Simulate The Microwave Cavity Electromagnetic Field Distribution And Size Of The Structure To Optimize The Design,

Microwave oven is the most important aspect of microwave appliances. But the design of microwave oven still stays around the old kind design manufacturing mode of "design - trial - correct", which prolonged design time, increased design cost, and weaken the enterprise's competition ability. The emergence of electromagnetic simulation software provides a new mean to calculate and estimate field distribution characteristic. With software the precise calculation and function estimate can be carried out before the design stage, and reduces a great deal of design expenses. The electromagnetism field distribution can be viewed on internal parts and horizontal sections with colorful manifestation. Through a simulation to the structure, according to field distribution characteristic, structure of microwave cavity can be improved, making more microwave energy coupled into cavity. The main works of this dissertation are listed as following:The first chapter introduced the principle of microwave heating and the main parts of microwave oven.The second chapter introduced several theories concerning the design of microwave oven, incluing the theory of Finite Element Method, Resonate Cavity, Waveguide, and Impedence Matching. And some illustrations were made according to the actual problems in microwave oven design.The third, fourth and fifth chapters are the main parts of this dissertation. The third chapter studied several factors which have greater influence on the oven performance with simulation method. The trends of change were attained. These factors include magnetron model, waveguide, resonate cavity and glass turntable. In these factors the magnetron model has the greatest influence on the simulation result. In this dissertation, the model of the magnetron antenna was made as same as the actual size.The fourth and fifth chapters are innovations of this dissertation. Some judgment methods are put forward in the third chapter, including output power, efficiency, uniformity, drive axle melting, turntable bursting, waveguide Arcing. Then, comparisions between simulation and experiment on 25L and 28L ovens are carried on. And the feasibility of simulation method is testified. In addition, drive axle melting of 21L oven was solved in practical work.Two new flat microwave ovens, F17L and F20L, are designed with simulation method in the fifth chapter. Put forward the final cavity structures based on the simulation results. Agreement between simulation and experiment is good on the whole. The workability of the software in microwave oven manufacture is testified.