Wideband differential‐fed metasurface antenna array using characteristic mode analysis

Abstract A wideband differential‐fed (DF) metasurface (MTS) antenna array is proposed in this letter. As the element of array, a nonuniform MTS designed step by using characteristic mode analysis. In first step, 2 × rectangular patch‐based investigated. We observe that its two fundamental modes exhibit even/odd symmetric current distributions, which can be regarded as pair c/π modes. Unlike c mode, π features nonbroadside radiation, reshaped modifying to an asymmetric configuration second step. last direct DF method adopted excite and suppress other unwanted for performance. The optimal positions are quantitatively predicted calculating impendence bandwidth fed virtual probes. Moreover, further increase gain improve symmetry radiation patterns, elements integrated into linear array. Finally, fabricated measured. measured impedance 22.2% (6–7.5 GHz) with broadside stable gains varying from 8.5 11.3 dBi, front‐to‐back ratio better than 19 dB.