Research On Beidou Multi-band And Broadband Circularly Polarization Microstrip Antenna

With the rapid development of human communication,satellite navigation system applications have been fully penetrated into all aspects of human life,such as position-ing,communication,military are inseparable from the navigation system.With the in-crease in application requirements,the requirements of satellite navigation antenna to miniaturization,multi-band,intelligent development now.It is in this context,for min-iaturization,multi-band compatibility and multi-system compatibility and other issues,this paper research on multi-band and broadband circular polarization antenna.The main work of this paper is as follows:1.Research on single-layer BeiDou dual-mode dual-band microstrip antenna.The proposed antenna operating frequency band designed for the BeiDou B2 and S band.With the use of T-shaped slot loading on antenna,the antenna operates in the TMio and TM30 mode at two frequencies,while the four L-shaped gap inside of the patch improve the return loss of the antenna,and cutting the angle on the diagonal of the internal patch improve the axial ratio at the high frequency.On the basis of the above antenna,four CSRR structures are added to the inner patch of the antenna,improving the stability of the phase center of the antenna,and the design of the high performance BeiDou dual frequency antenna is realized.2.Research on dual frequency stack and slot circular polarization antenna covering the BeiDou B1 and B2 frequency band.The first proposed antenna is the double-fre-quency circular polarization stack antenna,the step loading on the diagonal of lower patch forming a circular polarization characteristic.Four L-shaped gaps are used in the upper layer of the antenna to improve the return loss characteristics of the antenna at high frequency.The second antenna is a dual-gap nesting dual-frequency circular po-larization antenna,through the microstrip line feed and a rectangular patch coupling,making the antenna in the cross direction 90° phase difference,by adjusting the gap of ladder gap and microstrip line with the patch distance,to achieve better dual-frequency circular polarization characteristic.3.Research on broadband circular polarization crossed dipole antenna covering the BeiDou and GPS bands.The first antenna is a diamond-shaped cross-dipole antenna,through the fractal means to increase the equivalent length of the antenna,reduce the size of the antenna,while ensuring the antenna has a wide impedance bandwidth and circular polarization bandwidth.The antenna can partially cover the BeiDou and GPS band.The second antenna is a circular recursive cross-dipole antenna with CSRR loaded.The antenna uses a recursive increased circular patch as the arm of the dipole antenna,the CSRR structure is loaded inside the circular patch to increase the length of the antenna.The antenna achieves a wide range of impedance and covering the BeiDou and GPS bands,can simultaneously receive two positioning navigation system signal.