A 2.7-V GSM RF transceiver IC

A 2.7-V RF transceiver IC is intended for small, low-cost global system for mobile communications (GSM) handsets, This chip includes a quadrature modulator (QMOD) and an offset phase locked loop (OPLL) in the transmit path and a dual IF receiver that consists of a low noise amplifier (LNA) with an active-bias circuit, two Gilbert-cell mixers, a programmable gain linear amplifier (PGA), and a quadrature demodulator (QDEM), The TC also contains frequency dividers with a very high frequency voltage controlled oscillator (VHF-VCO) to simplify the receiver design, The system evaluation results are the phase error of 2.7 degrees rms and the noise transmitted in the GSM receiving band of -163 dBc/Hz for transmitters and the reference sensitivity of -105 dBm far receivers, Power-control functions are provided for independent transmit and receive operation, The IC is implemented by using bipolar technology with f(T) = 15 GHz, r(bb)' = 150 Omega, and 0.6-mu m features.