An HBT MMIC power amplifier with an integrated diode linearizer forlow-voltage portable phone applications

摘要

This paper gives a detailed description of a novel linearizationntechnique using a transistor base-collector junction diode. The novelnlinearization technique effectively improves the gain compression andnphase distortion of the heterojunction bipolar transistor (HBT) with nonadditional dc consumption, leading to highly efficient linearnamplification of the Π/4 DQPSK modulation signals. An AlGaAs/GaAs HBTnmonolithic microwave integrated circuit (MMIC) linear power amplifiernwas fabricated using the novel linearization technique for the handsetsnused in the 1.9 GHz Japanese Personal Handy Phone System (PHS). Thenfabricated HBT MMIC power amplifier exhibits an output power of 21 dBmnand a power-added efficiency as high as 37% at an operation voltage ofn2.7 V. At this rated output power, the adjacent channel power rejectionnin ±600 kHz offset frequency bands is -55 dBc and the errornvector magnitude is 4.3%. This measured linearity is well within the PHSnstandard