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 

[cbd]

I always thought that you looked for a ground plane that was related to the wavelength that you're trying to transmit, with full wavelength being the most efficient.

I guess that when supplying a datasheet a supplier will tend to give you the best case scenario.

[hcglitte]

I normally get good results when the ground plane is about 1/4 wavelength and the antenna is a meandering monopole. This is a good starting point for simulations (at least this is what I do). But I would love to see some real world examples where the PCB has been minimized to the minimum possible, still with OK performance. I wonder if nordic has done any such studies, would love to see some data.