I've been designing a prototipe with an ATmega128RFA1 chip and in the latest wireless communication tests I've done I'm able to separate two nodes between 4 to 8 meters before starting losing communication and/or getting CRC errors.
I've been checking the LQI which stays almost always at max value (doesn't drop below 0xFB even when losing packets) and the ED level (which is around 0x10 when at a couple of meters away, that's a low value isn't it?).
Right now I'm using a ceramic antenna, but if necessary, I'm willing to change it and use an U.FL or RP-SMA connector and an external antenna. Would that give me a better range?
The µC is working in basic mode.
I'm attaching an image of the RF part of two prototipes.
I realized there's too little ground on both boards, and the distance between the balun and the µC is too long, would that shorten the possible range on my boards?
I also made a couple of tests with the ATmega128RFA1 evaluation kits, getting similar range (which is too close)