微波介质材料的介电常数的测量，由于其具有和航空航天、新材料的研制、卫星遥感以及微波通信等方面密切相关而引起人们越来越多的关注，同样微波技术也得到了发展和应用。
The gauging of dielectric constants in microwave dielectric materials has stirred up more and more attention because of its closely related connection with the aerospace industry, innovative material development, satellite remote-sensing and microwave communications; and similar attention is also focused on the development and application of microwave technology.
本文介绍了微波谐振腔的基本原理、微波谐振腔基本指标，具体阐述了矩形微波谐振腔结构、最基本的模式矩形谐振腔 模和 模的场结构，以及微波谐振腔微扰理论和具体的腔内介质微扰，从而整理出介电常数测量的一般理论即微波谐振腔微扰法测量介电常数的理论方法。表明这种非接触式测量理论具有操作相对简单、所需样品量少、计算精度高、应用范围广，尤其适合于低损耗介质介电常数的计算。
This article explains the basic principles and essential index of microwave cavity resonator and specifically describes the structure of rectangular shaped microwave cavity resonator, and the most basic mode and mode field structures, as well as the perturbation theory of microwave cavity resonator and the specific dielectric perturbation in its cavity, so as to sort out a general theory for the gauging of dielectric constants, in other words, a theoretical methodology for gauging dielectric constants by applying the microwave cavity resonator perturbation method. This article indicates that this non-contact mode gauging theory has the advantages of simple operation, fewer sample requirements, high precision calculations and wide application scope, particularly suitable for the calculation of dielectric constants of low loss dielectric.