A 49-81 GHz Power Amplifier with a Four-Coupled-Line Achieving 4.04THz GBW and 19.57% peak PAE

This paper employs a Four-Coupled-Line(FCL) matching structure according to theoretical framework for impedance matching and gain complementarity enhancement using coupled-line techniques. It innovatively incorporates the bulk into the impedance matching network, taking into account the comprehensive impact of the gate, source, and bulk on impedance matching. Utilizing a 65nm CMOS process and a three-stage common source structure, the work achieves a gain of 21.01 dB and a peak power-added- efficiency (PAE) of 19.57% for a power amplifier(PA) within the frequency range of 49 GHz to 81 GHz. The core area of the proposed PA is 0.056 mm². Additionally, source capacitor techniques, misaligned frequency point technology and FCL are employed in achieving broadband functionality.