High-efficiency HBT MMIC linear power amplifier for L-band personal communications systems

A heterojunction bipolar transistor (HBT) MMIC linear power amplifier is demonstrated for the 1.9 GHz Japanese Personal Handy Phone utilizing the /spl pi//4 DQPSK modulation technique. At an operating voltage of only 3 V, an output power of 21 dBm and a power added efficiency of 35% are obtained along with a modulation vector error of 4.5% and an adjacent channel interference of /spl minus/60 dBc in +//spl minus/600 kHz offset frequency bands.<
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