Amazing Effect of Serpentine-Shaped Taper in Designing Planar Dielectric Waveguide Branch Circuits

A new method is proposed for designing planar dielectric-waveguide branch circuits with a high performance. This method intentionally generates the radiation wave locally on a circuit, and well controls its behavior to have desired power conversion and reconversion between surface-wave modes and the radiation wave, thereby realizing a necessary branching characteristic. The effectiveness of our idea is confirmed by synthesizing both high performance Y-branch and hybrid 3dB coupler and also with some measurements that we took.