A Low-Profile Wideband Pattern-Reconfigurable Metamaterial Antenna Based on Higher-Order Modes

In this letter, a low-profile wideband pattern-reconfigurable antenna is proposed. The antenna is designed for indoor 5G communication scenarios. The beams can be reconfigured in four tilted directions and one broadside direction. The novelty of this work is that the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{T}}{{{\text{M}}}_{22}}$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{T}}{{{\text{M}}}_{20}}$</tex-math></inline-formula> modes in a metamaterial resonator are tuned together by eight tuning pins, so that a wideband odd-even-mode superposition can be realized, and the antenna can realize wideband tilted beams. The electromagnetic (EM) simulation indicates that the broadside beams have an impedance bandwidth (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{\bm{S}}}_{11}}$</tex-math></inline-formula>< −10 dB) of 3.25 GHz to 3.90 GHz, while the tilted beams have an impedance bandwidth from 3.2 GHz to 4.25 GHz, and in frequency band 3.2 GHz to 4 GHz, a tilted beam about 30° can be observed, the front-to-back ratio in θ = 30° plane is also higher than 7 dB. Finally, a sample antenna is fabricated and tested to verify the simulation.