A Miniaturized Gain-Enhanced Antipodal Vivaldi Antenna and Its Array for 5G Communication Applications

In this paper, a miniaturized gain-enhanced antipodal Vivaldi antenna (AVA) with gradual corrugated edges (GCEs) and triangular metal directors (MDs) is investigated. Its operating frequency band is extended and the gain is improved at lower frequencies due to the use of GCEs. In addition, the E-plane beam tilt has been removed and the improvements on side-lobe level are achieved. By applying triangular MDs on the two surfaces of the radiation aperture of the AVA, its gain at higher frequencies is improved. Therefore, the gain variation tends to be flat within the whole operating band. Furthermore, a compact 1×8 E-plane AVA array with a small size of 54.4 × 28.2 × 0.508 mm3 is also designed, fabricated, and measured. A measured gain is 12.3-12.9 dB in the operating frequency band of 24.75-27.5 GHz, which covers the candidate band for the fifth generation (5G) communication. Good directivity, symmetrical radiation patterns, and compact structure make the proposed AVA array suitable for integration in devices for 5G communication applications.