Study And Design Of The Planar Transmitarray Antenna

As the transmitting and receiving device of wireless communication system,the antenna directly affects the performance of the communication system.Compared with the parabolic antenna,the plane array antenna is feed by horn antenna,which avoids the complex feeding network.As a kind of array antenna,planar transmitarray antenna has the advantages of high aperture efficiency and low sidelobe,so it has been widely concerned by domestic and foreign scholar.In this dissertation,the planar transmitarray antenna is taken as the research object,and the research status of the transmitarray antenna by domestic and foreign scholar in recent years is introduced.Starting from the basic principle of the array antenna,the performance indexes such as aperture efficiency,bandwidth,gain and so on are emphatically studied.The main work of this dissertation is as follows:Firstly,the study of broadband transmitarray antenna.A novel three-layer transmitarray element is proposed.By introducing different intermediate layers,the resonance points of the element are increased to improve the bandwidth.In order to verify the effectiveness of the transmitarray element,a transmitarray antenna consists of 15×15 elements was designed and fabricated.The experimental results show that the designed transmitarray antenna has 14.8% 1-d B bandwidth.Secondly,the study of broadband efficient transmitarray antenna.A transmitarray element with metal vias is proposed.The transmission phase of the element can reach360° with only two layers of metal patch and one layer of medium substrate,which can save the production cost very well.In order to verify its high bandwidth performance,a transmitarray antenna containing 225 elements was fabricated and fabricated.The measurement results show that the 1-d B bandwidth of the antenna is14.9%,the aperture efficiency is 46.6%.The measurement results show that the designed transmitarray antenna has high bandwidth and high efficiency.Finally,the study of dual-frequency transmitarray antenna.A transmitarray element which can work in both X and Ku band is proposed.The transmitarray element consists of four layers of metal patches,each layer of which is composed of square ring and cross ring structure.By optimizing the parameters,the transmitarray element can achieve a transmission phase greater than 360° and can operate independently in both frequency bands.In order to verify the dual-frequency characteristics of the element,a dual-band transmitarray antenna with 201 elements was fabricated and fabricated.The measurement results show that the gain of the dual-band transmitarray antenna at 11.5GHz is 22.4d B,and the corresponding aperture efficiency is 52.7%.The gain at 13 GHz is 24.2d B and the corresponding aperture efficiency is 62.4%.The antenna has a 1-d B bandwidth of 9.7%(10.8-11.9GHz)in the X band and 9%(12.6-13.8GHz)in the Ku band.