Wideband Differential Phase Shifters Using Waveguides Filled by Inhomogeneous Dielectrics

摘要

A new structure is proposed for wideband differential phase shifter. This structure utilizes a waveguide filed by a longitudinally inhomogeneous dielectric along with a simple uniform waveguide. To optimally design the structure, the electric permittivity function of the inhomogeneous waveguide is expanded in a truncated Fourier series, firstly. Then, the optimum values of the coefficients of the series are obtained through an optimization approach to have low phase shift error and low reflection coefficient in a desired frequency bandwidth. The usefulness of the proposed structure is studied using some examples in the X-Band.