Yu. I. Choni - Ph.D. (Eng.), Professor, Kazan National Research Technical University n.a. A.N. Tupolev - KAI. E-mail: tchoni@rambler.ru I. Yu. Danilov - Post-graduate Student, Kazan National Research Technical University n.a. A.N. Tupolev - KAI; Head of Department, JSC Academician M.F. Reshetnev Information Satellite Systems. E-mail: danilov@iss-reshetnev.ru

Development of methods and means of antenna pattern reconstruction based on measurements in the Fresnel zone, or in the near field under condition that chamber walls are of not highly anechoic quality is of great practical interest. Work in this area began thirty years ago and are developing rapidly till now being stimulated by progress in automated measurements and data processing. The paper discusses the issues related to the embodiment of the reference antenna method, which is based on a preliminary exami-nation of the illuminating field using a probe with a properly known pattern that rotates around the area reserved for the test antenna. The Illuminating field is approximated by convergent cluster of plane waves that allows one to represent the signal received by the antenna under test by the convolution integral of the antenna pattern and the spatial spectrum of the waves cluster. For a specific example, stability and accuracy of corresponding solutions are analyzed when the number of waves of the cluster varies within a wide range. It is shown that the limitation of this number by a rational value is not inferior to the use of regularization methods if the reconstruction accuracy is considered. Fields corresponding to the calculated wave clusters are depicted by cartograms for the two-dimensional case when measurements are carried out in the plane and the geometry is the following: the antenna under test is of 10λ in length, and the illumination source is removed from it at a distance of 15λ. Outside the area of measurements, the field has unusual curious relief. The results of reconstruction are compared for cylindrical and spherical illuminating waves.

 

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