A 1.3V 26mW 3.2GS/s undersampled LC bandpass ΣΔ ADC for a SDR ISM-band receiver in 130nm CMOS

This paper presents the implementation of an undersampled LC bandpass SigmaDelta ADC with a raised-cosine feedback DAC. It directly converts after the LNA a signal centered in the ISM band at 2.442 GHz with a sampling frequency of 3.256 GHz. This circuit has been fabricated in a 130 nm CMOS process, it occupies an area of 0.27 mm² and is operating at a supply voltage of 1.3 V. The Signal-to-Noise and Distortion Ratios measured are 34 dB, 37dB and 42 dB for respective bandwidths of 25 MHz, 10 MHz and 1 MHz. The power consumption of the SigmaDelta ADC is 26 mW and its figure of merit is 2.3 pJ/bit.