RE: PCB Antenna. Tuning not necesary

Mario — Tue, 03 Feb 2015 12:09:51 GMT

I thik I'm going to remove the pi-network. Even if it gives the chance to tune the antenna, I actually can't do it without lab equipment. Maybe by measuring RSSI? Sounds messy. As you suggest, it should work more or less fine. I don't need low range communication (with a couple of meters it's okay). Thank you!

RE: PCB Antenna. Tuning not necesary

Asbjørn — Tue, 03 Feb 2015 10:11:15 GMT

Yes, you can connect the output of the balun to the input of the antenna. You have added pi-network, but unless you are doing measurements on the antenna, just use a 0 Ohm in R3. You might have a little bit more loss than in an optimized situation, but you should still see some good range even with an antenna that haven't been optimized.

As you suspect, the antenna characteristics will change slightly based on size and shape of ground plane, distance to other metal parts, housing, where it's worn/used and so on. So the antenna might be tuned for a good 50 Ohm characteristics on the TI test board, but for all other application it will be slightly different. But the difference is usually not noticeable in a normal range/use case.