Vehicular spoiler antenna for high data rate WLAN

For high speed digital data connection such as WiMAX or WLAN, a good signal to noise ratio (S/N) is required. One way to keep up a good S/N-value while moving is the use of high gain antennas with a directive antenna beam. However, often there is insufficient room to place high gain antennas in a vehicle. On top if this, it is becoming increasingly difficult and more packed in the car, so that progressive antenna approaches are enforced. As a vehicle can move towards and away from the transmitter site in any azimuth angle, the antenna shall offer some omni-directionality. In this paper, an antenna for 2.45 GHz WLAN is described. It is very thin of 4 mm, and it offers 12 dBi antenna gain with almost omni-directional but very beneficial radiation characteristics with "rabbit-ear" shaped double-lobes. Moreover it can be easily implemented into the plastic spoiler on a hatchback vehicle. Experiments proof that this flat WLAN antenna structure in a spoiler outperforms monopoles and patch antennas on rooftop in any respect. When tuning to the right frequency, this antenna is ideally suited for Car2X-applications and Wireless Internet utilization such as WiMAX and WLAN.