HOM coupler design ---loop type v.1 Hongjuan Zheng, Fanbo Meng 20161214

3D model l11 l14

3D model l3 l2

3D model l5 cl tuning notch frequency

3D model dm the notch frequency depth c2t the notch frequency depth

3D model The notch frequencies of the two models are different. The transmission efficiency of the tube model goes worse than the coupler model. (under cut off frequency) Coupler with tube model is more practical ! -14.5dB coupler model -35dB cl cut off: TM01 1471MHz cut off:TE11 1126MHz coupler with tube model coupler model coupler with tube model

3D model Influence of the orientation of the coupling loop alpha Use rotatable flange Possibility to tune the notch frequency Tuning sensitivity almost linear in the range of small angle change

3D model alpha CST parameter sweep results are slightly inaccurate! number of data points 90000 angle=85deg f=616.28 S21=-116.06dB angle=90deg f=596.17 S21=-98.3dB CST parameter sweep results are slightly inaccurate!

3D model Influence of the insertion length of the coupling loop rin cut off frequency: TM01 cut off frequency: TE11 The longer insertion length rin, the better for HOMs rin does a great influence on the notch frequency Coupler kick?

3D model 100mm rin=15mm cl=55mm TM010 π mode: f=650.0046 MHz, Qe=2E+11

Conclusion Check the calculation model The damping for the fundamental mode is enough Possibility to tune the notch frequency according to the orientation of the coupling loop Next Thermal loss calculation Machined error analysis ……