Design techniques for loss mitigation in metamaterial reflector antennas

There are often discrepancies between the behavior of a metamaterial reflector unit cell in an infinitely periodic environment and in a non-ideal environment in which the reflection phase varies across a metamaterial reflector. This work considers the performance of several capacitively loaded metamaterial unit cells in order to improve the realized gain of a reflector antenna. Each structure exploits capacitive elements to achieve a desired reflection phase gradient across the surface of the metamaterial reflector. The influence of interconnectedness and surface currents on the reflector antenna performance are analyzed and compared with the antenna performance from an ideal impedance surface reflector.