Design And Research Of Conformal Adaptive Array Mutual Coupling Calibration System

Under the background of the increasing demand for the miniaturization of antennas in modern communication equipments,the spacing between antenna elements in array antenna is further reduced.When the spacing is less than half a wavelength,the mutual coupling between the elements becomes more obvious,which will lead to distortion of radiation pattern and the increase of multipath components and other problems,which will seriously affect the working performance of the array antenna.In order to reduce or eliminate the mutual coupling effect,so that the array antenna can work normally,it is of great engineering application value to study suitable and effective mutual coupling calibration methods.Aiming at the mutual coupling effect in the application of conformal adaptive arrays,this paper will investigate and design the mutual coupling calibration method.Starting from the mechanism of mutual coupling effect,the calibration principles of various existing solutions are analyzed,and their advantages and disadvantages are compared and summarized.In this paper,a new signal calibration algorithm is proposed,and a conformal adaptive array mutual coupling calibration system is designed to verify the calibration effect of the algorithm.The main work of the dissertation includes the following aspects:Firstly,the current research status of the existing mutual coupling calibration methods is investigated,the calibration mechanism of each method is studied and analyzed,and the development and research status of conformal array antennas and RF receivers are studied,which will be used for the following research work.Then study the theoretical basis of the array antenna,and introduce the performance indicators of many typical arrays.The mechanism of mutual coupling effect is theoretically studied,and different mutual coupling analysis methods are analyzed and compared from the perspective of electromagnetic analysis.A new signal calibration method is proposed,and its theoretical principle is expounded.Then introduces the theoretical background of the related hardware system in this paper,introduces multiple performance indicators and their corresponding parameter indicators of the RF receiver in detail,and analyzes the structure and advantages and disadvantages of many mainstream receivers on the framework of the RF receiver.The design of the hardware environment is based on the theoretical foundation.Then carried out the design and test of the calibration system hardware.The antenna part uses a microstrip antenna as the basic unit,and linear polarized and circularly polarized eight-element conformal linear arrays are simulated.The maximum gain of the unit greater than 5d Bi.The reflection coefficient of the port at the center frequency is less than-12 d B.The RF receiver part uses a super-heterodyne structure.The performance indicators of the receiver are formulated,and the structure of each module is refined to determine the selection of each device.The digital signal processing part uses an 8-channel high-speed digital signal processing platform.Then carry out the test and debugging of the hardware system,test the VSWR and radiation pattern of the antenna.In the RF receiver part firstly completes the simulation of the link,and then uses the PCB software to perform the hardware implementation of the receiver,then tests and debugs the physical performance.Finally,an overall signal calibration test system is built,and experiments are performed to verify the proposed element pattern reconstruction method.The experimental data is compared to analyze the calibration effect of two different antenna arrays to verify the feasibility and effectiveness of the algorithm.