An omnidirectional printed dipole array antenna with shaped radiation pattern in the elevation plane

An onmidirectional printed dipole array antenna (OPDAA) suitable for the vehicle loaded mobile communication in the UHF is presented in this paper. This OPDAA consists of 1x4 printed dipoles of identical dimensions, which are arranged symmetrically with respect to the central feed twin-lines. The parameter design, feeding method and optimization process of the proposed OPDAA are presented. Effects of the spacing among the four double-sided dipoles on the performance of the antenna are also studied in detail. The experimental results show that good onmidirectional radiation with gain variations less than 0.7 dBi in the azimuth plane and the shaped radiation pattern in the elevation plane fit for the practical application of communication have been obtained. The impedance bandwidth of VSWR<1.5 reaches 3.5% and the measured maximum antenna gain across the operating frequency band is about 6.4-6.9 dBi. Hence the OPDAA is very suitable for the vehicle loaded mobile communication particularly communicating with the aerial objects.