S波段大功率Y结式波导隔离器设计与性能

Design and performance of S-band Y-junction waveguide isolator

相对于差相移式波导隔离器,Y结式隔离器具有尺寸小、重量轻的优点,但其功率承受能力不足。对此,采用高场工作以避免高峰值功率下的非线性损耗效应,并利用结区分层结构降低功率密度、提高铁氧体基片的热传导速率。在具体设计中,采用合适的磁化工作点以兼顾损耗指标和稳定性并尽可能降低铁氧体基片的厚度、增大基片之间的空气间隙。HFSS仿真设计结果和实测性能十分吻合,器件工作于S波段,插入损耗小于0.18 dB,峰值功率承受能力为3 MW,平均功率承受能力为4 kW。

Y-junction waveguide isolator is compact and light-weight but inferior in high power handling capability compared with differential phase-shift isolator.To improve power handling capability,biasing the dc magnetic field above resonance region to avoid nonlinear loss effect and by using multilayer junction structure to reduce the power density and improve the heat transfer velocity of the ferrite disks.On the design,adopting appropriate bias magnetic field give consideration of insertion loss and stability,and it is necessary to make the ferrite disk as thin as possible and have large air gap between ferrite disks.The test results meet with electromagnetic simulations performed using Ansys HFSS,verifying the design method.The isolator features work frequency of S-band,insertion loss≤0.18 dB,peak power≥3 MW,and average power handling≥4 kW.