Research And Design Of Polarized Reconfigurable Antenna In Multiband

With the continuous development of space technology,the space of the satellite communication front-end is becoming more and more limited.Therefore,the miniaturization and common-aperture multiplexing of antennas and radio frequency modules have become an important direction for technological development in this field.This paper is oriented to the application requirements of multi-frequency space communication and navigation system,explores a new method of integrated design of circularly polarized reconfigurable filter antenna,and completes the prototype design of reconfigurable filter antenna on this basis to verify the feasibility of the technical solution.In the traditional array antenna design,the filter network and polarization control are often two independent functional units.This paper combines the two parts into one.In the process of phase control,the filter characteristics of the coupled resonator are used to realize the phase and filter;combined with the switch circuit to switch the working frequency of the antenna to realize the tunable working frequency;on this basis,the basic principle of the circularly polarized antenna array is further used to finally complete the circularly polarized array antenna with reconfigurable frequency and polarization the design of.The specific content of this article is as follows:(1)The array element design of the circularly polarized antenna is carried out,and the circularly polarized patch antenna unit is designed and simulated based on two methods of single feed and double feed.In this paper,a single-feed method is used to design an X-band right-handed circularly polarized antenna with a vertical coupling circuit topology.The antenna patch is fed two ways through the slot resonator coupling network,and a positive structure is constructed in the two-way feed.Cross the phase difference to produce circular polarization,while achieving the effect of reducing the size;in the double-feed method,patch antenna units working in the L,S,and X bands are designed separately,using the different phases between the two feed points.The difference realizes the circular polarization of different rotation directions,and determines the best plan for reconfiguration of the antenna.(2)Aiming at frequency reconfigurable and polarization reconfigurable based on the doublefed method,a feed control circuit with both polarization control and filtering functions is designed.In the case of inputting the same signal,the circuit can be controlled The output phase difference of the two signals is switched between +90� and-90� to realize the left-hand and right-hand adjustment of the antenna polarization.Designed and simulated the 3dB bridge of each band,and added it to the feed network to achieve orthogonal excitation phase;designed and simulated the halfwavelength coupled resonant ring of multiple bands,based on its filtering performance and phase characteristics,combined polarization control,The two devices in the band are cascaded and assembled into a feed control circuit;using electromagnetic field simulation tools,the antenna unit and feed circuit in different states are integrated,debugged,and simulated and optimized,and the phase required by the reconfigurable antenna are realized.Amplitude parameter adjustment;completed the physical preparation and test of the antenna sample,and combined with the switch circuit to realize the adjustment of the circular polarization state.The test results show that the designed antenna can realize the two polarization control functions of left and right rotation,and has good standing wave,axial ratio and radiation characteristics.(3)The array antenna is designed and simulated based on the single-chip structure.The array size is 4�4,with a total of 16 array elements.The simulation results show that the designed array antenna can be reconfigurable in the three frequency bands of L,S and X.A typical antenna array working in the L-band has an impedance bandwidth of 15.2%(1.47GHz-1.72GHz)in both states,and the axial ratio bandwidth in the left-hand circular polarization state is 220MHz(1.44GHz-1.66GHz),The axial ratio bandwidth of the right-handed circular polarization state is 190MHz(1.47GHz-1.66GHz),the antenna gain in the maximum radiation direction is 20 dBic,the sidelobe level is 6.7dBic,and the maximum suppression of the cross-polarization level is up to-37 dBic,the front-to-back ratio on the XOZ plane is 41 dB,and the front-to-back ratio on the YOZ plane is 35 dB.