Controlling Gain Enhancement Using a Reconfigurable Metasurface Layer

This paper presents a method to control gain enhancement of a microstrip antenna based on a reconfigurable metasurface layer. The proposed layer is maintained the antenna and consists of $5 \times 5 -$unit cells. The proposed unit cell is designed to has four PIN diodes for structure reconfiguration into states ON and OFF. Therefore, the layer may have many distribution patters of ON-OFF unit cells. Each certain distribution pattern can enhance antenna gain to a certain value. Four patterns of the layer are suggested to enhance the antenna gain of about 1 dBi to 2, 5, 8, and 11 dBi. An equivalent circuit is introduced to describe the performance of the proposed unit cell. Besides, full CST MWS simulations for the system are conducted. To experimentally verify the presented method, a prototype of the system is fabricated and partially tested. The measurements show a good agreement with simulations.