A K -Band CMOS Amplifier with Temperature Compensation for Gain Variation Reduction

This letter proposes a new temperature compensation method that automatically generates the adaptive bias voltage for a microwave amplifier to obtain nearly constant gain over a wide temperature range. The method uses a two-segment polyline to linearly fit the ideal bias curve, and each segment is realized through digitally controlled superposition of proportional-to-absolute temperature and constant-with-temperature currents. By applying the temperature compensation technique, the measured gain of a two-stage K-band amplifier fabricated in 90-nm CMOS technology varies by only 1.2 dB across an ultra-wide temperature range from -45 °C to +125 °C, corresponding to 0.35 dB/100 °C per stage, compared to 4.6 dB without any compensation. The chip occupies an area of 0.5 mm 2 and consumes 25.2 mW at 25 °C from a 1.2-V supply.