A Wideband High-Gain Multilinear Polarization Reconfigurable Antenna

In this communication, a wideband low-profile antenna with switchable multilinear polarizations (MLPs) is proposed. An odd number of dipoles with trapezoidal-shaped arms printed on both sides of a substrate are adopted as reconfigurable radiators, which provides a much smaller polarization interval than using an adjacent even number of dipoles. The p-i-n diodes with simple dc biasing lines are loaded to reconfigure the polarization states. A circular-contoured artificial magnetic conductor (AMC) reflector using hexagon-patch cells is employed to reduce the antenna profile. The whole multiple dipole structure is rotationally invariant, which provides almost rotationally invariant antenna performance for different LPs. In addition, the antenna can be easily redesigned when adjusting the number of dipoles for different LPs. A seven-LP reconfigurable antenna working in 2.85-3.40 GHz is used as an example to give the detailed parameters' study and performance analysis. Three antennas with five, seven, and nine reconfigurable LPs are designed and measured. With 0.035λ height, they achieve the measured overlapped bandwidths of 20.6%, 17.6%, and 15.9% for five, seven, and nine LPs, respectively, and their measured peak gains are ranging from 8.3 to 8.5 dBi.