Design of A Modulated Wideband Converter for Low-Speed Sampling of Sparse Analog Signals

The modulated wideband converter (MWC) is a sampling system that realizes the sub-Nyquist sampling rate by using the compressed sensing (CS) theory. This paper presents an analog front-end circuit for a modulated wideband converter, which consists of four channels. Each channel is composed of a mixer and a low-pass filter. The mixer adopts a passive structure, which can achieve a higher degree of linearity compared with the traditional Gilbert structure. The filter adopts a GM-C structure, which can consume lower and easily achieve higher operating frequency compared with the traditional RC structure. In this paper, the smic180nm CMOS process is used for simulation verification. The front-end circuit can process input signals from DC to 1GHz, and the reconstruction of dual-band signals with a maximum frequency of 200MHz is verified. The normalized mean square error (NMSE) is less than -20dB.