A Nested-Reactance Feedback Power Amplifier for $Q$-Band Applications

A power amplifier (PA) topology is presented that incorporates a feedback network around the transistor to satisfy matching requirements. Circuit parameters can be tuned for small- and large-signal circuit operation. The PA is fabricated in a 120-nm SiGe BiCMOS process and performs from 36 to 41 GHz. The PA achieves a saturated output power of 23 dBm and a peak power-added efficiency of 20% at 38 GHz. This is the highest reported output power from a single PA at
Q
-band in silicon.