Abstract:Compared to traditional terahertz holographic imaging algorithm for short-distance targets based on spherical wave decomposition, the same imaging compensation formula is obtained based on the theory of stationary phase method. By analyzing the effect of array elements error on imaging results using the criterion of image entropy, it provides the theory basis to the design of the array elements position precision of imaging system. Aiming at the defocusing and fuzzy in 3-D targets imaging results at non-compensation distance which is too close, the defects of traditional imaging algorithm are analyzed, and terahertz 3-D holographic imaging method is proposed for short-distance target based on the combination of loop compensation and projection synthesis. The Matlab simulation results at 220 GHz show the effectiveness of the proposed method, which realizes the focused imaging of three-dimensional targets.