8/24/2015Pengda Gu, Structure Meeting Study on 30GHz Pulse Compressor 1.Simulation of a multi-cavity RF pulse compressor using a coupled resonator model 2.Design of the multi-mode SLED-II type pulse compressor 3.Design of the components of 30GHz pulse stretcher for CTF2

8/24/2015Pengda Gu, Structure Meeting 1.1 The model From this model, we can get the following equation

8/24/2015Pengda Gu, Structure Meeting 1.2 Steady state or frequency domain solutions For uniform coupled resonators where every cell is the same and cell number is very large Fig 2 Dispersion curve The numerical solution of the eignmodes of a 16-cell coupled resonators.

8/24/2015Pengda Gu, Structure Meeting 1.3 Time domain solutions and optimization Quasi steady-state Simulation results of 7 cavities a. The Q factor of all cavities is

8/24/2015Pengda Gu, Structure Meeting Fig 3 Output waveform before optimization Fig 4 Output waveform afteroptimization

8/24/2015Pengda Gu, Structure Meeting b. With low Q factor cavities Fig 5 7 cavities with 3 low Q cavities cavity arrangement HLHLHLHHLLHLLHHLLLLLHLHLHLHLLLHLHLL efficiency60.8%48.3% 43.8%(beta=8)44.4%(beta=8)

8/24/2015Pengda Gu, Structure Meeting Other simulations Fig 8 5 cavities with 2 low Q cavities Fig 9 9 cavities with 4 low Q cavities Fig 6 Output waveform of 8 cavities Fig 7 8 cavities with 4 low Q cavities

8/24/2015Pengda Gu, Structure Meeting 1.4 Conclusion a.RF pulse compressors with multi cavities can provide better output waveform than SLED. b. The efficiency is still not so good, around 60%. c. There is phase variation in the output pulse. d. The frequency tolerance as simulated in the 7-cavity case is too tight, which is about 0.001%.

8/24/2015Pengda Gu, Structure Meeting 2.Design of the 30GHz multi-mode SLED-II type pulse compressor (Based on the NLC multi-mode SLED-II approach) Input Output Rectangle TE10 to Circular TE01 Mode converter Iris Mode Preserving taper Cutoff for TE02mode Dual mode pipe Reflective TE01 TE02 Mode converter And tuning plunger TE01 TE02 TE01 Fig 1 Schematic drawing

8/24/2015Pengda Gu, Structure Meeting 3. Design of the components of 30GHz pulse stretcher for CTF2 3.1 Rectangle TE10 to circular TE01 mode converter Composition: Taper from 8.64mm wide to 12.35mm wide + Rectangle TE10 to TE20 mode converter + Taper from 4.32mm high to 12.5mm high + Rectangle TE20 to circular TE01 mode converter

8/24/2015Pengda Gu, Structure Meeting Fig 2 Electric field 5mm Fig 3 dimension Taper from 8.64mm wide to 12.35mm wide

8/24/2015Pengda Gu, Structure Meeting Fig 4 Matrix plot

8/24/2015Pengda Gu, Structure Meeting Rectangle TE10 to TE20 converter Fig5 Electric field mm 17.4mm x y (20,17) (44.04,-7.04) (13.46,28.48) 12.35mm 14.09mm Fig 6 Dimensions of the converter S Matrix at GHz

8/24/2015Pengda Gu, Structure Meeting Fig 7 S12 conversion from TE10 to TE20 and the reflection S11

8/24/2015Pengda Gu, Structure Meeting Taper from 4.32mm high to 12.5mm high No.1 Fig 8 Electric field 21mm Fig 9 Dimension

8/24/2015Pengda Gu, Structure Meeting Fig 10 Matrix plot of S12, S11of TE20 mode

8/24/2015Pengda Gu, Structure Meeting Fig 11 Electric field 5.9mm 8.8mm 11.1mm 21.8mm Taper from 4.32mm high to 12.5mm high No.2

8/24/2015Pengda Gu, Structure Meeting Fig 12 S11 and S12 of TE20 mode

8/24/2015Pengda Gu, Structure Meeting Taper from 4.32mm high to 12.5mm high No.3 Fig 13 Electric field 26mm

8/24/2015Pengda Gu, Structure Meeting Fig 14 S11 and S12 of TE20 mode

8/24/2015Pengda Gu, Structure Meeting Rectangle TE20 to circular TE01 mode converter Fig 15 Electric field S Matrix at GHz 14.5mm 6.27mm 11.03mm 7.3mm 12.5mm mm Profile :

8/24/2015Pengda Gu, Structure Meeting Fig 16 Matrix plot of rectangle TE20 to circular TE01 conversion, S11 of port 1:m1 (dashed), S11 of port1:m1 to port1:m2, S12 of port1:m1 to port2:m1(dotted)

8/24/2015Pengda Gu, Structure Meeting Simulation of the total structure Fig 17 Electric field, using t aper from 4.32mm high to 12.5mm high No mm

8/24/2015Pengda Gu, Structure Meeting Fig 18 Matrix plot of S12, conversion from rectangle TE10 mode to circular TE01mode and S11

8/24/2015Pengda Gu, Structure Meeting 3.3 Circular mode preserving taper Fig 19 TE01 mode transmission Fig 20 Reflection of TE02 mode

8/24/2015Pengda Gu, Structure Meeting Fig 21 S12 for H01 mode as a function of taper length Fig 22 S11 for H01 mode Fig 23 Reflection of H02 mode as a function of taper length

8/24/2015Pengda Gu, Structure Meeting 3.4 Reflective circular TE01 to TE02 converter Fig 24 Field plot of the magnitude of E, excited by mode Fig 25 Field plot of complex magnitude of E, excited by mode

8/24/2015Pengda Gu, Structure Meeting Fig 26 Matrix plot of reflection and TE01 TE02 conversion