Compact Low-Profile Tunable Metasurface-Enabled Antenna with Near-Arbitrary Polarization

The design and characterization of a compact, low-profile metasurface-enabled antenna with tunable frequency and polarization characteristics is reported. This antenna is made possible by a tunable artificial magnetic conducting (AMC) substrate combined with tunable crossed end-loaded dipoles. Intertwined miniaturized periodic unit cells comprise the AMC, presenting a homogeneous interface to the dipoles above. Moreover, the AMC structure is predominantly air, making it very lightweight. Tunable capacitors on the dipoles allow the dynamic reconfiguration of their input impedances, which in turn allows for near-arbitrary dynamic adjusting of the antenna's polarization for the left- or right-hand circular as well as linear with various orientations. Measurements of a prototype showed comparable performance with commercially available alternatives that were more than three times as thick as the new design reported here.