基于HFSS模拟的陶瓷管配置对微波液相放电电极匹配影响研究

Effect Study of Ceramic Tube Figuration on Electrode Matching of Microwave Discharge in Liquid Based on Simulations Using HFSS

陶瓷管是微波液相放电电极中难以被其他物质所替代的重要组成部分,研究陶瓷管对微波液相放电电极匹配的影响具有重要意义。为此,在内外电极尺寸一定的条件下,以陶瓷管自身长度、陶瓷管和内电极的相对位置以及液体的相对介电常数作为变量,研究了驻波比(SWR)和用HFSS软件模拟的电场强度随这些变量的变化。结果表明:在乙醇和甲醇中,当陶瓷管位于内电极下方时,2者之间的距离越大,SWR越小;随着陶瓷管长度的增大,SWR呈先增大后减小趋势。在纯水中,当陶瓷管位于内电极上方时,随着陶瓷管长度的增大,SWR呈减小趋势;当陶瓷管不高于内电极时,SWR呈先减小后增大趋势。SWR最小值的获取条件与模拟电场强度最大值的获取条件不同,只有当陶瓷管平行于内电极时,模拟电场强度才能取得最大值。在电极匹配过程中,需要兼顾SWR和电场强度。

Ceramic tube is irreplaceable part of electrode for microwave discharges in liquid, so it is of great significance to study ceramic tubes for matching the discharges＇ electrodes. To this end, using inner and outer electrodes with fixed figure, we took length of ceramic tube, relative position of inner electrode to ceramic tube, relative dielectric constant of liquid as the target variables to study their variation＇s impact on standing wave ratio（SWR） and electric field intensity（simulated using HFSS）. The results show that in ethanol and methanol, with increasing distance of ceramic tube to above inner electrode, SWR decreases; when the length of ceramic tube increases, SWR firstly increases and then decreases. Meanwhile, in pure water, when the ceramic tube locates above the inner electrode, SWR decreases with the length of ceramic tube; otherwise SWR firstly decreases and then increases with increasing length of ceramic tube. Moreover, the condition for obtaining minimum SWR is different from that for obtaining maximum simulated electric field intensity： the maximum simulated electric field intensity appears only when the ceramic tube is parallel with the inner electrode. When matching the electrodes for microwave discharges in liquid, it needs to strike a balance between SWR and electric field intensity.