Analysis and Design of Sub-6 Beam Steerable Antenna Array Using Meta-material Loaded Vivaldi Elements.

in this paper, a sub-6 beam-steerable antenna array system is introduced. The main radiating element in the proposed array is a gain-enhanced Vivaldi antenna, whose overall realized gain is improved by introducing near-zero-index metamaterial [NZIM] with broadband characteristics at 3.6 GHz. The proposed system is intended to be integrated with fifth-generation (5G) automotive applications. The 4x4 butler matrix is resonating at 3.6 GHz to feed the designed antenna array elements and steer the radiating beam, which is suitable for automotive applications. All the system components, including antenna elements and the [4x4] butler matrix, are designed, simulated, and optimized by using CSTMWS 2020 and HFSS. In order to verify the proposed design, the system is fabricated using the photolithographic technique. The experimental results show very good agreement with the simulated ones. The NZIM-loaded antenna element achieves a -10 dB bandwidth of 2.9 GHz, while the overall array system achieves a 600 MHz bandwidth. The steered beam of the proposed system has an overall realized gain of 11.2 dB and covers an angle from 45 o to 135 o .