Frequency Selective Surfaces and Their Applications for Nimble-Radiation Pattern Antennas

Two different active frequency selective screens are proposed to develop a new class of reconfigurable-agile radiation-pattern antennas. High frequency PIN-Diodes are precisely incorporated into the screens to reconfigure electromagnetic (EM) response of the surfaces imitating blocking-transparent window for the incident EM waves. The DC-feed loading in the first screen and the PIN-Diode parasitic effects are carefully examined to achieve the desired performance. The constraints of DC-feed lines for the first cylindrical screen are also clarified, and then a second surface is proposed to surmount them providing more functionality compared to the first one. The new structure is used to construct a nimble-radiation pattern antenna which introduces an agile configuration by sweeping the radiation pattern over all 360° azimuth angles. Furthermore, it is also able to reconfigure its radiation pattern to an omnidirectional state covering instantaneously the azimuth plane. Measurement and simulation results show that the proposed structures provide reconfigurable-agile radiation patterns over a minimum bandwidth of %10 in terms of matching and desired radiation pattern.