Computer Aided Design of Broadband Matching and Coupling Structures

A new principle of Broadband Matching Network in Transmission Line Circuits is described which can be used for transformer, coupler and other multistructure applications. In this new design, the distance between succeeding impedance steps or coupling holes is much smaller than a quarter of a wavelength. This results in a greater number of steps or holes and lower single step reflections for a given coupling function or overall impedance transform ratio. The performance is therefore considerably improved. As an illustrative example, a waveguide directional coupler using the new network principle is shown. This technique can also be used for the development of very wide bandwidth (10:1) components.