A Silicon Germanium, High Efficiency Power Amplifier Chipset for GSM/DCS-PCS/WCDMA Handset Applications

A power amplifier chipset for GSM and WCDMA mobile handset PAs has been designed and fabricated in the IBM Silicon Germanium BiCMOS 5AM process. This 3-chip set offers competitive performance and reliability for integrated GSM/DCS-PCS/WCDMA applications. The constant envelope (GSM and DCS-PCS) power amplifier designs are optimized for efficiency under pulsed GMSK conditions, achieving 55% and 45% PAE at 900 and 1880 MHz, respectively, at 3.4 V. The linear (WCDMA) amplifier performance has been optimized for continuous HPSK operation with - 36dBc ACPR maximum with up to 27 dBm output power. This family of PAs relies on two biasing architectures to address pulsed and linear operation by effectively utilizing the broad library of devices available in the BiCMOS process. Power device design and thermal conductivity of the silicon substrate are such that reliable operating temperatures during multi-slot GSM and WCDMA operation are assured. ICs are assembled in low-cost, 50-ohm matched modules or 4mm leadless (QFN) packages.