High-Linearity Two-Watt Power Amplifier Design in Indium Gallium Phosphide/Gallium Arsenide HBT Process for Multi-Band Wireless Applications.

摘要

Amplifiers in the final stages of wireless transmitters boost the power level of the up-converted signals. Unfortunately, the ultimate power level is not the same for all transmitters. This same amplifier can be used as a driver in cellular base stations or as the last stage in pico-cells. However, the amplifier has to meet the stringent linearity requirement imposed by different standards. This work presents a high-linearity two-watt power amplifier in InGaP/GaAs HBT process. The amplifier is externally matched in any band of interest between 400 MHz and 2700 MHz. The design includes a novel circuit to minimize the third order intermodulation distortion component and thus improves the linearity of power amplifiers. The circuit utilizes the base-collector and base-emitter diode capacitances of a transistor biased in the saturation region to provide a nonlinear feedback path between the output and input of the amplifier.