An 8-15 GHz CMOS Power Amplifier with a Compact Transformer-based Output Combiner

An integrated power amplifier using 65-nm CMOS bulk technology was presented in this work. The whole PA consists of a one-way drive stage and a two-way main stage. By employing a compactly designed transformer-based output combiner, the CMOS PA occupied a small core-area of $0.47\times 0.57mm^{2}$, and delivered 21.6 dBm of measured saturated output power at 10GHz, with a power added efficiency of 23.6%. The proposed PA can operate well in $8\sim 15GHz$ wideband.