A Novel CMOS Constant-Bandwidth Variable-Gain Amplifier for WiMAX Receivers

In this study, a novel variable-gain amplifier (VGA) is proposed. A mathematical analysis of the circuit is given. The proposed circuit keeps a constant current flowing through the load transistors and provides a constant bandwidth over the voltage gain range. The circuit is designed with TSMC 180 nm CMOS technology, using 1.8 V single supply voltage and simulated with Cadence Analog Virtuoso.