A CMOS E/W-Band Power Amplifier with 53% Bandwidth Using an Over-Neutralized Active Core for Dielectric Waveguide Interconnects

This paper presents an ultra-wideband two-stage power amplifier covering the E- to W-band for high-speed dielectric waveguide interconnects. The power amplifier employs an over-neutralized active core for improved gain, and multi-section impedance matching networks to achieve wider bandwidth. A cascode device with an inductive inter-stage compensation network is adopted to mitigate potential stability issues. The prototype power amplifier implemented in a 28-nm bulk CMOS process achieves a record S21 3-dB bandwidth of 53% (63.9-110 GHz), among CMOS E/W-band power amplifiers, exhibiting a peak gain of 15.5 dB. Continuous-wave measurements demonstrate a saturated output power of 11.7 dBm, and a peak power-added-efficiency of 14.8%. The power amplifier core occupies 0.033 mm2.