A high efficient dual path power amplifier for IS-95 CDMA handset applications

A highly efficient dual path power amplifier (PA) for IS-95 code division multiple access (CDMA) handset applications is proposed. A dual path PA consists of two different size PAs combined parallely with single input/output matching circuits. The dual path PA operates in two different modes, a high power mode and a low power mode (lower than 16 dBm). A dual path PA is fabricated in an InGaP/GaAs heterojunction bipolar transistor (HBT) monolithic micro-wave integrated circuit (MMIC) for the 1.76 GHz Korea Personal Communication Service (K-PCS), and operates at a supply voltage of 3.4 V. The dual path PA exhibits an output power of 29 dBm, a 46 % power added efficiency (PAE) at 28 dBm output power, and a -39 dBc adjacent channel power ratio (ACPR) at a 1.25 MHz offset frequency in the high power mode and an output power of 24 dBm, a 19 % PAE at a 16 dBm output power level, and a -58 dBc ACPR at a 1.25 MHz offset frequency in the low power mode.