Computer-aided optimal synthesis of bandpass filters

A method is developed for the computer-aided synthesis of a particular case of linear, lumped, passive, bilateral, lossless bandpass ladder filters. It involves the numerical values of the open-circuit immittance functions in three sets of equations referred to as the terminal, the remainder, and the junction algorithms. The filter model comprises two chains of LC sections, each of which contains one arbitrary component value and a finite frequency rejection circuit. The response of this model is exact, save for roundoff errors. The possibility of placing boundary values on all component values is then investigated through a systematic permutation of all finite frequency rejection circuits and by varying all arbitrary component values in a programmable number of steps. The process is applied to the example case design of a 70-MHz 14th-order filter.