Analysis of a transition between rectangular and circular waveguides

An analysis is presented of a transition between rectangular and circular waveguides coupled by a rectangular slot in a metallic wall of finite thickness in the common transverse cross section. Expressions for VSWR (voltage standing-wave ratio) and admittance are obtained using a moment-method formulation with entire basis and testing functions. Numerical data on the variation of input VSWR with frequency are obtained, and a comparison between the theoretical and experimental results is presented. The variations in the values of minimum VSWR with change in slot dimensions are also studied. >