| At the end of 2018,China announced the completion of the construction of Beidou III basic system and began to provide global services,which means that Beidou will have more abundant applications in future daily life,and the satellite navigation industry is expected to usher in a new wave of development boom.Antenna,as the key RF front-end device for receiving and transmitting satellite navigation signals,has important research significance and practical value.Because circularly polarized wave can reduce the influence of Faraday rotation and multipath effect on satellite communication,it is widely used in satellite navigation antenna.Multi-band antenna and wide-beam antenna can receive more navigation satellite signals,which is very helpful to improve navigation positioning accuracy and shorten acquisition time.Firstly,this paper introduces the research status of compact multi-frequency wide beamwidth navigation antennas,focuses on the method of generating circularly polarized waves,deeply studies the radiation mechanism of patch antennas,and then designs a low profile five-frequency circular polarization patch antenna for vehicle navigation.The antenna covers five frequency bands of Beidou and GPS by multi-layer stacking technology,and realizes dual polarization by using RF chip feeding.In addition,the application of the radial strip line technology makes the antenna easy to debug and helps to improve the low elevation gain.At the same time,the antenna meets the requirements of the established radio frequency specifications in multi-band,polarization gain,axis ratio,roundness and vibration resistance.The proposed antenna has compact structure,simple design and easy processing,which makes it more practical.In order to increase the beam width and the low elevation gain and shorten the time of acquiring satellites,a compact four-arm IFA antenna with wide beam is designed by sequential rotation feeding method based on the theory of wide beam antenna and the advantage of easy matching of IFA antenna structure.The antenna uses LDS technology to laser the shape of four IFA antennas on the PC/ABS material,and then feeds it with a four-phase coupler chip on the FR-4 high frequency board.This gives the antenna a very good axial-ratio characteristics.The 3dB beamwidth reaches 140 degrees.The application of bending line technology can reduce the size of antenna to 0.106??0.106??0.072?,without reducing the radiation performance.Through the joint simulation with the circuit simulation software AWR,the differences between the actual measurement and simulation are analyzed and adjusted,and the optimized structure is obtained.Aiming at the requirements of circular polarization,wide beam,multi-frequency and miniaturization of navigation antenna,a low profile multi-frequency circular polarization patch antenna and a compact wide beamwidth four-arm IFA antenna are simulated,designed and tested.The results of microwave anechoic chamber test and software simulation are basically consistent. |
PDF Full Text Request