摘要:针对微放电过程中的电子累积效应,探索二次电子累积对微波部件传输特性的影响,提出二次电子累积"等效介质"的理论模型,通过将电子累积等效为"特殊介质",从介质的角度探索电子累积对传输特性的影响,推导得到不同电子累积密度所形成不同"等效介质"的相对介电常数.仿真和计算结果表明,微放电过程中,电子累积密度从0增长至1016/m3数量级时,传输特性基本不发生变化;但是当电子累积密度达到1017/m3数量级时,阻抗变换器的通带内回波损耗恶化了15 dB;随着电子累积密度继续增大,"等效介质"对电磁波的反射迅速增强,微波部件的传输特性急剧恶化;在电子累积密度达到4×1017/m3时,电磁波在阻抗变换器中的传输处于完全截止状态.为了进一步探讨导致传输特性恶化的深层原因,发现在电子累积密度达到4×1017/m3时,在2.5~5 GHz的频率范围内,电子累积形成"等效介质"的相对介电常数呈现为负值,电磁波传输截止,"等效介质"表现出单负介电常数超材料的特性,即导致阻抗变换器传输特性恶化的原因是单负介质材料的形成.研究有益于更深入地认识微放电形成过程中的深层物理机理及其对宏观电性能的影响,为寻求更加有效的抑制方法提供理论依据.%The relationship between the accumulation of multipacting electrons and the variation of the transmission properties in microwave components was studied.An equivalent media model was proposed to describe the electron accumulation during multipactor,where effects of the electrons'accumulation were approximated as a media with special relative permittivity. The value of the special relative permittivity was calculated equivalently corresponding to the electron density. Simulation and calculation results indicate that the transmission properties of the microwave components remain unchanged when the density of electrons increased from 0/m3 to 1×1016/m3 during multipactor.However,the return loss in the pass band frequencies dropped 15 dB when the electron density reached 1 ×1017/m3.As the increasing of the electron density, the reflection of electromagnetic wave caused by"equivalent media" increased rapidly which made the transmission properties of the microwave components deteriorates sharply.The simulation was coincide with the results of theoretical analysis,which indicated that the transmission was even cut off when the density of electrons increased to the magnitude of 4×1017/m3.In addition,when the electron density reached 4×1017/m3 (in the frequency range of 2.5~5 GHz),the relative permittivity of the"equivalent media"was negative and the transmission cut off. This research is helpful to understand the mechanism and the electrical characteristics changes of microwave components due to multipactor,providing an effective theoretical principle for multipactor suppression.