Research Of Antenna Used For Millimeter-Wave Imaging

Millimeter-wave focal plane array imaging system is based on the difference between objects in the millimeter-wave radiation, choosing appropriate millimeter -wave radiation frequency, polarization and beam angle of incidence, through antenna collecting millimeter-wave radiation energy of target and background, generating the image of reflecting objectives and background radiation characteristics, thereby identifying different types of objectives. Millimeter-wave focal plane array imaging system will combine electric and mechanical scanning, solve the problem of low resolution using mechanical scanning and unidentified real-time imaging.One of the key technologies of millimeter-wave imaging system is improving the resolution. The ellipsoid lens antenna in this paper is different from lens antenna and rotating dish antenna, it has dual focus structure, can focus the energy from one focusing point to another focusing point. Therefore, we can reduce the sensitivity of the receiver, improve of the resolution of the imaging system.First, this paper briefly introduces the key technologies of blackbody radiation and meter-wave principle imaging, and the difference between ellipsoid antenna and traditional focusing antenna. From the basic concept of focusing, this paper calculates Fennel zone radiation field of uniform radiation round caliber. Using MATLAB, this paper draws characteristic curve of different caliber but same focal length and same caliber antenna but different focal length focusing antenna, concludes certain regularity of focusing energy and scope.Secondly, this paper uses statistical methods to study ellipsoid conjugate imaging, and uses MATLAB to obtain the results with statistical characteristics. It can approximately express its imaging law. Then this paper explores the ellipsoid focusing properties at different dimensions, and concludes certain regularity, selects better ellipsoid with focusing properties, analyzes the characteristics of its partial focusing.Finally, the paper uses CST-Microwave Studio software simulates the return loss of ellipsoidal antenna, observes field on the focusing surface using the probe, determines its focusing radius of 3 dB and the focusing position under the circumstance of feed and biased focusing, compares it with the conjugate imaging statistical results.