一、引言 非电量微波检测技术的理论与实践在国内外已有较广泛的研究。不少著名学者如Kalinski.J,Kraszeweki.A等人的论文著作及专利就超过一百多篇,他们在微波测湿应用方面的贡献是很大的。有鉴于此,早在1980年,国际微波能会议在波兰召开,出版了微波测湿专集,并由Kraszewski博士担任主编。对介电常数模型;单参量副载波调制及零差检波系统;双参量消除密度及厚度影响的理论及实验;斩断副载波调制技术新理论等方面都作了较多的论述。国外研制的多种微波测湿仪表已广泛用于精炼、化工、电气、石油、煤炭、纺织、造纸、建材、农业、食品、制药、木材、陶瓷等工业生产方面。测 I. INTRODUCTION The theory and practice of non-power microwave detection technology have been widely studied at home and abroad. Many well-known scholars such as Kalinski.J, Kraszeweki.A and others have more than one hundred papers and patents, and their contribution to the application of microwave measurement is great. In view of this, as early as 1980, the International Conference on Microwave Energy held in Poland, published a microwave moisture test album, edited by Dr Kraszewski. The discussion on dielectric constant model, single-parameter subcarrier modulation and zero-difference detection system, theory and experiment of double-parameter elimination of density and thickness influence, new theory of cutting off subcarrier modulation and so on are all discussed in detail. A variety of foreign developed microwave measuring and wetting instruments have been widely used in refining, chemical, electrical, petroleum, coal, textile, paper, building materials, agriculture, food, pharmaceutical, wood, ceramics and other industrial production. Measurement