A fully integrated dual band GSM/DCS direct conversion transmitter

This paper describes the design and implementation of a dual band GSM/DCS direct conversion transmitter. The chip is implemented in a 0.8 /spl mu/m SiGe BiCMOS process with ft of 35 GHz. The 3.1/spl times/1.9 mm/sup 2/ chip is packaged in a TQFP44 ceramic package and operates at a supply voltage of 2.7-3.3 V. The transmitter delivers an output power up to 7 dBm to a 50 /spl Omega/ load. An LO leakage of less than -40 dBc, an image rejection ratio in excess of 50 dBc and harmonic suppression of more than 50 dBc are achieved. The transmitter IC consumes 33 mA in each of the GSM or the DCS band from 3V power supply.