Novel concept for low-loss modular channel branching filters

Low-loss and low-priced channel branching filters are of great interest e.g. for radio relay systems and cellular radio base stations. The paper describes a novel concept for modularly constructed waveguide multiplexers of manifold type to assure the expansion or reduction of an already existing multiplexer by a predetermined number of channel filters - during system operation. Furthermore high-selection dielectric-resonator-filters guarantee good climate conditions as well as low passband loss, symmetric attenuation skirts and attenuation poles at finite frequencies. All the measured results are in good correspondence with theory and confirm the applicability of the novel concept.