A matched filter design by charge-domain operations

Abstract

This paper describes a novel matched filter (MF) design and its basic operations. The MF is based on the charge-domain operations that have a very simple structure compared to ordinary designs. To investigate the charge transfer characteristics and operations of correlator circuits that compose the MF, prototype designs are made by standard CMOS and fabricated by MOSIS 1.5 u, double overlapping poly, and double metal technology. The power consumption of the fabricated design was 7.0 pJ/Sample/tap. This value should be 1/10 of that of the current state of the art switched capacitor MF design, given that the same process technology was applied to both. Circuit area was 0.151 mm2/tap and this is also 1/2 of that of switched capacitor designs of the same technology. The correlator circuit of the new MF is composed of several steps of charge transfer operations. Hence, no special fabrication process such as those used for CCD imager is required. The detailed structure and operation of the correlator is explained.