Broadband Amplifier Design Technique by Dissipative Matching Networks

This work is focused on the design of broadband amplifiers by exploiting dissipative reciprocal matching networks. Unlike the classical approach, which makes use of lossless reciprocal matching networks, there is no need to trade-off the gain flatness with the input/output matching levels. In this contribution the flat gain condition is obtained partially by exploiting the mismatch loss at a certain section and partially by leveraging on ohmic losses. In particular, two different matching schemes have been analytically studied. Taking advantage of the more promising scheme of the two presented, the design of a linear power amplifier operating over the 4-40 GHz decade, is illustrated. The amplifier showed measured input/output return loss better than 9/10 dB respectively, a gain of 8 ± 0.6 dB and an output power level of 25.5 ± 0.5 dBm at 1 dB compression point. Incidentally, unconditional stability is obtained without considering additional stabilization networks or components devoted to the purpose.