The Research Of Dual-Polarized Microstrip Antenna Array And It's Application In TD-SCDMA Smart Antenna

To solution the exposted problem in the test of TD-SCDMA mobile system, a new dual-polarized microstrip patch and antenna array is proposed,based on the analysis of the finite-difference time-domain (FDTD)method.And a smart antenna on-line calibration network is designed.The design an array is presented and investigated,fit for TD-SCDMA system.First,the effects of dual-polarized square patch antenna physical parameters are analyzed by the FDTD method.Then the base microstip antenna square patch is designed.The element is the dual-polarized corner-fed, while the vertical polarization port of the array is fed with a coplanar feed,and its horizontal polarization port is fed with the aperture-coupled feed.To improve the performance of bandwidth of microstrip square patch, air gaps are imported.Based on the microstrip square patch, the design of a novel 1X16 dual-polarized linear microstrip antenna array is introduced.The antenna array fit to construct the smart antenna of wave-shaped.In addition, the pair-wise anti-phase feeding technique is used in both feed networks.The sidelobe and the backlobe of the antenna array is lower than-20dB on E and H plane.By comparing the amplitudes and the phases extracts from each antenna element port,the offset values were obtained.The designed calibration network is simulated and built by using Ansoft HFSS,and fit for the specially of the dual-polarized linear microstrip antenna array.The paper also analyzed the eigenvalue distribution in environment with different angle spread and DOA.then,the performance of different beamforming algorithma are investigated first in diverse environment.The beamforming scheme based on the eigenvalue distribution is proposed,which can adaptively utilized different beamforming algotithm according to the eigenvalue distribution.The experimental results show that the bandwidth is extended to 23—25%,VSWR<1.5,the isolation between the dual polarization ports is better than 33dB.The cross-polarization level are fit for TD-SCDMA.The antenna linear array is fit for the element of smart antenna of 3G/4G mobile communication system.