Fero wrote:
Hi Tom,

I have got one more question : could this RF-4 material be used for
frequency up to 2,4 GHz too ? ( blue toot )
Namely, Nordic offers chips for this frequency, too.

Thanks a lot.

Fero

I used ordinary FR-4 for a 6 GHz pulsed oscillator in a commercial
product, and the last I heard it was working fine in mass production.
But it's used only in a dry environment, and doesn't have any high Q
networks or filters. If your design can tolerate relatively high loss
and a moderate dielectric constant (about 5) that varies with
temperature and humidity, FR-4 is fine. If it can't, you should consider
Rogers PTFE board products or something similar.

Roy Lewallen, W7EL