Probe-fed broadband low-profile metasurface antennas using characteristic mode analysis

A probe-fed metasurface antenna utilizing three characteristic modes is proposed for low-profile and broadband operation with reduced back radiation. The antenna is designed with the aid of characteristic mode analysis (CMA) of the metasurface comprised of multiple metallic patches. The CMA results indicate that three modes of the proposed metasurface are simultaneously excited for bandwidth enhancement, being a slot mode, an extraordinary TMe30 mode and an ordinary TMo30 mode, all with broadside radiation patterns. The prototype (λ
₀
×λ
₀
×0.05λ
₀
at 5.5 GHz) is exemplified at 5-GHz Wi-Fi bands, showing a 36% 10-dB impedance bandwidth with 6-10 dBi boresight gain.