Low Quiescent Current SiGe HBT Driver Amplifier Having P-MOSFET Current Mirror Type Self Bias Control Circuit

An L-band low quiescent current and low distortion SiGe HBT driver amplifier having a self base bias control circuit is described. Since the size of this circuit is small and it does not need external control circuit, it is easy to integrate with the driver amplifier on single chip. According to the output power level, the self base bias control circuit, which is the combination of a P-MOSFET current mirror and a conventional constant base coltage circuit, automatically controls the base voltage and allows low quiescent current at low output power level and low distortion at high output power level. The simulated result shows that the proposed driver amplifier realized P1dB improvement of 3.0dB compared with the conventional constant base voltage driver amplifier under the same quiescent current condition. The fabricated amplifier achieved P1dB of 14.9dBm with quiescent currrent of 15.3mA.