A highly-linear CMOS RF programmable-gain driver amplifier with a digital-step differential attenuator for RF transmitters

This paper presents a CMOS RF programmable-gain driver amplifier (RF PGDA) for wireless transmitters. Digital-step differential attenuators precede a programmable-gain amplifier in order to enhance the dynamic range and to save power consumption, especially at low gain region. The RF PGDA fabricated in 0.13-μm CMOS technology with a 1.2 V supply voltage achieves a dynamic range of 49 dB with a step error of less than 0.5 dB and highly-linearized output satisfying the WCDMA/LTE specifications.