31.7 and 36.7 dBm Ka-Band SiGe BiCMOS Power Amplifiers Using Resonated Amplifier Cores and Optimized Power Combining

This paper presents $\mathbf{3 1. 7 ~ d B m}$ and $\mathbf{3 6. 7 ~ d B m}$ (4.7 W) $K_{\mathrm{a}}$-band power amplifiers (PAs) in a 130nm silicon germanium (SiGe) BiCMOS technology operating from a 3.5 V supply. High peak power-added efficiency (PAE) of $37 \%$ and $28 \%$ is achieved, respectively. This high output power and efficiency is enabled by refining a PA core design method for large device parallelization and optimized multi stage Wilkinson combiners. The PAs feature a single stage 4-to-1 and two stage 16-way power combiner with a simulated combining loss of only 0.64 and 1.3 dB, respectively. For a $400 \mathrm{MBd} 64-\mathrm{QAM}$ signal at an EVM $_{\text {RMS }}$ of −25 dB, the smaller PA delivers an average output power of 24.7 dBm with an average PAE of $10.6 \%$, while the larger version achieves 29.2 dBm at 7.1%.