A novel CAD algorithm for corrugated harmonic rejection filters based on the synthesis procedures combined with the cutoff frequency correction method

A novel CAD algorithm using a modified synthesis procedure combined with the cutoff frequency correction method is presented for a fast and accurate design of corrugated harmonic rejection filters. The filter structures are analyzed by mode-matching formulation. Without an iteration or an optimization procedure, the proposed method resolves the proximity effect problem and gives a solution that is accurate enough for design of practical filters. The cutoff frequency correction factor is derived from the actual insertion loss for a pre-designed filter at the cutoff frequency only. Validity of the new method was confirmed by computer simulations and experimental measurements of the filter designed by this method.