Waveguide Quadruplet Diplexer for Multi-Beam Satellite Applications

The objective of this paper is to describe the design of an innovative and low-cost diplexer for Ka-band multi-beam satellite applications. The device is based on the use of two quadruplets to implement a number of transmission zeros (TZs) thus obtaining high-selectivity quasi-elliptic transfer functions. The resulting diplexer structure is particularly flexible in terms of layout, does not require tuning and has an excellent high-power behavior. In addition to theory, we compare the results of our simulations with the measurements obtained with a manufactured breadboard. The comparison shows excellent agreement thereby fully validating both the design procedure, and the new diplexer structure.