Circular Polarized Leaky-Wave Antenna Research Based On ISGW Technology

With the rapid growth of the population and the increasing demand for information transmission of people,the antenna as an important part of the communication system is also developing towards the direction of multi-function,high efficiency and simplification.The advantages of the circularly polarized antenna against multipath interference and polarization misalignment make the circularly polarized antenna more widely used.The high gain and frequency scanning characteristics of leaky wave antennas make leaky wave antennas popular in radar,autonomous driving and other fields.Integrated-substance gap waveguides(ISGW)have less energy loss and no mode conversion problems compared to gap waveguides(GW)and substrate integrated waveguides(SIW),and the self-encapsulation feature has great potential in practical applications.Based on the basic theory of circularly polarized antenna and leaky wave antenna,this paper designs a circularly polarized leaky wave antenna on the basis of ISGW.The antenna has many advantages such as good performance,simple structure,easy manufacture,low cost,and wide application.The simulation results and some test results are given in this paper.The main work of this paper may summarize as follows:1.A L-shaped slot CP antenna based on ISGW is proposed.The surface current distribution of the antenna is studied by HFSS,and improvements made based on the characteristics of the surface current to obtain better impedance matching and axial ratio performance.2.On the basis of L-shaped slot antenna,a U-shaped slot CP antenna is proposed.By studying the electric field distribution of the slot,the shape of the slot got further improved,so that the U-shaped slot CP antenna has the advantages of wider axial ratio band width,better directivity and so on.Two kinds of circularly polarized antennas were compared,parameter analysis and results are given.3.Two kinds of circularly polarized leaky wave antenna arrays based on ISGW are proposed.Firstly,a 1×8U shaped slot array is simulated.Based on this,a 1×12U shaped slot array antenna is proposed after adjust the period and the number of elements.Eventually,it has better impedance matching and greatly reduces the open stop band(OSB)effect.Beam scanning across 0°,higher gain(about 17.5d B),wider axial ratio bandwidth(about 5 GHz)and wider scanning angle(about 40°)are achieved.The simulation performance of the two kinds of antennas is compared,and the 1×12U shaped slot array antenna is fabricated and tested.