Phase quantized quasi-Sierpinski carpet reflector for OAM beam generation

This work proposes a quasi-Sierpinski carpet type reflecting surface. The reflector incorporates remodeled Jerusalem type sub-wavelength elements. The element arrangement ensures a 3-bit phase quantized encoding for the reflected beam. Microstrip antenna feed illuminates this reflector. We start with EM simulation of a broadband unit-cell reflector. We assume that the final reflector based on such unit-cell shall show broadband characteristic. The simulated beam from the reflector, due to spatial arrangements of the unit-cells, showed the fundamental mode of orbital angular momentum vortex beams. Experimental verification of fabricated prototype shows good agreement with simulated far-field results at 9.5 GHz, 10 GHz, 10.5 GHz, and 11 GHz which indicate a broadband characteristic.