Difference: ClicFTMeas (1 vs. 4)

Revision 431 Oct 2014 - JackTowler

Line: 1 to 1
 
META TOPICPARENT name="NewClicBpm"

Feedthrough Simulations

Line: 41 to 41
 
  • Comparing the simulated and measured Q's, the measured value was 444 and the simulated was 343.
  • The separation change that gives a loaded Q of ~500 is about -0.15 mm.
Added:
>
>

Reference Cavity Simulation

  • The above simulations were performed for the reference cavity

Antenna separation change /um Frequency /GHz Loaded Q
-0.30 14.750 276
-0.15 14.742 401
0.0 14.753 575
+0.15 14.740 828
+0.30 14.744 1192

ant_sep_ref.png

 

META FILEATTACHMENT attachment="ant_sep.png" attr="h" comment="" date="1414510524" name="ant_sep.png" path="ant_sep.png" size="33802" user="ztap061" version="1"
Added:
>
>
META FILEATTACHMENT attachment="ant_sep_ref.png" attr="h" comment="" date="1414761803" name="ant_sep_ref.png" path="ant_sep_ref.png" size="32234" user="ztap061" version="1"

Revision 328 Oct 2014 - JackTowler

Line: 1 to 1
 
META TOPICPARENT name="NewClicBpm"

Feedthrough Simulations

Line: 27 to 27
 
  • The effect of the antenna length on the Q was studied in simulation.
Changed:
<
<
Antenna separation change /mm Frequency /GHz Loaded Q
-45 15.005 343
-30 15.011 348
0 15.030 666
+30 15.036 1188
+45 15.031 1710

ant_sep.png

>
>
Antenna separation change /um Frequency /GHz Loaded Q
-0.45 15.005 343
-0.30 15.011 348
-0.15 15.030 504
0.0 15.030 666
+0.30 15.036 1188
+0.45 15.031 1710

ant_sep.png

  • Removing the seals means the antenna separation changes by -0.45 mm, decreasing the overall Q.
  • Comparing the simulated and measured Q's, the measured value was 444 and the simulated was 343.
  • The separation change that gives a loaded Q of ~500 is about -0.15 mm.
 
Changed:
<
<
META FILEATTACHMENT attachment="ant_sep.png" attr="h" comment="" date="1414503789" name="ant_sep.png" path="ant_sep.png" size="33222" user="ztap061" version="1"
>
>
META FILEATTACHMENT attachment="ant_sep.png" attr="h" comment="" date="1414510524" name="ant_sep.png" path="ant_sep.png" size="33802" user="ztap061" version="1"

Revision 228 Oct 2014 - JackTowler

Line: 1 to 1
 
META TOPICPARENT name="NewClicBpm"

Feedthrough Simulations

Line: 15 to 15
 
S33 14.996 1200 2222 779 779
S44 14.995 1394 2221 857 857
Changed:
<
<
  • Effect of removing seals
>
>
  • Effect of removing seals, i.e. the antennae protrude 0.45 mm further into the waveguides.
 
Frequency /GHz Unloaded Q External Q Loaded Q Loaded Q check
14.999 444 714 280 274
Added:
>
>
  • The external Q has reduced to a value closer to the expected number.
  • However, the loaded Q is too small, caused by a low internal Q.

Position Cavity Simulation

  • The effect of the antenna length on the Q was studied in simulation.

Antenna separation change /mm Frequency /GHz Loaded Q
-45 15.005 343
-30 15.011 348
0 15.030 666
+30 15.036 1188
+45 15.031 1710

ant_sep.png

 
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Added:
>
>
META FILEATTACHMENT attachment="ant_sep.png" attr="h" comment="" date="1414503789" name="ant_sep.png" path="ant_sep.png" size="33222" user="ztap061" version="1"

Revision 122 Oct 2014 - JackTowler

Line: 1 to 1
Added:
>
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META TOPICPARENT name="NewClicBpm"

Feedthrough Simulations

  • The results of the RF measurements showed that the external Q of the BPM was much higher than anticipated.
  • A study was done to reduce the Q factor and return the Q to its goal value of 500.

Position Cavity RF Measurement

  • Results from RF measurement

S Parameter Frequency /GHz Unloaded Q External Q Loaded Q Loaded Q check
S11 14.996 1154 2450 789 789
S22 14.995 1250 2999 869 882
S33 14.996 1200 2222 779 779
S44 14.995 1394 2221 857 857

  • Effect of removing seals

Frequency /GHz Unloaded Q External Q Loaded Q Loaded Q check
14.999 444 714 280 274

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Settings just to customise this page

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