Research And Software Implementation Of The Truncation Error Correction Method For Planar Near-field Measurement

Antenna measurement is an important method for theoretical research and production manufacturing of antennas,it also needs to improve measurement accuracy and system performance.The error analysis and correction method of the antenna measurement system is one of the research focuses in the field of antenna measurement at present.In this paper,the theory of near-far field transformation and the theory of finite scanning truncation errors correction are studied.The multi-band standard gain horn antennas and waveguide slot antenna are simulated and used to verify the above theories.The main works of this paper are as follows:The theory of plane wave spectrum is expounded and the relation between the far field pattern and the plane wave spectrum function is given.Based on the above theory,the near and far field transformation algorithm is given.Two methods for obtaining the gain of the antenna,absolute method and relative method are given.Several standard gain horn antennas were simulated using HFSS simulation software.The antenna patterns obtained by the near-far field transformation algorithm are compared with the theoretical patterns that confirms the effectiveness of the algorithm.The theoretical upper limit of the truncation error is derived based on the near-far field transformation theory.Aiming at the application limitations of the classical error correction method data continuation method,band-limited extrapolation theory is applied to truncation error correction,a new convergence criterion is defined and new window function is introduced.Based on the Gerchebrg-Papouis algorithm,a new method called the G-P correction algorithm for correcting truncation errors is proposed.A standard gain horn antenna with band of L and a longitudinal slot slotted waveguide antenna with band of Ku are simulated using HFSS and MATLAB simulation software,the theoretical results,truncation results and correction results of the antenna pattern are compared,the comparison results demonstrate the effectiveness of the G-P correction algorithm.Compared with the data extension method,the G-P correction algorithm has better correction effect and wider application range.An interface software for data processing and truncation error correction is compiled based on C# programming language and MATLAB.Aiming at the requirements of 3D antenna pattern display and data visualization interaction,a software implementation method based on Windows API for displaying pattern is proposed.Compared with the conventional method,it has better rendering effect and stronger extension function.The software uses the.Net Framework 4.7.2 framework.The development platform is the Visual Studio 2019 integrated development environment.The main interface of the Windows client software is built by the Winform suite.The software satisfies the basic data processing requirements,supports various forms of pattern,truncation error correction and multi-frequency processing and other special functions.