Solid Dielectric Film, Sheet Measurement Of Complex Permittivity

Microwave dielectric materials have been widely used in information and communication domain, which are used in the systems of microwave communication, electronic countermeasure and so on. Therefore it is highly significant to measure the electromagnetic parameters of medium materials, as knowing the dielectric materials'microwave characteristics is the most important factor in applications. As improvement of modern scientific technology, it is further and more and more accurately to measure electromagnetic parameters of dielectric materials.In this paper, the complex permittivity measurement of low-loss thin materials using a cylindrical cavity is researched. Based on the technique, a set of automatic system at X band is built. According to the frequency and the quality factor of the cylindrical cavity unloaded and loaded, the system can calculate the permittivityεr' and the loss angle tangent tanδof the thin materials being tested.The main research work includes:1. Through analyses of the correlative measurement technology and consideration of the characteristic of the measured materials, the method by cylindrical cavity is selected; Theory of resonant cavity is analyzed; Physical model is settled; The formulas are deduced.2. Feasibility of test model is discussed. Measurement is done to all of department of the system. Finally the whole measurement system is built. It realizes auto control by software designed with VC++.3. The thin samples are measured by the system at X band. And the analysis of uncertain is summarized.The result indicates that the method is correct, and the test system is reliable. Therefore, the test technique can be used for the rapid, credible, automate measurement of material parameters of dielectric medium, and it is also extraordinary practical.