Reflect-array study with shorted slotted ground plane using microtrip patches or rings as cell elements

Reflect-array antenna was introduced to replace parabolic reflectors, as they offer many advantages including beam steering, ease of fabrication, lightweight, etc.. The electromagnetic energy should reflect back when it hits the reflect-array surface. It has become very popular due to the advancement of printed antennas because of low surface profile, small mass and low cost. We have been studying microstrip rings as the cell element to obtain a reflect-array. When there is an aperture on the ground plane, the distance of the rings can be adjusted to obtain appropriate phases so that the electromagnetic energy can propagate through the ground plane or reflect back. The aperture size is another important parameter to obtain the reflection. When the aperture on the ground plane is partially shorted using a micrsotrip, the length of the aperture is essentially reduced, and the reflection from the structure can be achieved. In this paper, simulation results of the unit cell of a reflect-array are discussed, which is based on square rings with an aperture on the ground plane. The effects of the aperture size and the use of shorting strips are presented. The cell is in an infinite array environment. Simulations were carried out in Ansoft HFSS, version 12.