Design of a Programmable Gain Amplifier with High Accuracy for UHF RFID Transmitters

Utilizing a standard 0.18 μm CMOS process, a programmable gain amplifier (PGA) with high accuracy is designed for UHF RFID transmitters. This PGA is connected by the fine tuning stage and the coarse tuning stage. A close-loop resistor feedback structure is used in the fine tuning stage, which achieves a fine gain control and improves the linearity. An open-loop source negative feedback structure is adopted in the coarse tuning stage, which realizes a coarse gain control and reduces the power consumption. The simulation results show that from a supply voltage of 1.8 V, the PGA has a power consumption of 2.69 mW, a dynamic range of -12~24 dB by 1 dB step with a gain error less than 0.02 dB, and a input 1 dB compression of -5.54 dBm at the gain of -12 dB.