Flexible Programmable Gain Amplifier for Reconfigurable Direct-Conversion Receiver

This paper presents a flexible Programmable Gain Amplifier (PGA) with DC Offset Cancellation (DOC) for reconfigurable direct-conversion receiver. This circuit is designed for reconfiguration of GPS/Galileo and WCDMA dual mode receiver in order to reduce power consumption, because it consumes different current and provides different bandwidths in different working conditions. This PGA consists of one-stage variable gain amplifier and two-stage fixed gain amplifiers which uses closed-loop resistor-feedback circuit and DOC for each stage based on a DC negative feedback technique. Designed in TSMC 0.18 μm technology, this PGA provides a gain range from 0dB to 75dB and its power consumption is 1.087mA in 2MHz 3dB-bandwidth and 3.34mA in 12MHz 3dB-bandwidth.