超宽带功放MIC R AVE JOU OW REVIEWED TECHNICAL FEATURE IT OR IAL B O R A D AL RN ED COMPUTER-AIDED DESIGN OF ULTRABROADBAND 100 MHZ TO 20 GHZ AMPLIFIERS Computer-aided design (CAD) and performance of ultrabroadband 100 MHz to 20 GHz feedback amplifiers are presented. The amplifiers employ pseudomorphic high electron mobility transistors (pHEMT) and exhibit excellent agreement between predicted and measured results. The concept of negative resistive feedback was used for the design and provides the required ultrabroadband performance with low terminal input and output SWRs as well as good gain flatness. The design approach was verified using a single-stage feedback amplifier and a multistage feedback amplifier. The single-stage 100 MHz to 20 GHz amplifier achieved a gain level of 8 ±1 dB, i……