A 48-dB precise decibel linear programmable gain amplifier for GNSS receivers

A novel circuit architecture for programmable gain amplifier (PGA) is proposed, which simplifies and improves the conventional one and achieves wide precise digital decibel (dB)-linear gain control while obtaining a smaller gain error, smaller chip area and wider bandwidth with low power consumption. In the 0.18-μm CMOS process, the proposed PGA occupies less than 0.09mm² of chip area. From the measurements, the PGA shows a dB-linear gain range of 48 dB (−20 to 28 dB) with a gain error of less than 0.18 dB, a gain step of 0.86 dB, a maximum 1-dB compression point (IP1dB) of 10.4 dBm, and a 3-dB bandwidth of 450MHz at the maximum gain while consuming only 5.8mA from a 1.8-V supply.