A Wideband Widebeam Low-Profile Patch Antenna Based on Non-Uniform Metasurface Structure

In this work, a wideband low-profile patch antenna with widebeam feature by using a non-uniform metasurface (MS) structure is proposed. The proposed antenna is composed of a patch antenna fed by a pair of differential probes and a non-uniform metasurface structure as a ground plane. By properly changing the sizes of metasurface unit cells, the reflection phase of these unit cells can be adjusted to optimize the surface current distribution on the metasurface structure. Accordingly, the beamwidth of the patch antenna can be enlarged noticeably, especially at the high frequency band. Compared with the patch antenna using uniform metasurface structure, the proposed antenna exhibits a much larger beamwidth on E-plane, especially at high frequencies. Finally, the simulated results indicate that the bandwidth can be realized within a range of 5.8 to 7.5 GHz <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(24.77 \%)$</tex>, and the half-power beamwidth (HPBW) of the proposed patch antenna on E-plane can be enlarged from 81.88° to 187.5° at 7.4 GHz. Therefore, the proposed patch antenna with widebeam feature would be a promising potential application in wide-angle scanning phased array.