A Multi-Band Low-Noise Transmitter With Digital Carrier Leakage Suppression and Linearity Enhancement

摘要

A low-noise multi-band transmitter for GSM quad-band and WCDMA is presented. Programmable parameters of the analog baseband and the RF frontend enable adaption for different protocols and frequency bands. A three-step carrier leakage calibration algorithm is proposed to suppress the leakage to $-$65 dBm at highest RF gain. Novel linearization methods are used in the low-pass filter and the driver power amplifier to meet the demand of 3G systems. The noise floor achieves $-$157 dBc/Hz at 190 MHz frequency offset in WCDMA band, which eliminates the need for external SAW filter.