CASCADE SYNTHESIS OF MONOLITHIC CRYSTAL FILTFRS POSSESSING FINITE TRANSMISSION ZEROS

A simple method for the synthesis of bandpass or bandstop filters possessing finite transmission zeros as a cascade of shunted double-resonator monolithic crystal filter (MCF) sections is given. The lowpass or highpass prototype transfer function is synthesized as a cascade of MCF prototype sections for which explicit expressions for the element values are given. Application of the narrow-band lowpass to bandpass frequency transformation to the prototype network then yields a physically realizable filter with the desired bandpass or bandstop response. An example of the synthesis of a bandstop filter is given to illustrate the approach.