The Research Of Target's Radiation Characteristic In 8mm Wave Band

Microwave radiometry is a typical passive detection system, widely apllied in remote sensing and guiding areas. We actualize the passive detection on the foundation that things we observed get different radiation characteristic, so it is necessary and important to do research on radiation characteristic.There are two methods to do that. One is based on the theory while the other based on experiments. The theory method introduces a model that illustrates the relation between brightness temperature and some environment factors.The latter method is based on the statistics theory, that means we do experiments to know all the objects that we are interested in, then a database is setup ,we get the object information by comparing the data from the database with those measured.The frequency on which the radiometry works rely on the need of the detection, because the effect of the atmosphere, for example, the radiometry measuring the temperature of the atmosphere works at the frequency 50-60GHz, while this paper choose 36.4GHz in order to minimize the effect of atmosphere attenuation.This article will expatiate the theory method of radiation characteristic of objects in air, and we make different experiments on basis of the theory. Then this paper introduce H_plane sectoral horn ,a radiometry antenna that works at the frequency 36.4GHz. The directivity is calculated here ,with the help of HFSS(High Frequency Structure Simulator),at and we do experiments to validate the results that HFSS calculates.At last , the analysis and conclusion are given.