A novel AGC scheme in a wideband receiver

Abstract

A new automatic gain control (AGC) scheme in a wideband wireless receiver is presented in this paper. The proposed AGC scheme consists a receiver architecture with tuning the gain of RF amplifier, mixer and IF amplifier synchronously, and a novel exponential function current generator to achieve dB-linear gain control characteristic. Fabricated on a 0.18um BiCMOS process, the proposed receiver provides a conversion gain dynamic range of 72 dB with the gain ripple of 5 dB that range from 0.8 to 2.7 GHz. At maximum gain operation, the noise figure of 9.9 dB and -25 dBm of third-order input intercept point are measured at 2.7 GHz. The chip draws 27 mW from a 1.8 V power supply and occupies an area of 2.8 mm².