Compact Tilted Beam Steering Patch Antenna for Vehicular Applications

Abstract

A compact low profile beam steering antenna is presented for vehicular applications. The proposed antenna structure is a square patch antenna, which contains a row of shorting vias in both horizontal and vertical directions, underneath the patch. The square patch is fed using co-axial probe in four quadrants. By switching over the different sets of feeding ports in four quadrants, four tilted beams, which can scan the entire azimuth plane, are obtained. Besides the azimuth scanning, the tilted beam can also scans broadside from 2° to 45° as a function of frequency within 3-dB gain band by using coupled mode concept. The simulated antenna realizes bandwidth of 40 MHz with center frequency of 2.4 GHz and a gain of 6.7 dBi. The front to back ratio is -13dB, and the beam width in the elevation (Azimuth) plane is switchable from 75° (56°) to 86° (90°). The proposed antenna has a thickness of 3.2 mm and it is compact, easy to fabricate, and therefore it can be easily hidden on the roof of vehicles to transform internet access from base station and satellite.