A novel 180-degree 3 dB hybrid using a cylindrical cavity

This paper suggests a new type of 180-degree 3dB hybrid, which consists of a cylindrical cavity and four E-plane rectangular waveguides radially coupl ed with it, ard shows that good hybrid properties are realized by modifying the positions of the four input/output waveguides and the radius of the cy lindrical cavity that are determined by the field distribution of thp TE111 resonant mode. Moreover, a method of broadening the bandwidth with additio nal impedance steps is described. The present hybrid is marked by simple st ructure, and hence is useful for applications at millimeter wave frequencie s and to high-power microwave systems. Experimental verification is additio nally shown.