Metasurface-Loaded Tri-Mode Wideband Monopole Antenna using Characteristic Mode Analysis

Metasurfaces (MTSs) are often used for bandwidth enhancement of directional antennas. In this paper, an MTS-loaded tri-mode wideband monopole antenna is proposed, with an overall size of 0.52 x 0.52 lambda(2)(0) (where lambda(0) is the free-space wavelength at 2.22 GHz). Characteristic mode analysis (CMA) shows that the loading of MTS improves the magnitudes of modal weighting coefficients (vertical bar MWC vertical bar s) of the monopole, leading to trimode wideband radiation. The measured impedance bandwidth of the proposed antenna is 61.7% (2.22-4.2 GHz) for vertical bar S-11 vertical bar < -10 dB with omnidirectional radiation.