The Channel Calibration Based On Antenna Array

High-frequency Ground Wave Radar(HFGWR)has advantage in monitoring marine environment in all-weather condition by horizontal polarized magnetic wave.In the application of HFGWR,the multiple classification(MUSIC)algorithm is used to estimate the signal direction of arrival(DOA).Ideally,the DOA estimation based on MUSIC algorithm has good performance.But in a practical application,the performance of MUSIC algorithm is weaken by the amplitude-phase error of receiving channels.Therefore,it is necessary to analyze the characteristic of amplitude-phase error,and study method to calibrate the receiving channels.This thesis analyzes and optimize the receiving channels errors of HFGWR.The channels errors were classified and the calibration method of amplitude-phase error were studied by antenna's architecture.The thesis is divided into the following parts:Part ?,MUSIC algorithm introduction and channel error analysis.Mathematic model of array antenna is founded to introduce the theory of MUSIC algorithm.Then the characteristic of amplitude-phase error is analyzed in theory.Finally,the impact of amplitude-phase error on MUSIC algorithm is studied by computer simulation.Part ?,Amplitude-phase calibration for array HFGWR.The main subject of this part is amplitude-phase calibration method for array antenna.Firstly,combined with the statistical characteristic of range Doppler spectrum,a screening method of single DOA spectrum point is introduced for the preparation of measured data calibration.Then,present two amplitude-phase error calibration methods for array antenna.1.Amplitude-phase calibration method for array antenna based on sea echo.Measured data are applied to validate the effectiveness of the method.2.Array amplitude-phase calibration on improved adaptive genetic algorithm(AGA)is proposed.The measurement result shows the availability of this method.Part ?,Amplitude-phase calibration for portable HFGWR.Portable HFGWR employ monopole/crossed-loop antenna as receiving device,which receiving channels have the same phase center.This part includes two amplitude-phase calibration methods:1.A monopole/crossed-loop antenna calibration method based on genetic simulated annealing algorithm is proposed.The feasibility of this method is verified by computer simulation.2.A phase calibration method for monopole/crossed-loop antenna based on sea echo is proposed.Compared with the cross-covariance estimation method,the measurement result shows the availability of the method.