Research And Design Of Circular Polarization Antenna

In recent years,with the rapid development of wireless communication industry,the electromagnetic space environment has become complex,and the reliability and stability of radio communication system have faced more and more serious challenges and tests.Compared to linear polarized antennas,circular polarized antennas are more adaptable to the complex electromagnetic environment and can effectively improve the reliability of antenna system.Nowadays,circular polarization technology has been used in many communication fields,such as RFID,GNSS,Wireless for military,Radar and so on.In this paper,based on the application background of circularly polarized antenna,the research status of circularly polarized antenna in communication field is described,reveals the main technical means to realize circular polarization.Based on this,three circularly polarized antennas with excellent performance are designed.Based on the simulation design of circularly polarized antenna,a circularly polarized slot antenna,a dual band circularly polarized monopole antenna and a circularly polarized reconfigurable microstrip trapezoidal monopole antenna are designed.The main work of this paper are listed as follows:1.A circularly polarized slot antenna.The antenna consists of a square radiator loaded with two L-shaped slots and an I-shaped slot and two short-ended routes.It is fed by a patch on the other side of the dielectric substrate.A 1/4 wavelength impedance converter is loaded between the feeder and the feeding patch.In the left-hand circular polarization mode,the operating bandwidth is 1.18-1.37 GHz,and the circular polarization bandwidth is about13.0%.2.A dual band circularly polarized monopole antenna with wide axial ratio bandwidth.The antenna consists of a rectangular radiation unit with a microstrip feeder and its L-shaped branches,an isosceles right triangle-shaped ground,and a dielectric substrate.This antenna has two working bands.In the low frequency band,the operating bandwidth is 1.05-1.75 GHz,and the circular polarization bandwidth is about 50.0%,which can be used by GNSS(GNSS).In the high-frequency band,the operating bandwidth is 2.27-3.28 GHz,and the circular polarization bandwidth is about 36.4% for wireless local area network(WLAN).3.A circular polarization reconfigurable microstrip trapezoidal monopole antenna with wide axis ratio bandwidth.The antenna consists of two trapezoidal zigzag monopole,a switchable feed network and a right-angle isosceles triangle ground.The antenna is circular polarization reconfigurable.When it works in right-hand circular polarization mode,theoperating band is 1.17-1.74 GHz,and the circular polarization bandwidth is 39.2%.Whereas in the left-hand circular polarization mode,the operating bandwidth is 1.18-1.74 GHz,and the circular polarization bandwidth is about 38.4%.The antenna covers the working band of the GNSS.Simulations and parameter optimizations of the three above antennas have been conducted in this paper.The simulation and measurement results reveal that all the wide axial ratio band circular polarization techniques proposed in this paper have theoretical basis and practical value.