A novel filtering function for linear phase dual mode filters with nonequi-ripple

This letter describes a novel filtering function for linear phase dual mode filters with nonequi-ripple. Filter selectivity is easily adjusted to provide higher level near the band edges by the redistribution of the reflection zeros in the passband in relation with the location of the transmission zeros in the stopbands. Proposed filtering function has attractiveness because of its fast and simply applicability to exact and approximate synthesis techniques described in microwave literature and can also be used for the form with nonequi-ripple of the other filter types such as canonical filters, cross-coupled filters and source/load coupled filters. The theoretical design examples and simulated filter responses are presented for even degree filters.