A New Method for Achieving Miniaturization and Gain Enhancement of Vivaldi Antenna Array Based on Anisotropic Metasurface

A low-profile printed planar antipodal Vivaldi antenna (AVA) array with good performance for future fifth-generation (5G) millimeter-wave (mmWave) communication applications is presented. The proposed structure is an 8 × 1 array with eight elements in E-plane, which is fed by a 1-to-8 power divider network. A novel feature called anisotropic metasurface (MS) is located at the aperture, resulting in low cutoff frequency reduced from 24.55 to 24.1 GHz for miniaturization. In addition, the phase distribution located at the aperture of AVA array can be corrected by adding MS. Thus, the gain of AVA array can be improved from 8.5-11.2 to 9.35-12 dB in the frequency band of 5G mmWave communication. Finally, to verify the designed methods, the proposed AVA with MS (AVA-MS) array was successfully fabricated and measured, which occupies an area of 6.11λg × 2.93λg × 0.08λg. The numerical and experimental results coincide well with each other, which certify the new method for achieving miniaturization and gain enhancement of our proposed AVA-MS array.