Reconfigurable Fresnel Lens Based on an Active Second-order Bandpass Frequency Selective Surface

In this communication, we experimentally demonstrate a frequency- and beam-reconfigurable lens antenna based on an active second-order bandpass frequency-selective surface (FSS). The FSS lens is composed of three nonresonant metallic layers separated by two thin dielectric substrates. By integrating microwave varactors in FSS unit cells, the center frequency of this bandpass FSS can be tuned from ...