Research On Dual-band And Broadband Array Antennas For Wireless Communication Systems

With the rapid development of modern wireless communication technology,antenna which has the advantage of miniaturization, muti frequency and broadband isin great demand. Printed dipole antenna has the outstanding properties of small size,light weight, easily fabricated and integrated into other microwave circuits, besides, itis easy to implement muti band and broadband characteristics, so it has been widelyused in wireless communication systems.This paper is mainly on two aspects:Firstly, two dual band and omni directional printed dipole antennas for WLANterminal equipment are proposed. Employing the unique tapered structure, good wideimpedance matching can be achieved conveniently. We also implement miniaturizationand dual frequency properties through etching several slots on the arms of the dipoleantennas. For the first antenna, we etch two L slots on each arm, and for the secondantenna, we adopt etching several parallel slots to obtain more compact size comparedwith the first one.The proposed antennas are both capable of covering the twooperating bandwidths of WLAN. Besides, they have a nearly omni directionalradiation pattern in the H plane and ultra low cross polarization levels at the twoprincipal planes across the entire bandwidth. At last, the antennas are fabricated andmeasured, both the simulated and measured results are in good agreement.Secondly, in order to meet the requirements of the large capacity for wirelesscommunication systems, a broadband printed dipole array is presented. The entireprocess of designing is described in this paper, on the basis of the wideband unit andpower divider, we design a broadband printed dipole array. Finally, according to thesimulation results the antenna is fabricated and tested, the proposed array antenna has awide impedance bandwidth of43%at2.2GHz, and the experimental results fullyverify the concept.