Quad-band GSM/GPRS/EDGE polar loop transmitter. - Tirdad Sowlati; Dmitriy Rozenblit; Rajasekhar Pullela; Morten Damgaard; Evan McCarthy; Dongsoo Koh; David Ripley; Florinel Balteanu; Ionel Gheorghe (IEEE J. Solid State Circuits, 2004)