ДИАГНОСТИКА АМПЛИТУДНО-ФАЗОВОГО РАСПРЕДЕЛЕНИЯ С ИСПОЛЬЗОВАНИЕМ МЕТОДА ФОКУСИРОВКИ ПРИ ИЗМЕРЕНИИ В БЛИЖНЕЙ ЗОНЕ ИЗЛУЧЕНИЯ
Authors: Седельников Ю.Е. , Тутьяров Н.А. , Шагвалиев Т.Р. 
Published: February 2025

Рассмотрены вопросы организации измерения амплитудно-фазового распределения антенн методом фокусировки. С целью повышения точности измерений предлагается использование датчика ближнепольной измерительной системы с равномерной диаграммой направленности. Для формирования равномерной диаграммы направленности (ДН) предлагается конструкция датчика с дополнительными вставками, выполненными из метаматериала.

Introduction. Currently, the development and testing of special-purpose antennas often pose a need to control their aperture distributions with the use of the general-purpose equipment. Despite the significant achievements in this area, antenna diagnostics is still topical, especially due to the use of hybrid-mirror antennas in state-of-the-art active antenna arrays (AAAs). For these purposes, a large number of different techniques have been proposed, developed, and are being used. First of all, these are direct measurements of amplitude-phase distributions (APD) in the antenna aperture. There are a large number of methods for measuring these values and devices for their implementation. For instance, there are a lot of Patents issued in the Russian Federation and the USSR: No. 2267795, 2254585, 2275644, 1786453, 1770918, 1693568, 15997788, 1223170, 1229644, 1146611, 1415203, etc. The aim of the research. Carrying out the indicated measurements directly in the aperture or at least at a small distance from the antenna is technically impossible in some cases that are important for practice. For these cases, there were proposed methods that are based on measuring the parameters of the electromagnetic field of the antenna in the near field zone with the subsequent measuring the desired AFD by the appropriate data processing. Currently, not only are developed methods for measuring radiation patterns in the far field zone, but also the relevant software and hardware. Practical significance. The application of the procedures for processing the measured data according to the modified focusing method allowes one to measure the APD of the tested antenna with satisfied reliability for a number of applications. However, the accuracy of measuring the amplitude-phase distribution also depends on the characteristics of the sensor of the near-field measurement equipment. Since the antenna pattern of antenna-sensor is non-isotropic, measurements at different points of the scanning plane are typically performed under nonequivalent conditions. This leads to a decrease in the accuracy of the APD reconstruction of the tested antenna. To measure the antenna pattern of the antenna-sensor with the indicated properties, it is reasonable to use the proposed antennas in the form of an open end of a rectangular waveguide with an inset made of MNG-type metamaterial. Conclusion.It was found that in order to achieve the best results, it is reasonable to use an antenna-sensor of a near-field measurement system with a radiation pattern as uniform as possible within the virtual aperture. It was shown that the widening of the antenna pattern of the proposed antenna in the form of an open end of a waveguide with a metamaterial inset with negative magnetic permeability becomes possible when it is installed at a distance of dv⁄ (λ) = 0.5 ... 1 wavelength or less.