Antenna Applications of Frequency- and Time-Domain Selective Devices

Recently, circuit loaded metasurfaces exhibiting different responses depending on the waveform of the incoming waves have been proposed. Here, we extend this approach presenting two different antenna applications. As a first example, we report an open-ended waveguide antenna capped with a band-pass filtering iris loaded with a lumped element circuit. Thanks to its peculiar frequency- and time-domain selectivity response the antenna exhibits different radiating patterns depending on the waveform of the transmitted/received signal. The same circuit is also exploited to design a mantle cloak able to hide an antenna to a pulsed radar system while keeping its radiation characteristics unaffected for a continuous-wave signal.