A Full-polarization Scattering Matrix Measurement Method Based on Antenna Spatial Polarization Characteristic Analysis

As we all know, polarization is another way to obtain target characteristics besides time and frequency which expands the dimension of information acquisition. The polarimetric signature of a simple target can be obtained from its' scattering matrix, which shows the complete information of target. What's more, radar antenna is an important part of radar scattered radiation testing system, which is a polarization modulator in polarimetric measurement system. Its' polarimetric signature is a function of frequency and space location. Based on the static measurement of extended targets, The spatial polarization distribution of antenna is studied to improve the measurement accuracy of the full polarization scattering matrix. Firstly, research on the spatial polarization characteristics of common aperture antennas is carried out, analyzing the spatial polarization characteristics of rectangular antenna and constructing a spatial representation model of antenna polarization for scattering measurement. Then, studying the target scattering matrix measurement and proposing a scattering error transfer model based on antenna space polarization. Finally, according to the constructed polarization error transfer model, the polarization calibration error of the extended target is calibrated, this error is caused by the traditional calibration method which didn't consider the spatial polarization distribution of antenna. Then, the polarization scattering matrix is obtained after polarization calibration. This paper gives many simulations and actual results, which all demonstrate the validity of the method proposed above and achieve more accurate polarization characteristics of the target after getting rid of the impacts of antenna spatial polarization characteristic error. The method presented in this paper provides ideas for future analysis of more complex objects.