A W-band Class-F234 SiGe-HBT Power Amplifier with 35/19.7% Peak/PBO6dB PAE and 26% 1-dB Large-Signal Power Bandwidth

A high-efficiency W-band (75-110GHz) class-F
234
HBT power amplifier (PA) implemented in a 250/370-GHz $f_{T}/f_{\max}0.13-\mu m$ BiCMOS process is presented. The proposed class-F microstrip-based output matching network enables a concurrent synthesis of an optimal impedance (Z
opt
), even-harmonic $(2f_{0}/4f_{0})$ short, and odd-harmonic $(3f_{0})$ open that shape the collector voltage and current waveforms with reduced overlap, thereby enhancing the overall efficiency. At 89GHz, the PA achieves a PAE
peak
/PAE
PBO-6dB
of 35/19.7 % while delivering a P
SAT
/OP
1dB
of 10.2/9.5dBm with a >26% 1-dB large-signal power bandwidth (76-99 GHz). For a 1.6V supply, the measured peak power gain $(S_{21})$ is 11.5dB with a 3-dB small-signal bandwidth (76-103 GHz) covering almost the entire W-band. The PA shows no noticeable performance degradation after a 96-hour reliability test. To the authors’ knowledge, this is the first class-F SiGe PA with an excellent peak/PBO
6dB
PAE and largest 1-dB large-signal power bandwidth reported at W-band.