. 5 all over the band). Therefore, the distributed amplifier was transformed by means of Richards' transformation into a lumped topology. Good results were obtained for the bandwidth (4 GHz) and the input and output SWR (smaller than 2 all over the band). Nevertheless, for high values of inductance and capacitance, which cannot be realized with lumped elements, the microstrip lines, whose characteristics have been determined by Schneider's method were used.