1. A.Lounine, T.Higo
H60VG3K1 Couplers Design.
MDK-2001
CERN
Switzerland

2. Input Coupler Output Coupler r = 0.5 10.12 10.35 r = 0.5 T0m= 5
Matching Cell
r = 0.5
T0m= 5
2A0m= 15.52
2B1m= 24.2
T53m= 4.8
2A53m= 13.82
T1=
2A1=
2B53m= 23.2
Matching Cell
All dimensions are at 20C
Calculation frequency is GHz

3. Equidistant Manual Mesh Generation
Tetrahedras ~ Azimuth rotation step = 2 degree
! Automatic ANSOFT mesh generator produces too much nonuniform mesh;
! As a result – poor convergency, poor field’s output

4. Tipical HFSS simulation for output coupler
* E[V/m] is normalized for 1 Wt input power (a quarter geometry!)

5. Output Coupler Surface Fields
~3.5% iris field enhancement
Surface path
* E[V/m] is normalized for 1 Wt input power (a quarter geometry!)

6. N.Kroll Method of Reflection and Phase Advance Simulation Results
Input Coupler
Output Coupler

7. Network Analizer Experemental Setup S11, S21 RF Load HP 8510C
Matching cell
Reflection = S11 + S12
S22, S12

8. Input Coupler. HFSS&Experemental Results*
* Experimental results are shifted to the calculation conditions (20C, vacuum)

9. Output Coupler. HFSS&Experemental Results*
* Experimental results are shifted to calculation conditions (20C, vacuum)
** Due to technical mistake the measurement was done with wrong RF-load diameter

10. Base Parameters Tolerances, HFSS Simulations
Output Coupler.
Base Parameters Tolerances, HFSS Simulations

11. Final Remarks.
H60VG3 is low group velocity structure , therefore couplers bandwidth is very narrow.
The mesh parameters are very critical to final results.
The 3D Mesh parameters were obtained from 2D analog.
The phase advance was strictly cheked at each calculation step (<0.5 degree).
Hook-Jeevs method + frequency sweep were used for couplers optimization.
The measurement results are in good agreement with the calculated ones.
The most sensitive dimension is B (outer radius). The accuracy of Bn dimensions
should be better then 2 μm.