A Broadband Low-Profile Dual-Linearly Polarized Dipole-Driven Metasurface Antenna

A low-profile broadband metasurface antenna (MSA) with dual-linear polarization is developed. The developed MSA mainly consists of a 4 x 4 grid-slotted patch array, two pairs of orthogonally printed feeding dipole strips, two vertically grounded and orthogonally placed microstrip Gamma-shaped feeding structures, and an intact ground plane. It is demonstrated that the strip-excited MSA excites a leaky wave mode, a surface wave mode, and a dipole mode to provide a wide operational bandwidth. The prototype, with an overall size of 0.65 lambda(0) x 0.65 lambda(0) x 0.07 lambda(0) (lambda(0) is the wavelength in free space at the center operating frequency) was fabricated and measured. Three modes with broadside radiation patterns for each port are simultaneously excited to create a wide impedance bandwidth 36% with the average gain value 9.3 dBi. Moreover, the port-to-port isolation and the cross-polarization discrimination (XPD) are, respectively, higher than 26 and 25 dB.