A Quasioptical Directional Coupler on Diffraction-Coupled Transmission Lines

摘要

A circuit and principle of operation of directional couplers based on diffraction-coupled transmission lines, the emitting apertures of which are formed from periodic structures and dielectric waveguides, are described. The experimental studies of the coupler prototype in a 30- to 37-GHz band have shown that the coupling on spatial waves allows one to obtain transient attenuation values in a 3- to 20-dB interval at a ～30-dB directivity, this being roughly in conformity with similar characteristics of a coupler on dielectric waveguides. The main advantage of the described directional coupler is that it is possible to correct its characteristics over wide ranges by changing the distance between the emitting apertures.