A CMOS wideband front-end chip using direct RF sampling mixer with embedded discrete-time filtering

A CMOS wideband front-end IC is demonstrated in this paper. It consists of a low noise transcon-ductance amplifier (LNTA) and a direct RF sampling mixer (DSM) with embedded programmable discrete-time filtering. The LNTA has the features of 0.5-6 GHz wideband, wideband input matching and low noise. The embedded filter following the DSM operates in discrete-time charge domain, filtering the aliasing signals and interferences while controlling the IF bandwidth according to the clock frequency. The measured NF of the front-end was below 7 dB throughout the whole band from 0.5 to 6 GHz. It shows a conversion gain of 12.6 dB and IP sub(1db) of--7.5 dBm at 2.4 GHz. It occupies a chip area of 0.23 mm super(2) and consumes 14 mA DC current.