Ka-Band GaN Power Amplifier with Integrated DC Supply Switch and RF Switch

This work presents power amplifiers with integrated features like DC supply switch for reducing the power consumption in receive mode of an RF front end (RFFE) module and RF switch for compact RFFE module design. Two $28-32 \mathrm{GHz}$ power amplifiers, one with only DC supply switch and the other with both DC supply switch and RF SPST switch, are designed and fabricated using $0.15 \mu \mathrm{m}$ GaN-on-SiC technology. The PA with DC supply switch shows a measured small-signal gain of $11-12.7 \mathrm{~dB}$ at $28-32 \mathrm{GHz}, P_{\text {sat }}$ of 31 dBm and PAE $_{\text {peak }}$ of $24 \%$ at 30 GHz. The PA with DC supply switch and RF SPST switch, on the other hand, exhibits a measured small-signal gain of 9.2 11.6 dB at $28-32 \mathrm{GHz}, P_{\text {sat }}$ of 29.5 dBm and PAE $_{\text {peak }}$ of $15 \%$ at 30 GHz. In the receive mode, the measurements show a power consumption of only 20 mW (instead of 2 W in transmit mode) port-to-port isolation of more than -27 dB and $S_{22}$ higher than -3 dB at $28-32 \mathrm{GHz}$ highlighting the effectiveness of integrated DC and RF switch.