help: antenna inside a box
 

A RF module was integrated with an application. The whole system
including the RF module, antenna and application components must be put
inside a plastic box (per the users' requirement). Unfortunately, the
application components include a transformer and some other metal
components, and the box (designed beyond my control) is small, and the
antenna is very close to these metal comonents inside the plastic box
(very little room inside the box). I found the RF performance (e.g.
Tx/Rx distance) is much weaker than if the antenna is farther separated
from the the other components (for example, let the antenna stick out
of the box...). Could you make some suggestions or guidelines to deal
with this situation so that the RF performance is as good as if the
antenna is stick out of the box ....

Thanks for your help.

Jin

help: antenna inside a box
 

wrote:

A RF module was integrated with an application. The whole system
including the RF module, antenna and application components must be put
inside a plastic box (per the users' requirement). Unfortunately, the
application components include a transformer and some other metal
components, and the box (designed beyond my control) is small, and the
antenna is very close to these metal comonents inside the plastic box
(very little room inside the box). I found the RF performance (e.g.
Tx/Rx distance) is much weaker than if the antenna is farther separated
from the the other components (for example, let the antenna stick out
of the box...). Could you make some suggestions or guidelines to deal
with this situation so that the RF performance is as good as if the
antenna is stick out of the box ....

Thanks for your help.

Jin

If you were to make the antenna a ground plane or vertical and use a piece of
copper clad circuit board as the plane, it might provide a good degree of
isolation from the other components below that plane.

Irv
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

help: antenna inside a box
 

Thanks, Irv,

Could you elaberate a liitle bit "make the antenna a ground plane or
vertical and use a piece of copper clad circuit board as the plane" ?
Do you mean to have a piece of copper clad board separete (or inserted
between) the antenna and the other component? Or make the antenna
out of ..... ?
I will read your home pages as well.

Thanks.
Jin

help: antenna inside a box
 

wrote:

Thanks, Irv,

Could you elaberate a liitle bit "make the antenna a ground plane or
vertical and use a piece of copper clad circuit board as the plane" ?
Do you mean to have a piece of copper clad board separete (or inserted
between) the antenna and the other component? Or make the antenna
out of ..... ?
I will read your home pages as well.

Thanks.
Jin

What I suggested is to use the copper separation between the antenna and
the other components where it can act as a shield, and to integrate the copper
as part of the antenna -- i.e. it becomes the ground plane for a vertical element which
is your radiator.

Irv VE6BP
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

help: antenna inside a box
 

In article , Irv Finkleman wrote:

If you were to make the antenna a ground plane or vertical and use a piece of
copper clad circuit board as the plane, it might provide a good degree of
isolation from the other components below that plane.

Irv & Jin-

Also consider making a "patch" antenna using the circuit board ground
plane. Of course the size will depend on operating frequency, and it will
probably not be as good as a ground plane antenna.

I don't have any references, but a web search should find information on
patch antennas used on UHF and higher frequencies.

73, Fred, K4DII