Low profile superstrate using transformation optics for semicircular radiation pattern of antenna

In this article, a dielectric superstrate inspired from transformation optics is presented. When placed over a patch antenna, this superstrate increases the half power beam width (HPBW) of a classical patch antenna. An appropriate spatial transformation relation with spatial compression and refractive index shift factors has been used to derive an expression for a dielectric material profile. The wave front exiting from the transformed space is optimized for a semicylindrical shape. Then, a discretized version of this profile has been used to design a cuboidal superstrate. Full wave simulations have been presented that essentially show a superstrate device capable of producing a 297 degrees of HPBW in H-plane with a peak directivity of 3.2 dBi at the design frequency. The derived solution can be realized using the standard dielectric materials for real-world applications.