Design of High-Gain Metasurface Antenna Based on Characteristic Mode Analysis

A design method of the high-gain metasurface antenna based on characteristic mode analysis is proposed in this letter. The metasurface with uniform cells on the grounded dielectric substrate is used for controlling the modal significance of a specified characteristic mode. The metasurface containing two types of scatterers is investigated, and the interaction of the different scatterers has a significant impact on the eigenvalues of characteristic modes. The unwanted high-order characteristic modes can be effectively suppressed with the use of the interaction. When only the fundamental mode is effectively excited, the metasurface antenna shows high-gain performance. A high-gain metasurface antenna operating at 5.8 GHz is designed, fabricated, and measured. The antenna with dimensions of 1.5
$\lambda _{0}\times 0.83\lambda _{0}\times 0.11\lambda _{0}$
(
$\lambda _0$
is the vacuum wavelength at 5.8 GHz) has a bandwidth of 4.6% with
$|S_{11}|< $
$-$
10 dB. The realized peak boresight gain of 11.5 dBi within the passband and the half-power beamwidth of 28
$^{\circ }$
–37
$^{\circ }$
in the E-plane are obtained.