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Thermal Gaps:

Two options for thermal gaps are the annular choke and the photonic crystal joint (PCJ). The EVLA annular choke and a PCJ were modeled with the K band Feed. The EVLA choke has the slightly better return loss and also a smaller profile. This is a proven design and most likely the thermal gap design for the FPA. The PCJ is more impervious to offsets than the choke, however.

EVLA choke with K band Feed
PCJ with K band Feed

A lateral misalignment of 0.053" for each of the thermal gaps:

EVLA choke S11 with misalignment
EVLA choke S21 with misalignment
PCJ S11 with misalignment
PCJ S21 with misalignment

PCJ

A CST model of S11 for a K band annular choke with circular waveguide diameter 0.543" : PCJs11.bmp
A CST model of S21 for a K band annular choke with circular waveguide diameter 0.543" : PCJs21.bmp

K-Band Annular Choke

A CST model of S11 for the EVLA K band with circular waveguide diameter 0.543" : S11EVLA.bmp
A CST model of S21 for the EVLA K band with circular waveguide diameter 0.543" : S21EVLA.bmp

Topic attachments
I Attachment Action Size Date WhoSorted ascending Comment
GapProbeTP3wg.bmpbmp GapProbeTP3wg.bmp manage 1 MB 2007-11-05 - 11:04 StevenWhite  
Kdewartop.dwgdwg Kdewartop.dwg manage 180 K 2007-10-04 - 07:57 StevenWhite  
NRAO_PCJ.pdfpdf NRAO_PCJ.pdf manage 537 K 2007-10-03 - 10:37 StevenWhite  
PCJs11.bmpbmp PCJs11.bmp manage 2 MB 2007-10-29 - 09:03 StevenWhite  
PCJs21.bmpbmp PCJs21.bmp manage 2 MB 2007-10-29 - 09:04 StevenWhite  
Port2.bmpbmp Port2.bmp manage 1 MB 2007-11-05 - 11:07 StevenWhite  
S11EVLA.bmpbmp S11EVLA.bmp manage 1 MB 2007-11-19 - 11:57 StevenWhite  
S11EVLAoffset10l.bmpbmp S11EVLAoffset10l.bmp manage 1 MB 2007-11-19 - 11:58 StevenWhite  
S11PCJ10l.bmpbmp S11PCJ10l.bmp manage 1 MB 2007-11-19 - 12:42 StevenWhite  
S11gap10.bmpbmp S11gap10.bmp manage 1 MB 2007-11-05 - 09:31 StevenWhite  
S11stepw1.bmpbmp S11stepw1.bmp manage 1 MB 2007-11-01 - 13:44 StevenWhite  
S21EVLA.bmpbmp S21EVLA.bmp manage 1 MB 2007-11-19 - 11:57 StevenWhite  
S21EVLAoffset10l.bmpbmp S21EVLAoffset10l.bmp manage 1 MB 2007-11-19 - 11:58 StevenWhite  
S21PCJ10l.bmpbmp S21PCJ10l.bmp manage 1 MB 2007-11-19 - 12:43 StevenWhite  
S21gap10.bmpbmp S21gap10.bmp manage 1 MB 2007-11-05 - 09:32 StevenWhite  
S21stepw1.bmpbmp S21stepw1.bmp manage 1 MB 2007-11-01 - 13:44 StevenWhite  
TTstandoff.dwgdwg TTstandoff.dwg manage 82 K 2007-10-04 - 07:57 StevenWhite  
TTtop.dwgdwg TTtop.dwg manage 106 K 2007-10-04 - 07:56 StevenWhite  
TTtube.dwgdwg TTtube.dwg manage 90 K 2007-10-04 - 07:56 StevenWhite  
UVA_PCJ.pdfpdf UVA_PCJ.pdf manage 832 K 2007-10-03 - 10:37 StevenWhite  
chokecomponent.bmpbmp chokecomponent.bmp manage 2 MB 2007-10-29 - 09:19 StevenWhite  
component.bmpbmp component.bmp manage 1 MB 2007-11-01 - 13:51 StevenWhite  
feedwevla.bmpbmp feedwevla.bmp manage 1 MB 2007-11-19 - 10:48 StevenWhite  
feedwpcj.bmpbmp feedwpcj.bmp manage 1 MB 2007-11-19 - 10:48 StevenWhite  
s11gap10.bmpbmp s11gap10.bmp manage 2 MB 2007-11-05 - 09:29 StevenWhite  
s11optTP3wg.bmpbmp s11optTP3wg.bmp manage 1 MB 2007-11-05 - 10:50 StevenWhite  
s21gap10.bmpbmp s21gap10.bmp manage 2 MB 2007-11-05 - 09:29 StevenWhite  
s21optTP3wg.bmpbmp s21optTP3wg.bmp manage 1 MB 2007-11-05 - 10:51 StevenWhite  
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Topic revision: r49 - 2008-02-22, StevenWhite
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