A CMOS 65nm 120 dB Stacked A/D converters receiver for long wavelength radio astronomy observations

This paper presents a 120 dB Stacked analog to digital (A/D) converter dedicated for radio astronomy. The design of the chain of cascaded amplifiers preceding the A/D converters was performed in a 1.2 V 65 nm CMOS process. Simulation results showed that the designed chain of three cascaded amplifiers has an overall gain of 90 dB (30 dB each) over 100 MHz of bandwidth. The paper proposes also a calibration technique that copes with the phase and gain mismatches between channels allowing thereby to reach the minimum required SNR of 30 dB over all the input range.