Research on New Methods of Improving Microwave Oven Heating Uniformity

随着社会进步和微波能利用技术的发展，微波炉的使用越来越普及。因微波具有良好的穿透性，能直接将微波能量送入被加热物体内部，实现了对物品内部和外部同时加热，因而极大地缩短了加热时间，提高了加热效率。此外，微波加热食品既不产生油烟、一氧化碳等有害物质，又能够最大限度地不破坏食品的营养成分，真正体现了现代人健康饮食的理念。 本文介绍了微波炉的发展过程，突出了传统微波炉加热不均的缺点及现用的常规克服方法：一种是在微波炉加热腔底部放置由电机带动旋转的食品托盘，另一种是在微波炉加热腔顶部放置由电机带动旋转的场搅拌器。此两种方法能在一定程度上克服微波炉加热的不均匀性，但都需要在微波炉加热腔中放置额外器件，给...Along with social progress and continuous improvement of microwave energy utilization technologies, the use of microwave ovens is becoming increasingly popular. Because of the good penetrability of microwave, microwave energy can be sent into the objects directly, and food can be heated from both internal and external. Thus, the heating time is greatly reduced and the heating efficiency is improve...学位：理学硕士院系专业：物理与机电工程学院物理学系_无线电物理学号：1982008115301

Automatic Measurement Method of the Resonant Frequency of Cylindrical Dielectric Resonator with Holes

从求解MAXWEll方程本征值出发,采用MATlAb中PdE工具箱,借助可二维作图的开槽圆柱谐振器,计算出有孔圆柱介质谐振器的谐振频率。求解结果与矢量网络分析仪测量结果吻合,误差在千分之四以内。且该有限元法计算软件采用MATlAb编写,可方便地被调用于矢量网络分析仪的VEE测试软件中,较好解决有孔及变形圆柱介质谐振器的设计、测量和微调等问题,特别是矢量网络分析仪的快速自动测量中。One method of calculating the resonant frequency of cylindrical dielectric resonant with holes is introduced.The method is based on the solution of eigenvalue of the Maxwell equation,and the resonant frequency of cylindrical dielectric resonant with holes is solved by applying the PDE tool box in the Matlab.Compared to the measurement results of the PNA,the error of the method is not more than 0.4%.The numerical method can be programmed by Matlab,and then can be applied conveniently in the test software VEE of the PNA.Thus,the complementary advantages of the method are very beneficial for the design of the resonant frequency of cylindrical dielectric resonant with holes and the deformation cylindrical dielectric resonant,and also can be used for solving many other problems,such as online automatic measurement of the resonant frequency of cylindrical dielectric resonant with holes and the deformation cylindrical dielectric resonant.福建省自然科学基金资助项目(2008J0031

Fast and New Measurement System of Temperature Coefficient for Open Dielectric Resonator

谐振频率温度系数是微波介质陶瓷材料的重要性能参数之一,文中提出了一种微波介质谐振器温度系数的新型快速检测方法,并介绍了系统的测试原理、电路结构和软件组成。该系统对微波陶瓷材料温度系数进行测量时,所产生的系统误差、人为误差最小,可实现精确和快速检测。Resonant frequency temperature coefficient is an important property parameter of the microwave dielectric ceramic materials, a fast and new measurement system for temperature coefficient of microwave dielectric resonator is presented. The principle and circuits as well as,software of measurement system is introduced. It is shown that the system has low system error and man-made error, and can measure the temperature coefficient of microwave ceramic materials accurately and fast.国家863计划资助项目(2001AA325100);; 福建省自然科学基金计划资助项目(J0650016