A 256MHz 60dB gain analog baseband chain with current-mode programmable gain amplifiers and low-pass filter

This paper presents a 256MHz analog baseband chain for Ultra-Wideband receiver in a 1.2V 0.13μm CMOS process. The test chip has an area of 0.79mm². The analog baseband chain is composed of current input and current output PGAs and filter to achieve wide bandwidth, wide gain range, good noise and linearity performance. The PGAs are carried out by a cascade of current amplifiers and the 6th order Gm-C filter is based on 6 double output OTAs. The V2I stage, TIA and buffer stage are added to connect with the mixer and ADC in the system respectively. The chip also includes analog DC-offset calibration circuits and a digital SPI circuit to generate gain control words. According to the post simulation results, the design has a gain range of 0~60dB, an IIP3 of -41dBm and 22dB noise figure at maximum gain mode. The chip consumes 38.4mA~46.4mA under supply of 1.2V at different gain settings.