Periodical metal cylinders for improving heating uniformity of small batch materials in microwave applicators with rotating turntables

Abstract

Microwave applicators with rotating turntables have been widely applied in many fields, but the heating non-uniformity still limits the further applications. Specifically, when microwave applicators are used to process small batch materials, materials have to be away from the center of rotating turntables, where the problem of heating non-uniformity is more prominent. In order to overcome this difficulty, this paper presents a novel periodical metal cylinder structure to improve the heating uniformity for microwave applicators. With the proposed periodical metal cylinders being placed beneath rotating turntables, electromagnetic fields can be well adjusted, thus improving the heating uniformity. To demonstrate the heating uniformity with the proposed structure, the heating process of the arrays of two and three potato slices in a practical microwave applicator is simulated by the finite element method, respectively. The results show that both the heating uniformity of the two and three potato slices can be improved, which is validated by experiments. Furthermore, the results show that the temperature similarity among the processed potato slices with the proposed structure is better than that without the proposed structure.*

0.5kWatt 2.45 GHz GaN‐based microwave heating system design with active phase control

“…The conventional MW heating system receives power from a power supply, generates a signal using a magnetron having oscillator properties, and then applies it to the MW applicator through a waveguide. Since the magnetron oscillation times are different, the input phase of the magnetron at the MW heating system with multiple magnetron sources cannot be matched 11–17 …”

“…Since the magnetron oscillation times are different, the input phase of the magnetron at the MW heating system with multiple magnetron sources cannot be matched. [11][12][13][14][15][16][17] Figure 1 shows the proposed 2.45 GHz GaN (gallium nitride)-based MW heating system including overall configurations and antenna deployment. In Figure 1A, THE proposed system consists of two 2.45 GHz signal generators, two electrically controlled phase shifters, two 250-W GaN amplifiers, two metal patch antennas, and the MW applicator with heating material.…”