A large-volume and high-efficient microwave plasma source with planes slotted antenna

The industrial applications of microwave plasma is restricted by small volume and low efficiency. It´s necessary to design a large-volume and high-efficient microwave plasma system at atmospheric pressure, whether in the theoretical research, or in industrial applications. A novel large-volume microwave plasma source with planes slotted antenna has been developed and can directly generate and sustain air plasma at atmospheric pressure with relatively low power input. Plasma chamber is assembled by the upper and lower metal planes and two adjacently parallel rectangular waveguide resonators with axial slots on its inner side. Microwave electromagnetic energy is coupled from the parallel rectangular waveguides through regularly positioned resonant coupling slots into the plasma rectangular chamber of 59 cm in length, 10.9 cm in width and 4 cm in height. The location and size of the slots were determined by the electromagnetic numerical simulation. The geometrical properties of the microwave plasma source were optimized to produce high-amplitude, large-scale and uniform electromagnetic field distribution. The calculated fields distribution fit perfectly to those measured inside the plasma rectangular chamber without plasma. Potential industrial applications of this microwave plasma source are for material synthesis and sterilization.