Simulation Modeling of the Distribution of Microwave Field Strength in the Grain Layer

To ensure quick prototyping and reduce the possibility of losses caused by errors at various stages of development and implementation of equipment for microwave heating of dielectric materials, the development and simulation of models is of particular importance. The aim of this work is simulation of a slotted waveguide grating for grain drying. The main task of the simulation was to ensure an even distribution of power through each slot. Simulation modeling was carried out using a specialized software package FEKO. To describe the model, an exact calculation method was used - the method of moments; the results were verified. The dependences of the antenna SWR on the width of the slots and the angle of rotation of the slots were investigated and optimal arrangement of slots was chosen. Simulation modeling of field distribution showed that placing the waveguides farther from the container leads to the alignment of the field inhomogeneity, but some part of the radiated power is lost in this case. As the calculation results showed, an increase in the distance between the waveguide and the container with grain did not affect the SWR of the waveguides. It should be noted that in a real situation, the wave character of the field is smoothed out due to heat transfer, which cannot be taken into account in the process of electromagnetic modeling. In addition, the entire spectrum of possible changes in the dielectric parameters of the grain should be investigated in order to analyze the process of wave propagation at high grain moisture. It is also advisable to consider other modifications of the slotted waveguide antennas, which can provide more uniform heating inside the container with grain.