Voltage Programming Pixel Circuit Design For Compensation Threshold Voltage And Mobility

Circularly polarized antenna can receive incoming waves from any line polarization,and can also improve the Faraday rotation effect of signal transmission in the ionosphere,so it is widely used in satellite communication,navigation and positioning systems.Considering the strong anti-jamming ability of circularly polarized antenna,it can be used in civil microwave inductor.Therefore,this paper studied and researched circularly polarized antenna deeply and designed two kinds of circularly polarized antennas which are applied to civil microwave inductor.The main research contents are as follows:The research status and progress of circularly polarized antennas are reviewed,and the radiation mechanism of circularly polarized antennas is introduced.In order to improve the stability and reliability of the microwave inductor,they are applied to the microwave inductor through the process of design,simulation and physical test.Firstly,a double-fed circularly polarized antenna is proposed and designed.Based on the microstrip patch antenna,the overall structure of the antenna is mainly divided into three layers: the first layer is the ground,the second layer is the substrate,and the Rogers RO4003(TM)material is selected,and the third layer is the radiation source.Through the power splitter,the two feed points are allocated equal power and the required phase difference to achieve circular polarization radiation.In the high-frequency electromagnetic simulation software,the parameters of the antenna,such as gain(7d B),return loss(-18),impedance matching,axial ratio width and other parameters,all reach a good effect.Through the test of the real object,it is finally applied to the microwave sensor,and has also achieved a good effect.Second,a kind of quad-feed patch circularly polarized antenna is proposed,which is based on the doubly fed circularly polarized antenna,and has been expanded to some extent.Compared with dual-feed,it has some significant advantages: wider impedance matching bandwidth,better axial to axial ratio,wider 3d B axial ratio beam width,and good symmetrical gain and axial ratio pattern.In this paper,the circularly polarized wave radiation is realized by feeding network method.A copper column is added to the outermost layer of the antenna,and a copper cone is added to the top and bottom of the radiation source respectively.These metal objects can improve the directional radiation of the antenna by changing the radiation.Antenna design in this paper is done on the basis of the microstrip patch antenna,with the unique advantage of circular polarization antenna in radiation,by a new design of overall structure,optimization and so on to make it more suitable for circular polarization antenna,not only give full play to the advantages of circular polarization antenna,also can guarantee the microwave sensors on various aspects of performance.It has good engineering practical value.