Gain-phase error calibration method of the uniform circular array based on orbital angular momentum

A calibration method based on orbital angular momentum (OAM) is proposed for gain-phase errors in uniform circular array (UCA). The idea of the method is to construct an objective function containing the gain-phase errors of the UCA based on the spectral peak search function of the multiple signal classification (MUSIC) algorithm, and take the UCA gain-phase errors as parameters to be optimized by the IWO-PSO (invasive weed optimization and particle swarm optimization) algorithm. The estimated values of the amplitude-phase errors are used to compensate for the array manifold, and the angular information of the unknown targets are obtained by the spectral peak search of the modified MUSIC algorithm. The method is of great significance for OAM radar systems in practical engineering applications.