A Symmetrical Reconfigurable Multipolarization Circular Patch Antenna

A fully symmetrical six-polarization circular patch antenna is proposed. This antenna is coaxial-fed at center with 12 p-i-n diodes placed across a circular ring slot on the patch. By turning these p-i-n diodes on or off, six linear polarizations at a 30 degrees interval can be produced. Due to the circular symmetry, in theory all these polarizations share the same characteristics. A prototype operating at 2.4 GHz is designed and fabricated. The measured gains of these six polarizations are from 2.64 to 3.52 dBi. Simulated and measured results are in good agreement.