Asymmetric Realisations for Dual-Mode Bandpass Filters

Two realisations are discussed for dual mode inline bandpass microwave filters which have asymmetrically-valued couplings about the physical centre of the filter. Advantages are gained in the first type of realisation which has no realisability conditions on the pattern of the transmission zeros in the complex-plane representation of the transfer function, and in the second which needs less coupling elements.