Miniaturization And Wideband Design For 5G Dual-Polarized Base Station Antenna

In recent years,with the increasing need of high rate and low latency technology in mobile communication,the fifth generation(5G)mobile communication has received more and more attention.As an important part of 5G mobile communication system,the design of 5G dualpolarized base station antenna has become one of the research hotspots.Due to the shortage of base station site resources,the miniaturization and broadband of base station antenna and the research of multi-band shaped-aperture of base station antenna have become the development trend of base station antenna.In this thesis,the base station antenna miniaturization,broadband and multi-band shaped-aperture of base station antenna are studied.The research content is mainly divided into the following three parts:1.Research and design a 5G compacted base station antenna with optimizing the shape of the slot on the radiator.The antenna is composed of three parts: radiator,feeding baluns and metal reflector.The current path can be extended by optimizing the shape of the slot on the radiator,and adding extra arms can also extend current patch.Finally,antenna miniaturization is realized by the combined action of the two methods.Simulated and measured results show that return loss of the proposed antenna is more than 14.5 d B and isolation of two ports is better than 30 d B in the band of 3.4-3.6 GHz.Antenna size is only 0.21?(? is the wavelength corresponding to the central band of 3.5 GHz).Based on the antenna element,a five-element antenna array is designed in this thesis.2.Research and design a 5G broadband base station antenna with shape optimization of radiator.The proposed antenna is composed of two crossed butterfly radiator,half of the arm in the same polarization direction is located on the FR4 dielectric substrate,another half of arm lies below the FR4 dielectric substrate,and fed directly through the coaxial line.By optimizing the shape of the radiator,the coupling between the arms is changed to expand the antenna bandwidth.Simulated and measured results show that return loss of the proposed broadband base station antenna is bigger than 15 d B and isolation of two ports is better than 25 d B in the band of 3.3-5GHz.The antenna size is 0.38?(? is the wavelength corresponding to the 4.15 GHz central frequency band).Compared with other wideband antennas,the proposed broadband base station antenna has a steady radiation characteristic.In this thesis,a seven-element antenna array is designed based on the proposed antenna element.3.Research and design a 2G/3G/4G/5G multi-band shaped-aperture base station antenna with loading ADS(Array-Antenna Decoupling Surface,ADS)structure.The shaped-aperture antenna consists of a low frequency antenna element which works at 1.7-2.7 GHz and four high frequency antenna elements which work at 3.3-5 GHz.The four high frequency elements are set around the low frequency element.Because the high frequency element is very close to the low frequency element,hence the coupling between the high and low frequency elements is very large.By loading ADS structure above the antenna,the coupling between the high and low frequency elements is inhibited,and the high and low frequency elements can maintain a stable pattern in their respective working frequency bands.Measured results show that both the low frequency element and high frequency element have good impedance matching in the operating band of 1.7-2.7 GHz and 3.3-5 GHz,and the isolation of high and low frequency in their working frequency band is greater than18 d B.