W波段高功率铁氧体开关的研制

Design of a W-Band High-Power Ferrite Switch

毫米波频段具有波长短、频率高、带宽宽等优势,毫米波器件的需求日益迫切。然而因要求小尺寸且受限于工艺水平,毫米波器件实现难度大。文中将折叠双T、差相移段、电桥依次通过法兰级联的方式辅以控制电路,实现了W波段高功率铁氧体开关的切换;通过优化器件匹配结构,解决了加工精度受限问题;通过简化铁氧体样品,在可操作范围内实现了90°差相移,最终实现了8 GHz大带宽、单级损耗小于2 dB、驻波比小于1.2、隔离度大于13 dB、开关切换时间3 ms左右的差相移式开关。对3个单级开关进行级联、调试并改进控制电路,可在W频段8 GHz的带宽内,实现驻波比小于1.2、插入损耗小于5.9 dB、隔离度大于52.9 dB的优良性能,接入雷达整机后的开关时间为1.5 ms,耐功率1.2 kW。

The millimeter wave frequency bands,especially the W-band frequency,having the advantages of short wavelength,high frequency and wide bandwidth,become increasingly widely used.However,due to their compact sizes and limited accuracy of current manufacturing technology,the millimeter wave devices are difficult to realize.The W-band highpower ferrite switch introduced in this article is switched with a control circuit by folding the double-T,differentiating phase shifter and concatenating 3 dB bridges.Through optimizing the device matching structure,the problem of limited manufacturing accuracy is overcome.Meanwhile,by simplifying the ferrite sample,a 90° phase shift is achieved within the operable range.As a result,the switch realizes the features of a large bandwidth of 8 GHz,less than 2dB single-stage loss,less than 1.2 standing wave ratio,larger than 13 dB isolation and a 3 ms switch time at a W-band frequency.Furthermore,through cascading and debugging three single-pole switches inside,and upgrading the control circuit,the W-band switch introduced in this article realizes quality features of less than 1.2 standing wave ratio,less than 5.9 dB loss and greater than 52.9 dB isolation within the bandwidth of 8 GHz in the W band.After integrated into radar system,its switch time is 1.5 ms,and the withstand power is 1.2 kW.