Near-field Measurement, Graphic Extrapolation Of The Near-field-diameter And Antenna Holography Diagnosis Research

In this thesis, the main research work is focused on near-filed measurement and near-field holographic diagnoses. The concept about near-field aperture extrapolation is presented. This idea is realized by employing Matrix-Pencil method.The main work is as follows:1. The relationship between near-field and far-field is analyzed and traditional probe compensation is discussed. A program of simplified probe compensationmethod is completed.2. The wavelet algorithm is used to reduce the measurement noise.3. Different methods in near-field aperture extrapolation are discussed. It is found that the Matrix-Pencil(MP) method is the best one for this purpose. The capability of extrapolation is also investigated.4. A technique about transformation from near-field to aperture-field is applied to diagnose aperture. This method is based on plane-wave spectrum. The amplitude and phase distributions of aperture field are obtained from the detailed analyses of the near-field measurements.5. Based on the mixed programming with the MATLAB language and the VC++ language, the package of near-field data processing and the far-field measurement system are designed. Near-field data processing package can process all the output data from AV3635 antenna measurement system conveniently. Far-field measurement system can automatically fulfill almost all the far-field measurement. Now this system is applied for the practical use.