Common emitter and cascode topologies at G band: A comparative study on a single stage 183 GHz power amplifier

At mm-wave and sub-Thz frequencies, the power amplifier gain, and output power are limited due to high conductor losses. The selection of a topology for the design of power amplifier (PA) becomes questionable due to small gain. Therefore, this paper presents the design of single stage power amplifier at 183 GHz using common emitter (CE) and Cascode topology. The two topologies are contrasting in terms of maximum available gain, stability factor, optimum impedances, output power, and efficiency. From the full EM simulation, we found that CE topology is less sensitive to interconnects in comparison to Cascode topology. In addition, CE PA provides better output power, and efficiency than Cascode PA. However, the gain of CE PA is very small in comparison to Cascode PA which makes it non-suitable for sub-THz power amplifier design.