Synthesis of coupled resonator-based multiplexers with generalised structures using coupling matrix optimisation

Design techniques of coupled resonator circuits used in synthesising two port filters and three port diplexers are developed to synthesise N port multiplexers. Novel general structure is proposed and it can achieve an unlimited arbitrary number of channels, different responses and various properties and characteristics without extra resonators, external junctions or power distribution network in a compact size. The synthesis of the proposed multiplexers is based on optimisation approach where the coupling coefficients between resonators presented by coupling matrix are found from optimisation techniques by minimising a cost function.