Antennas Research And Design For5GHz WLAN System Application

With the rapid development of modern communication systems, the role of the antenna in a wireless communication systems draws more and more attention. Based on a common wireless communication system, WLAN (Wireless Local Area System), the thesis introduces a dual-polarized, high gain antenna array for5GHz WLAN application. The thesis also introduces a wide band FSS (Frequency Selective Surface) to raise the antenna element’s gain.WLAN technology is the LAN transmitted based on radio wave to achieve data transmission. As its advantages like flexibility and mobility, WLAN has developed rapid and now widely used in network coverage for public areas. In this thesis, a dual-polarized high gain antenna array will be designed for5GHz WLAN system. The total bandwidth of the proposed antenna array is1.15GHz (5.05-6.2GHz, S11<-10dB, S22<-10dB) with port isolation less than-15dB. The antenna array also achieved high gain, with maximum gain reached15.3dBi. The proposed antenna array can simultaneously achieve dual-polarized and high gain characteristics, with compact structure and small size. Thus the research work of the array has practical application significance.Frequency selective surface is basically composed of identical path or aperture elements periodically arranged in2D infinite array. The unique spatial filtering characteristic of FSS to incident electromagnetic waves with different polarizations and angles of incidence activates its extensive use in electromagnetic domain. In this thesis, a wide band FSS will be designed to work with the WLAN antenna element to raise the total gain. The bandwidth of the FSS is1GHz(5-6GHz, S11<-10dB), the F-P system’ s gain reached10.3dBi, the gain of element is only7dBi.In this thesis, the proposed antenna array is also fabricated and measured after these antennas meet the communication requirements of WLAN systems. The measurement results show that the proposed WLAN dual-polarized antenna array achieves good performance, and can be utilized in practical WLAN network coverage applications.