Wideband Antenna in Cavity Based on Metasurfaces

A compact wideband printed antenna embedded in a half-wavelength cavity is introduced here. It consists of a strip-based metasurface printed in the cavity aperture. The principle of operation and key parameters are discussed. The numerical results are validated successfully around 2.3 GHz, and fractional -10-dB bandwidths reaching 31.8% and 34% are measured for cavity antenna prototypes without or with a surrounding ground plane, respectively. The corresponding measured radiation efficiencies and gain values at 2.3 GHz reach 92% and 87%, and 5.9 and 4.7 dBi, respectively.