Research On Key Technology Of Extrapolation Antenna Gain Measurement

In recent years, microwave antenna working frequency is expanded, and the number of antenna types is increasing, but the high precision measurement of microwave antenna is a difficult technical problem. In order to improve the accuracy of the antenna measurement, National Institute of Metrology established the first high accuracy extrapolation antenna measurement standard equipment in April 2015.However, the measurement principle of the extrapolation antenna measurement,extrapolation antenna gain measurement method, core algorithm for extrapolation antenna gain measurement, antenna gain measurement uncertainty evaluation and experiment study on millimeter wave standard antenna gain measurement are the technical problems that needed to overcome at this stage. Therefore, researches on these technical problems are carried out in this paper , the main research contents are as follows:(1) Firstly, this paper introduces the extrapolation antenna measurement standard equipment, studies the extrapolation antenna gain measurement theory and measurement principle deeply and puts forward a novel extrapolation antenna measurement, strict measurement of antenna gain is extrapolation expression.(2) The core algorithm of extrapolation antenna gain measurement is studied in this paper. The innovation lies in the design of antenna mutual coupling suppression filtering algorithm, fitting algorithm of power series expansion and impedance mismatch correction algorithm, and a calculation model of the antenna gain at any distance is proposed. In addition, an operation interface of extrapolation antenna gain measurement is designed for measurement convenience.(3) The more reasonable uncertainty evaluation model is developed for the ten key uncertainty parameters during extrapolation antenna gain measurement, and the strict uncertainty evaluation method is made for each uncertainty sources, in order to provide a reasonable uncertainty evaluation results for the participation in international comparison.(4) The experiment research on the X band and W band standard horn antenna gain measurement is carried out basing on the theory and the core algorithm of extrapolation antenna gain measurement method. And the extrapolation of antenna gain measurement procedures are described in detail, thus the absolute antenna gain at arbitrary distance is obtained,and the corresponding gain measurement uncertainty summary table is given. In addition, the experimental study on W band high frequency standard antenna is carried out using 2m three antennas method,6m three antennas method and extrapolation technology, and then comparative analysis of the gain from these three antenna test method is made in this paper.