Hi,
After examining datasheet for DWM3000 i came up with doubt.
If we place module completely inside of pcb, do we need ground plane after 10 mm away from lateral sides?
Like that
And i examined eval board and its size more than DWM3000 + 10mm(right side + 10mm(left side), so what is deal specifying 10mm for second option that mentioned in datasheet.
thanks…
You don’t need a ground plane. The keep out given is the minimum size needed for reasonable performance, it’s not an exact requirement that must be met exactly.
The more empty space you can get around the antenna the better.
@AndyA So why datasheet mention it like that “In Figure 10 below, ‘d’ should ideally be 10 mm.
This gives the most vertically polarized radiation pattern. As ‘d’ is increased from 10 mm the degree of vertical polarization reduces.”. Why they didn’t say “minimum” instead of it should be 10 mm? Also they mentioned increasing this value will cause to decreasing in vertical component.
All of the examples shown assume d is defining the total width of the pcb.
They are saying that larger values of d will give less vertical polarization but presumably more horizontal, which may be good or may be bad depending on how the systems are going to be mounts relative to each other.
I’m no RF expert but I suspect that if you extended the ground plane either side of the antenna as you showed you would end up with a far more directional antenna pattern, you would increase gain in some directions and reduce it in others. Again, this could be a good thing depending on your exact situation, normally the aim is to have a system where the gain is as uniform as practical but if you can control the relative orientations a more directional antenna can be a good thing.
