Analytical characterization of the step discontinuity between a circular and an offset coaxial waveguide using the mode matching technique

Summary form only given. The circular and coaxial waveguide discontinuities were and still remain of great importance in the development of microwave networks. This is due to the fact that multiple discontinuities of these types can be used in the analysis of offset single or multiple coaxial irises in a circular waveguide. This basic geometry can be used in the design of high quality microwave networks like filters, impedance transformers and horn antennas. The offset coaxial iris requires the study of the discontinuity of a circular-to-an offset coaxial waveguide. This is exactly the purpose of the present work. It is important to note that this approach offers the possibility of the introduction of multiple offset coaxial irises on a single diaphragm. In turn this is expected to yield more compact microwave components. The analytical evaluation of the involved coupling integrals results in a very fast and accurate method that makes it appropriate to be included within microwave network synthesis algorithms. A number of geometries have been studied, including single and double offset coaxial irises. Some of them are presented for comparisons with commercial electromagnetic simulators in order to validate the proposed analytical formulation.