A CMOS Multisegmented Bias Circuit for Temperature Variation Compensation of RF Amplifier

This paper presents two kinds of bias circuit structures, including multisegmented reference current bias network based on current mirror control, and multisegmented reference current bias network based on hysteresis comparator and multiplexer selector control. Both of them are composed of PTAT current sources, CTAT current sources and other control circuits to accomplish proportional control, current segmentation and current superposition. This method can flexibly compensate for temperature changes of various complex types of RF amplifiers. Designed in SMIC 0.18 μm CMOS technology, simulation results show that the proposed CMOS temperature compensating bias circuit can effectively compensate cascode RF amplifier. The gain change rate of the cascode structure amplifier decreases to 1.37% over the temperature range from 20 ℃ to 85 ℃.