Broadrange Reflectarray Element with Combined Slot and Dielectric Resonator Resonances

Anotace: This paper presents a dielectric resonator antenna (DRA) reflectarray unit element with multiple loading circular slots underneath in concentric form. The radii of the three slots are varied simultaneously to function as phase-shifting elements. For the case of three under-loading slots, it is very interesting to find out that the slot and DRA resonances can be pulled together to provide a very broad phase range of 916°. Study shows that the gradient and phase range of the S curve can be easily tuned by manipulating the dimensions of the under-loading slots. Waveguide method has been used to establish the simulation and measurement models. The reflection properties of the DRA unit elements loaded with different ring-shaped slots are compared, along with a complete parametric analysis. The proposed reflectarray unit element is very compact as its phase shifter can be entirely hidden beneath the DRA.