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

2. 3D model
l11
l14

3. 3D model l3 l2

4. 3D model l5 cl
tuning notch frequency

5. 3D model dm
the notch frequency depth
c2t
the notch frequency depth

6. 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: TM MHz
cut off:TE MHz
coupler with tube model
coupler model
coupler with tube model

7. 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

8. 3D model alpha CST parameter sweep results are slightly inaccurate!
number of data points 90000
angle=85deg
f=616.28
S21= dB
angle=90deg
f=596.17
S21=-98.3dB
CST parameter sweep results are slightly inaccurate!

9. 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?

10. 3D model
100mm
rin=15mm
cl=55mm
TM010 π mode:
f= MHz, Qe=2E+11

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
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Thermal loss calculation
Machined error analysis ……