antenna circuit capacitor tolerances

RE: antenna circuit capacitor tolerances

Asbjørn — Mon, 30 Mar 2015 13:59:52 GMT

I would agree with @Locky here. If you want to change component manufacturer and tolerances, make sure that this would still be ok with regard to performance of your boards. Usually it won't be a problem, but as Locky states, testing is important here. If you are fine with potentially larger variations in a batch, but still with all of them within acceptable performance, there's nothing wrong in switching supplier. The risk is that output power, sensitivity, attenuation of harmonics could vary more across your boards along with the higher tolerances that you introduce with the new components.

I don't have any specific component recommendation, but I would recommend you to test with the new components before you go into production.

RE: antenna circuit capacitor tolerances

FredNovalia — Thu, 26 Mar 2015 10:19:47 GMT

Thanks for the advice. We will go into full production (>10000) but hopefully we will get a test batch from the manufacturer.

RE: antenna circuit capacitor tolerances

Locky — Wed, 25 Mar 2015 18:21:11 GMT

These are fairly standard tolerances for precision RF tuning components. It is likely you PCB specs will have a much larger variation than these values i.e. the impedance of your RF trace. The main questions you have to ask yourself are:

What volume are you producing? More volume = More potential for full spectrum variation
What RF performance variations are you currently seeing across a production batch?
What is acceptable RF performance variation to you / your customers?

Likely you won't see much difference in a 0.25pF VS 0.1pF tolerance. But RF is black magic until you actually test ;)