一种太赫兹机电波导开关的设计

The Designing of A Terahertz-band Electromechanical Controlled Waveguide Switch

针对太赫兹频段卫星通信系统对信号传输及切换的需求,设计了一种工作于114 GHz^173 GHz频段的无间隙C型机电波导开关。首先,采用等效电路理论进行传输线匹配设计,并分析了波导口宽边和窄边错位对电压驻波比的影响;之后,依据导体损耗理论分析了金属壁电导率对插入损耗的影响,并运用HFSS软件对通道长度、表面粗糙度等因素进行参数敏感性分析;最后,提出了一种新型扼流槽加载方式。结果表明:开关的驻波比与弯曲半径成正比,考虑到定子强度及小型化设计,应选择合适的弯曲半径;采用银镀层有利于提高插损指标,且在太赫兹频段,为降低插入损耗,微波通道的表面粗糙度应优于0.8 um。最终,在114 GHz^173 GHz频段,开关的电压驻波比小于1.1,插入损耗小于0.45 dB,隔离度大于80 dB,耐功率为3000 W,满足设计要求。

In order to meet the requirement of signal transmission and switching in terahertz-band for satellite communication system,a gapless c-type waveguide switch operating in 114~173 GHz frequency band is designed.Firstly,the equivalent circuit theory is used to design the matching of transmission line,and influence of the wide and narrow edge dislocation of waveguide port on the voltage standing wave ratio(VSWR)is analyzed.Then,the influence of metal wall conductivity on insertion loss is analyzed according to conductor loss theory,and HFSS software is used to conduct sensitivity analysis for parameters of channel electrical length and surface roughness.Finally,a new method of loading choke groove is proposed.The results show that VSWR of the switch is proportional to the bending radius.Considering the strength of stator and miniaturization design,appropriate bending radius should be selected;Silver coating is beneficial to improve the index of insertion loss,and in terahertz-band,the surface roughness of microwave channel should be better than 0.8um in order to reduce insertion loss.Finally,in the 114 GHz^173 GHz frequency band,the VSWR of the switch is less than 1.1,the insertion loss is less than 0.45 dB,the isolation is greater than 80 dB,and the power resistance is 3000 W,which meets the design requirements.