Analysis and synthesis of passive coupled-switched-capacitor-resonator-based RF filters

摘要

Conventional radio-frequency filters, such as those realized using surface and bulk acoustic wave technologies, are continuous-time with well-known corresponding synthesis methods. Discrete-time continuous-value active filters, such as switched capacitor filters using operational amplifiers, are also well documented. In this paper, an analysis and synthesis of a special class of discrete-time continuous-value passive filters, namely, passive coupled-resonator switched-capacitor filters, are presented. Monolithic bandpass radio-frequency passive filters with high selectivity can be realized in commercial CMOS processes using this approach. These filters can be linear, low noise, compact, and tunable. Furthermore, the filter responses, including the number of properties of pass-bands and stop-bands, can be reconfigurable without significant performance degradation.