This paper describes a Tx module for IMT2000 applications consisting of an up-conversion mixer and a variable-gain driver amplifier. The up-conversion mixer, based on the Gilbert active topology has a power gain of 4.8 dB and consumes 15-mA current from a 3-V supply. The variable-gain driver amplifier comprises a gain-controlled stage of the current steering structure and a common emitter stage, and has a variable-gain range of over 30 dB with 30.3-mA current consumption. The Tx module achieves a gain error of less than 1.2 dB over a 30-dB gain range, an output IP3 of 25 dBm, and an output PI dB of 7.4 dBm at the maximum gain of 24.5 dB. It occupies 1.0 × 1.2 mm.