An integrated SAW-less narrowband RF front-end

In this paper an integrated SAW-less narrowband RF front-end for direct conversion wireless receivers is presented. The analysis of the feedback system shows a shift of the center frequency fRX for the overall RF bandpass filter from its nominal value fLO. The proposed architecture incorporates a notch filter at 2fLO to insure that there is no shift in fRX. The design has been implemented in 65nm CMOS process. It consumes 44mA from a single 1.2V supply. Simulation results show a rejection of more than 15dB in a bandwidth of +/-500MHz around 2GHz due to the additional feedback loop. The theoretical and simulation results are in close agreement.