OK, I’m rolling my own layout for Nordic’s new nRF24LU1 chip. I am planning on using the chip antenna that Sparkfun has for size reasons. What I don’t know is where can I not have ground plane in relation to this antenna? Should I not have it from the input of the antenna forward or can I have ground plane surrounding the antenna (particularly to the antenna’s left and right)? I know that I shouldn’t have ground plane immediately under the chip antenna on the top side. However, what about having a ground plane on the bottom side under the antenna? If somebody could point me to the rules of ground planes and chip antennas, I would really appreciate it.
No ground plane past the input point for at least 1/4 wavelength!
In the words of Dr. Sparkss
You cannot have it on the left, you cannot have it on the right.
You cannot have it up above, even if board space is too tight.
There should be no ground plane underneath, or anycomponents either.
The range will make you grit your teeth, and sharpen up the cleaver!
So don’t mount it in a metal box, or reactive plastic.
Don’t put it in a rabid fox or conductive wicker basket.
And never ever ever …put the antenna underwater,
The FCC will fine you big and take your first born daughter!(not really)
That’s all I got…
Ron
Haha I like the nursery rhyme. But thanks for your help. I was kind of figuring that there had to be some 1/4 wavelength rule or something like that.
looked at antenna vendors spec sheets or reference designs?
A teeny chip antenna is on the Maxstream XBees I use and there sure a’int 1/4 wavelength of copper underneath.
This vendor says, (at my quick read) that you don’t want a ground plane near a chip antenna. (detunes)