Minimum PCB size and reasonable antenna efficiency

[hcglitte]

Hi,

The datasheet for the antenna used in the dev kit, P822601, has its specification performance measured on a PCB DUT at 140 x 50 mm^2 - which seems rather unnecessary big, even for the lowest 700 MHz band. A smaller PCB (half size) should still produce adequate antenna performance, in my opinion, based on some similar antenna simulations.

I was wondering if nordic has done any testing with this antenna (or others) on smaller sized PCB's and measured the antenna efficiency.

Thanks 

[Marjeris Romero]

Hi,

We encourage you to consult the antenna manufacturer regarding the minimum sizing of the ground plane and other performance data. A typical rule of thumb is to keep the ground plane larger than a 1/4 wavelength.

It is also possible to have a smaller ground plane but the antenna performance would gradually decrease as you decrease the ground plane. Different antenna parts will also have different performances at the same size of the ground plane, so that's why you should discuss this closely with the antenna manufacturer if you are not following the numbers given in the datasheet.

Changing the ground plane will also mean you need to change the matching components of the antenna specified in the datasheet (specially if the ground plane is smaller than a 1/4 wavelength).

Best Regards,

Marjeris