Polarization diversity unidirectional antenna for IEEE 802.11a applications

The polarization diversity unidirectional antenna is proposed for IEEE 802.11a applications by using two-probe excited circular ring antenna above square reflector. The purpose of this investigation is to design a polarization diversity unidirectional antenna to resonate at the center frequency of 5.5 GHz to cover the frequency range from 5.2 to 5.8 GHz for wireless LAN system following IEEE 802.11a standard. The performances of the antenna such as the return loss, the isolation between two-probes, the radiation pattern and the gain, are analyzed by using Computer Simulation Technology (CST) Microwave Studio. The proposed antenna has a polarization diversity unidirectional pattern with maximum gain of 8.34 dBi. Moreover, the proposed antenna yields the front-to-back ratio better than 20 dB and the isolation between the two-probes better than 20 dB as well. Besides, the proposed antenna is useful for wireless local area network (WLAN) communication systems.