Polarisation-Reconfigurable Patch Antenna

A tunable hybrid coupler was successfully designed to feed an antenna for full polarisation capabilities. The proposed solution has the advantages of separating the active devices from the radiating element and thus avoiding any unwanted coupling effects. Also, it provides a full set of polarization states by simply changing the DC bias of both a SPDT and two varactor diodes. The feasibility of the concept was fully demonstrated and validated by S
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parameters and radiation pattern measurements