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antenna enclosure - RF Cafe Forums
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karthik
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Post subject: antenna enclosure
Posted: Fri Oct 27, 2006 11:08 pm
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Joined: Tue Apr 11, 2006
8:13 pm Posts: 34 |
Hi, I had designed an aperture coupled patch
array antenna. I am looking for an easy, quick enclosure
for this antenna so that I could mount it outside,
open to the environment. The antenna is about 60cm
long, 6 cm wide and about a couple of cm deep. Any
suggestions? I dont want to spend too much time
designing an enclosure. I'm essentially looking
for a quick fix solution. Thanks!!
Karthik
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nubbage |
Post subject: Antenna enclosure
Posted: Mon Oct 30, 2006 4:44 am
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General |
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Joined: Fri Feb 17, 2006
12:07 pm Posts: 218 Location: London UK
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My approach has been to locate a scrap plastic seedling
tray from garden center purchases visits, line it
with thin polythene film, place the assembly inside
it and then foam in place either polystyrene packing
foam or polyurethane insulation foam. Remove the
seedling tray and thin polythene film when the curing
process is complete. Both materials are low
loss up to 12GHz, and are fairly imune to UV. Birds
will eventually peck most of it away but you have
probably 5 years of cheap simple weather enclosure
service from this method.
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karthik |
Post subject:
Posted: Mon Oct 30, 2006 9:23 am
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Joined: Tue Apr 11, 2006
8:13 pm Posts: 34 |
Hi Nubbage, Thanks for the suggestion. But
wont polystyrene get damaged in rain/snow? If I've
understood you correct, polystyrene would be exposed
to the environment.
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nubbage |
Post subject:
Posted: Mon Oct 30, 2006 12:22 pm
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General |
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Joined: Fri Feb 17, 2006
12:07 pm Posts: 218 Location: London UK
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Hi Karthik No, if you buy the higher density
foams, they are fairly resistant to ice and snow.
To improve water protection, a thin coat of polyurethane
varnish seals the outer layer of cells. Because
the cell structure is closed, water ingress should
not be a problem. The biggest risk is cracking
due to wind pressure distortion, but the mechanical
strength of the metalic parts should take care that
no stress passes to the plastic foam.
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karthik |
Post subject:
Posted: Mon Oct 30, 2006 9:50 pm
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Joined: Tue Apr 11, 2006
8:13 pm Posts: 34 |
Hi Nubbage, Wind load was another issue I
had in mind. At present, I've just got two PCBs
held in place by spacers. I dont have a metallic
part to provide mechanical stability. I was in two
minds about adding a metallic back plate to the
antennas. I think I should add the back plate. I
was thinking in terms of a molded ABS plastic cover
sort of thing which will enclose the antenna. But
havent been able to find a readymade solution for
this size. I guess your idea would be the quickest
fix. I've never done garden center shopping, but
I did look online for the plastic seedling tray.
I think I need to have it in front of me to really
get a good grasp of your idea!!
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nubbage |
Post subject:
Posted: Tue Oct 31, 2006 4:13 am
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General |
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Joined: Fri Feb 17, 2006
12:07 pm Posts: 218 Location: London UK
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Hi Karthik Three points I would advise on
1) definitely use the backing plate. Aluminum plate
about 0.25 inch thick for mounting the boards on,
and that gives a firm platform for the mast clamp.
2) avoid ABS: the loss at microwave frequencies
can be significant. If you must use it, try the
microwave oven test before you do. It is not necessarily
the ABS, but the plasticisers they use, and these
change with manufacturers so it is difficult to
define exactly. 3) Imagine the seedling tray
as a large pie baking dish, shallow but deep enough
for the boards and backing plate, and with sloping
sides.
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compton |
Post subject: TESSCO
Posted: Thu Feb 15, 2007 8:01 pm
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Joined: Thu Feb 15, 2007
7:29 pm Posts: 1 Location: Reno, NV
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Posted 11/12/2012
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