Optimum Synthesis of Inductorless Bandpass Filters Using a Combination of Identical RC Coupled Amplifiers

The feasibility of interconnecting many identical stages of low- low-gain band-pass amplifiers to constitute a high selectivity filter is studied. The mathematical problem of obtaining the narrowest bandwidth and the highest rejection ratio, for a given number of stages is formulated. A solution is given for two classes of networks where the optimum properties of Chebyshev polynomials are applicable. Examples for the optimum combination of band-pass stages, low-pass stages, and the output sensors of a semiconductor delay line are given.