Antenna Mounting within case

[HardwareChap]

View attachment FXP611.07.0092C-1219598.pdf

For the antenna attached to this post, does the radiation pattern suggest that it can be mounted either way up in a plastic housing? I'm assuming that the ball like sphere of the pattern fully encases the antenna and isn't just out of the 'top' of it? So, if the antenna was to be shown in say figure 7, it would dissect the radiation pattern along the 'x' arrow showing energy above it, below it and around it?

 

[volker@muehlhaus]

Amendment to my initial post that I deleted:

I was thinking that this antenna is indeed omni-directional, but the 180° patterns shown in the data sheet are not clear about that.
Looking at the claimed 80% efficiency and ~0dBi gain in the pattern plots, I still think that it should be omni-directional, but you better contact the manufacturer to double check.

 

[biff44]

Note that they say it works well ATTACKED to a plastic case. It does not say it will work as well INSIDE OF a plastic case.

These short of things, you buy one, and measure it in your specific application.

 

[Azulykit]

Hi,

As a general rule anything in the immediate vicinity of an antenna will disturb the radiation pattern. The as mounted performance is thus not the "free space" measured value. I find data sheets are often manipulated for marketing purposes, particularly in the commercial world. Let the buyer beware.

You probably also realize that a true omni antenna does not exist. Have you considered polarization variation in your analysis? I also have run into cases where people mount antennas inside metal chassis/enclosures and then are surprised when connectivity is compromised. By the same token, a metal box is often not well shielded. Murphy is alive and well.

Good Luck

 

[biff44]

Hi,

As a general rule anything in the immediate vicinity of an antenna will disturb the radiation pattern.

i am not sure that is the case here. The purchased antenna purports to be independent of mounting surfaces. That would lead me to believe it is something like a patch antenna, with a ground plane on the backside, and it does not matter what you attache the antenna to, since it already has a big enough ground plan internally.

If there is no internal ground plane, i would have a hard time seeing how they can say the filter is independent on what you mount it to!