Multilayer Minkowski Reflectarray Antenna With Improved Phase Performance

We propose a multilayer unit cell consisting of Minkowski fractal-shaped reflector with aperture coupled phasing stubs to obtain a broad phase range for reflectarray antenna with smaller unit cell size and interelement spacing compared with some other studies in the literature. In the study, simulations are conducted using high-frequency structure simulator (HFSS) program with Floquet Port incidence. A unit cell with two cycles of phase range and very low reflection loss is designed. About 21.9% shrinkage is achieved in patch surface area using Minkowski fractals. Subsequently, the proposed unit cell is used to design and fabricate a full-scale 221-element reflectarray antenna. At 10 GHz, the simulation results are compared with the measured data and a good agreement is observed.