A new form of hybrid junction for microwave frequencies

The principle of the branch-waveguide directional coupler has been applied to the design of a new form of hybrid junction for microwave frequencies. An equal division of power between the main and subsidiary waveguides is achieved by arranging the voltage coupling coefficients of the branch waveguides in accordance with the coefficients in a binomial expansion. Details of design and performance of such a hybrid junction are given for the 3 cm waveband. Its properties are superior to those of the hybrid-T and rat-race and compare favourably with those of the short-slot hybrid. In addition, the geometrical configuration of this form of hybrid junction is convenient for the construction of compact waveguide circuits.