New design approach for high-order recursive filter using MMIC technology

A new design approach for high-order active recursive filters is presented in this paper. The methodology is based upon a multi-cellular approach. Transfer functions of such filters result from a cascade association of unitary transfer functions. Consequently, the synthesis can be more easily performed. We illustrate our approach with the physical implementation of a composite four-cell active bandpass recursive filter, in the X-band with 5 dB gain and ¿40 dB out-of-band rejection. This filter results from the cascade association of four MMIC first order active recursive tunable filters.