Quad-polarization reconfigurable antenna with wideband operation

A design for quad-polarization-agile antenna is described. A multiport crossed dipole that can provide dual orthogonal linear polarizations is used as the radiating element of the design. When the crossed dipole is fed with a tunable power divider, the two linear polarization radiations can be simultaneously excited with same amplitudes and difference phases. The resultant polarization modes include ±45° linear polarizations, right-handed circular polarization, and left-handed circular polarization. The overlapped operation bandwidth of the four polarization modes is about 49%, and the antenna operating in each polarization mode has almost the same radiation patterns. These patterns are also stable against frequency. Moreover, the occupied area of the polarization reconfigurable antenna is about 0.43λ₀ × 0.43λ₀.