An Endfire Beam-Switchable Antenna Array Used in Vehicular Environment

An endfire beam-switchable antenna array, which is designed for vehicular mobile application regulated by the IEEE 802.11p standard, is proposed in this letter. The antenna is a linear array with four L-shaped elements separated by a quarter of a wavelength. The horizontal beams of L-elements point to four different directions, and this reduces the antenna height, decreases the mutual coupling between elements, and also eliminates the blind zone in the broadside direction. The antenna array has two isolated ports. By switching between two ports, the endfire radiation pattern can be switched toward opposite directions. A prototype antenna is built to verify the concept. The gain of the prototype is better than 6 dBi, and the impedance matching is better than -14 dB in the working band (5.8505.925 GHz).