40 W Ka-Band Single and Dual Output GaN MMIC Power Amplifiers on SiC

This paper presents single and dual output 40 W Ka-Band GaN MMIC PAs fabricated on $\mathbf{50} \ \mu \text{m}$ SiC using Qorvo's QGaN15 released process. The single output PA produces approximately 40 W of output power over the 27.5 - 29.5 GHz band and greater than 30W over the 26.5 - 31 GHz band with greater than 20 % PAE. A balanced PA architecture is selected resulting in return losses greater than 15 dB in fixture. The PA exhibits less than 0.3 dB power droop over a 5 ms pulse width. Design choices minimizing the performance degradation due to process variation are discussed. A dual output PA integrated with an input SPDT switch and output isolation circuitry is also detailed. This variant allowing the output signal to be routed to one of two selectable outputs without requiring large output switch devices is presented with preliminary measured results.