E-band Downlink GaN PA with a Homogeneous Output Power of 2.7W and a Peak PAE of 32.3%

A highly homogeneous, high efficiency, multi-watt output power E-band downlink (71-76 GHz) Gallium Nitride (GaN) power amplifier (PA) is presented in this article. The 4-stage PA has been measured with an output power of 33.5 +/- 0.8dBm (2.28 +/- 0.42 W) across the 68-76GHz frequency range. The peak power-added-efficiency (PAE) of 32.3% is measured at 69 GHz, with an associated output power of 34.3dBm (2.7 W) and a power gain of 22.3 dB. The peak PAE variation across the 31 working cells (out of 37 cells) measured on-wafer is less than 2.5%-points, which demonstrates the design's homogeneity. These results are made possible by excellent in-house wafer processing, utilizing the new microstrip line (MSL) transistor models, and implementing the core matching networks with two-section transmission lines, which are also designed to have a low insertion loss. To the best of the authors' knowledge, the peak PAE and power gain reported in this work are the highest for a multi-watt level PA published in the literature at E-band (60-90 GHz).