A common power-stage cellular/PCS/W-CDMA triple-band MMIC power amplifier

This paper describes the design and experimental results of an InGaP/GaAs hetero-junction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) power amplifier for cellular (850 MHz)/PCS(1750 MHz)/W-CDMA (1950 MHz) triple-band mobile terminal applications. This two-stage power amplifier has only one power-stage in common for the triple bands to achieve a small chip and module size for low manufacturing cost. In order to reduce quiescent current for cellular band, the band selecting circuit to control bias current is used to the power-stage amplifier. This power amplifier has the power gain of 30 dB (26 dB, 25 dB) for cellular (PCS, W-CDMA) band and power-added efficiency (PAE) of 43% at the output of 28 dBm for cellular band under 3.4 V operation voltage.