This paper presents a 60-GHz power amplifier with on-chip varactor-based tunable load-matching networks and an embedded DC temperature-sensor-based power detector. The output power can be monitored by the DC temperature sensor, and loadmatching network can be tuned by regulating the control voltage of the varactors, which can be used for correcting unpredictable process, supply voltage, and temperature (PVT) variations and load mismatch. Measured results show that the small-signal gain of the CMOS power amplifier is up to 6.5 dB at 52 GHz. The power amplifier achieves 5 dBm output P1dB and 7 dBm saturated output power with 4.5% maximun power added efficiency (PAE) at 1 V control voltage. By sweeping the control voltage of the varactors, the power amplifier can obtain the maximun power gain, which can be used to solve the load mismatch.