Application of dielectric resonator based metamaterial in waveguide coupler

Abstract

In this study an implementation of the metamaterial structure is used in a waveguide directional coupler. For this purpose a four-hole waveguide directional coupler in X-band is designed. Then the block of dielectric-resonator array is inserted between isolation port and holes of the coupler and the performances of the coupler with and without dielectric resonators are compared in terms of the coupling and isolation. The obtained results show that the coupler with dielectric resonators significantly improves the coupling and isolation performances at a new operation frequency band at which the traditional coupler does not work. Therefore the metamaterial structure attains multi-band characteristics to the coupler. Besides this new frequency band can be shifted by arranging the distance between the dielectric resonators and holes. Finally it is also observed that the bandwidth of the new frequency band can be increased by using more dielectric resonators in the array. © 2017 Elsevier B.V. All rights reserved.