微波均衡器中微调螺钉的作用研究

Study on the Effect of Trimmer Screw in the Microwave Equalizer

微波幅度均衡器是由吸收型同轴谐振腔作为其基本结构单元多级级联实现,谐振频率主要通过改变腔长和探针插入深度来调节,同时改变微调螺钉也能影响谐振频率.论文从理论上阐述了微调螺钉对同轴谐振腔谐振频率的影响程度,在电场占优的地方,螺钉插入越深,降低谐振频率;反之,在磁场占优的地方,螺钉插入越深,增大谐振频率.并利用HFSS软件仿真子结构谐振腔的电磁场分布,从而确定微调螺钉的位置.根据微调螺钉对谐振频率影响的规律,采用补偿调试的方法还能减小温度对谐振频率的影响,同时,微调螺钉还能抑制寄生模的产生.

The microwave equalizer is interconnected by several single substructures, which is the absorptive coaxial transmission line coaxial cavity resonator, The frequency of cavity resonant is changed mainly with the length of cavity resonant and the depth of the probe, and also with the trimmer screw. The paper gives the reasonable explanation from the electromagnetic theory, the different location of trimmer screw can give the different influence of resonant frequency, that is deepening the trimmer can decrease the frequency when it is in the electrical field dominant position, and vice versa. HFSS （High Frequency Structure Simulator） software is used to simulate the electromagnetic field distribution of the cavity, and the location of trimr mer screw can be determined. The method of trimmer screw compensation tuning can be used to diminish the effect of temperature on resonant frequency, and trimmer screw can restrain parasitic modes electromagnetic wave birth.