A 1.8-V monolithic SiGe HBT power amplifier with a novel proposed linearizing bias circuit

In this work, we report a linearization technique by using an on-chip linearizer. The linearizer consists of a SiGe heterojunction bipolar transistors active bias circuit with a MOSFET feedback junction capacitor, which significantly improves the gain compression and phase distortion without additional dc consumption. The proposed circuit topology finds extensive applications in high efficiency and linearity power amplifier design. The power amplifier is implemented by using TSMC 0.18 /spl mu/m SiGe HBT technology. The compact VBIC model of SiGe HBT was successfully established for the circuit design, and then a 2 GHz power amplifier was designed for demonstrating the circuit performances. The HBT power amplifier exhibits an output power over 20 dBm with a power-added efficiency higher than 42.4% under 1.8 volt operation.