On The Dual-polarized And High-gain Yiga-Uda Antenna And Satellite Navigation Antenna For CNSS/GPS Systems

The research work is from the scientific projects.The main research work can be divided into three parts: Fabrications of dual-polarized and high-gain Yiga-Uda antenna applied in the Pico satellite earth station received system and circular polarized feed-network are proposed in the first part;Then,Widebeam circularly polarized antennas applied in CNSS and GPS,respectively,are present in the second part;Finally,Dual-band stacked circularly polarized antenna implemented in CNSS are introduced in the third part.The main contexts of the thesis are as follows:The first part is fabrications of dual-polarized and high-gain Yiga-Uda antenna applied in the Pico satellite earth station received system and circularly polarized feed-network.Firstly,the application background of project's requirements and the design theory of traditional Yiga-Uda antenna are discussed.And then,according to technical demands,we analysis the technological difficult point,finally,we choose Yiga-Uda antenna as the design scheme of dual-polarized and high-gain antenna applied in Pico satellite earth station received system.In order to achieve the characteristic of dual polarization,we use two same Yiga-Uda antennas which are orthogonally fixed at the platform.The proposed antenna is simulated and optimized using the ANSYS High Frequency Structure Simulator(HFSS).The simulated results presents that the proposed antenna can satisfy the technical specification.On the basic of simulated results,we fabricate the prototype.The measured results show that gain at the center of operating band is 14.5dB,VSWR?2 and the proposed antenna has the characteristic of dual polarization.In order to achieve high-gain circular polarized radiation of the proposed antenna,the paper designs a compact circularly polarized feed-network.The simulated and measured results show that within the working band,VSWR?1.5 and within the allowed error of engineering,the measured results satisfies the requirements of amplitude and phase for circular polarization.The proposed antenna has successfully applied in the Pico satellite earth station received system.The second part is the design of widebeam circularly polarized antennas applied in CNSS and GPS system,respectively.For satisfying the requirements of widebeam antenna applied in satellite signal receiving system,the paper designs,respectively,QHA for GPS and low profile widebeam circularly polarized antenna for CNSS,using stepped-widths radiation arms.The simulated results show that at the working band,VSWR?2,both of the proposed antenna have 3dB AR beamwidths of more than 180°,covering the upper space.And the circularly polarized gain at low elevation angle is high.According to the simulated results,we fabricate and measure the prototype of low profile widebeam circularly polarized antenna.The measured results are in agreement with simulated results,which prove the effectiveness of the proposed antenna.The third part is the design of dual-band stacked circularly polarized antenna implemented in CNSS.Based on the research background of the engineering requirement of CNSS duplex communication and combining with circularly polarized theory of microstrip antenna and QHA,The paper designs and simulates a stacked circularly polarized microstrip antenna and a stacked QHA based on the short-ended QHA.The simulated results show that the characteristic of impedance and circularly polarized radiation can satisfy the requirements of duplex communication.And then we fabricate,adjust and measure the stacked circularly polarized microstrip antenna.The measured result shows that within receiving and emitting band,VSWR?2 and ARs at the center of receiving and emitting band are 2d B and 0.8dB,respectively.Circularly polarized gains are 6.8dBic and 7dBic,respectively.The measured results can satisfy the technical requirements.