Study on Electromagnetic Coupling-Type Microwave Heating Systems with Repeaters

We propose electromagnetic coupling-type microwave heating with repeaters for the purpose of extending microwave heating area. We investigated simultaneous microwave heating for two samples, whose materials are ethanol or water in a glass test tube, via 3D electromagnetic simulations. The repeater was more effective in distributing energy evenly to each sample for heating ethanol than water. We simulated heating of water at 20 °C, changing the inner radius of the test tubes D. In the case D is equal to half the value of wavelength in water, the repeater acted as a resonator. This is expected to result from about 180° phase advance while microwaves reach the edge of the sample from the other. In conclusion, it is a good way that D is nearly equal to half the value of wavelength in samples so that the repeater acts as a resonator and distribute power to each sample evenly.