A Low-Profile Multi-Linear Polarization Reconfigurable Antenna with AMC Reflector

A new wideband multilinear polarization reconfigurable antenna with an artificial magnetic conductor (AMC) array reflector is proposed. The design features five pairs of elliptical dipole arms arranged on both the upper and lower surfaces of a substrate, connected to central feeding patches via PIN diodes. By selectively activating specific PIN diodes, the antenna achieves five linear polarization (LP) states at 36° intervals, ranging from 0° to 144°. A novel AMC unit is also introduced, consisting of a central pentagon surrounded by five arrow-shaped patches. By utilizing an AMC array as a reflector, a low profile of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$9 ~\text{mm}(0.145 \lambda_{h}$</tex> at 4.83 GHz) is achieved. The presented antenna offers an impedance bandwidth of 27.3 %, spanning from 3.67 GHz to 4.83 GHz, while delivering a peak gain of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{8.42~ d B i}$</tex> and cross-polarization below <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{- 3 0 ~ d B}$</tex>.