A high-precision programmable gain amplifier in 0.18µm CMOS technology

A high-precision programmable gain amplifier (PGA) for ultra high frequency radio frequency identification (UHF RFID) readers is designed in standard 0.18μm CMOS technology. For the purpose of a good tradeoff between linearity and power consumption, a close-loop resistive-feedback technique is employed in the former to achieve a fine gain control and improve the linearity and an open-loop source negative-feedback technique is adopted in the latter to realize a coarse gain control and a power reduction. Sophisticated biasing techniques are implemented to prevent the gain resolution of PGA being affected from pressure-volume-temperature (PVT) variations. Simulations results exhibit that the PGA operates reliably at all process corners and can be tuned from 0 dB to 48 dB with 1 dB step, achieves a gain error of less than 0.016dB and consumes 4.65mW from a single 1.8V power supply.