A load-insensitive quad-band GSM/EDGE SiGeC-bipolar power amplifier with a highly efficient low power mode

A load-insensitive fully-integrated quad- band GSM/EDGE radio frequency power amplifier for 824-915 MHz and 1710-1910 MHz has been realized in a 0.35-mum SiGeC-Bipolar technology. The chip integrates a low- and high-band 3-stage power amplifier including a bias-control circuit for power control, band select and mode as well as ramping dependent quiescent currents. The load-insensitive balanced PA architecture delivers for an adjusted output power of 34.5 dBm for all phases of a 3:1 VSWR a low deviation only 1.3 dB. At 3.5 V a saturated output power of 36.7 dBm is achieved at 870 MHz and 34 dBm at 1710 MHz. The respective peak PAE is 52% for low band and 42 % for high-band. The PA features a unique switched low power mode that involves disabling one half of each PA.