Bidirectional multiple polarization antenna system

In this paper a new structure has been proposed to fit six antennas into a compact package. The six antennas can be divided into two sets. Each set of three antennas provide hemisphere coverage with three orthogonal polarizations. By using a back-to-back arrangement, the antenna can cover the whole sphere. A prototype of such bidirectional system has been manufactured for experimental measurement. The results show that the bandwidth of the antenna is 70 MHz (2.39 - 2.46 GHz) with return loss lower than -10 dB. Measured isolations between each two ports are better than -22 dB in the WLAN band (2.4 GHz - 2.484 GHz).