Design of Ring-Manifold Microwave Multiplexers

A ring manifold for connecting microstrip bandpass channel filters to form a multiplexer has been developed. A method of connecting the bandpass filters to the ring has been devised, all ports are well matched in their passband, and highly isolated. By modifying the length of the feed lines which connect the filters to the ring, it has been shown that the filters can be connected to the ring to form a multiplexer without significant interaction. Experimental results for the multiplexer are given to verify the technique, and show good agreement with the simulated results