Study Of Low-power Microwave Microplasma Based On Microstrip Split-ring Resonator

Low-power microwave plasma technology based on microsystem is a high-tech developed in recent years, which is integrated with microelectronic technology, microwave technology and plasma technology. Its basic idea is to excite a small size plasma on micro-strip with low microwave power. With the extensive application of MEMS technique, the small plasma source based on the MEMS technique is drawn more attentions. The plasma source is characteristic of small size, portability and operation at room temperature and atmospheric pressure. And the plasma source has many applications on chemical analysis, micro-chemical treatment and particle detection.On the basis of theoretical analysis, several microstrip split-ring resonators which resonate at2.45GHz are presented. Firstly, an alumina ceramics is used as dielectric substrate,, and three structures are introduced, including ordinary parallel edge structure, point edge structure and round edge structure. The research shows that more uniformly distributed electromagnetic fields are available around the round edge structure, and the plasma is excited more easily.Secondly, three different materials (alumina ceramics, glass and silicon) are chosen as dielectric substrate, and the round discharge structures of MSRR with gap width of0.1mm,0.05mm are analyzed respectively. It is discovered that the stronger electromagnetic fields can be excited with smaller gap.In order to obtain stronger electric fields, dielectric substrate is dug up at the gap. A12O3-ceramic MSRR with small gap and Glass_PTFEreinf MSRR with large gap are simulated. The results show that the resonant frequencies increase, and the strength of electric fields increase at the same time. The MSRR packaged with the glass cover is simulated. The research shows that resonant frequency turns lower and the electric fields turns stronger. It is demonstrated that the electromagnetic energy is concentrated in the glass tube.Finally, one-dimensional reactions of plasma excitation are simulated with COMSOL. The results show that the microplasma is excited more easily when the pressure is higher, the electron density, the ion density and the electric potential between the gap are higher. The MSRR is fabricated, and the experimental results have good agreement with the simulated results.