A self-healing two-stage millimeter-wave broadband power amplifier (PA) with on-chip amplitude/phase compensation is realized in 65-nm CMOS. The amplitude and phase compensations are accomplished by using feedback bias/capacitive schemes to extend the linear operation region and optimize the PA efficiency. Tunable control knobs are inserted in the linearization block to enhance the PA performance yield against process/temperature variations and device ageing effects. This prototype shows a 5.5-dB improvement of the output 1-dB compression point (P1dB) and a less than 2% chip-to-chip gain variation. At a 1-V supply, the differential PA achieves a saturation output power (Psat) of 14.85 dBm with a peak power-added-efficiency (PAE) of 16.2%. With the amplitude compensation, P1dB is increased to 13.7 dBm. With the phase compensation, the output phase variation is decreased to less than 0.5°. To the best of our knowledge, this prototype provides the highest Psat and P1dB with simultaneously high PAE from a single PA reported to date. The PA delivers a linear gain of 9.7 dB and has a 7-GHz 3-dB bandwidth from 55.5 to 62.5 GHz with a compact total area of 0.042 mm2.