A filter synthesis technique applied to the design of multistage broadband microwave amplifiers

A synthesis method for designing multistage broadband amplifiers based upon well known filter synthesis techniques is presented. Common low-pass approximations are used to synthesize the amplifier circuit. A proof of concept Butterworth low-pass two-stage amplifier was designed, simulated and measured, and achieved a flat gain performance of 1-4 GHz with a gain of 15 /spl plusmn/ 1 dB as predicted. A comparison is made with the distributed amplifier (DA) and the cascaded single stage distributed amplifier (CSSDA). Theoretically a larger gain bandwidth product is achieved using the synthesis technique.