Antenna Layout with battery

[Leonardo]

Hello All,

I'm thinking a small plastic case for a portable device.

It is possible to place pcb board (with pcb antenna) above the battery (Li-Po) or can interfere with RF?

I've very little space with case..

Thank you Leonardo

[Asbjørn]

It's a challenge with very small boards to get enough space/room for antenna and ground plane. In general you should try to keep the antenna outside the battery, so that the antenna is in as close to open air as possible. For small boards this can be difficult and it is possible to place the PCB with antenna on top of the battery, but it is very important that you keep in mind that this will reduce the antenna performance in the direction towards the battery and at worst, also the performance overall. So it's not the ideal scenario. It becomes important to tune the antenna in the application to at least tune out any impedance mismatch due to battery/antenna placement.

You could have a look at what we have done for the nRF51822 beacon kit. Although this is not ideal, it at least give you an idea of how we approached the same issue. The kit works ok, but the performance is far less than what we see out of for example the nRF51-DK.