Research On Technology Of Probe Correction In Antenna’s Planar Near-field Measurement

Antenna measurement technology is an important method for antenna designers to design and verify.With the rapid development of microwave communication,satellite navigation and radar technology,the requirements for antenna parameter accuracy are higher.For ultra-low-side-lobe antenna and high-frequency-horn antenna,the conventional far-field test method is no longer applicable.For the problem,we propose plane near-field measurement techniques.The technology uses a probe with known characteristics collect the electric field information on a certain plane and can attain the accurate far-field characteristics of the antenna through rigorous mathematical calculations with probe correction in the near-field area of the antenna.The planar near-field measurement and probe correction theories were deduced based on the plane wave expansion theory in the thesis and then the thesis introduces the principles of plane near-field scanning and scanning interval selection.Then the thesis takes the actual planar near-field test system as an example and the thesis describes the functions of the test chamber system,test structure and the antenna automatic test system.In this subject,the actual pyramidal horn antenna was tested.The subject takes a research to the direct method and comparative method of the antenna gain in planar near field test system and the subject studies the antenna gain extrapolation test method.To solve the non-replaceable feature of the acquisition probe,the thesis brings up the probe pattern acquisition methods based on the characteristics of the sampling probe,including the theoretical formula method,the extrapolation test method and the probe simulation method,and compares the three methods.Finally,according to the probe correction formula,using the existing probe pattern and strict near-far field transform formula,the thesis proposes the planar near-field test software correction method,probe formula method of correction,extrapolation test method and probe simulation method.Taking the Ku-band pyramid horn antenna as an example,the probe simulation method and extrapolation test method work best.The correction results can meet the needs of the actual project.