Review of nRF 8001 schematic with Antennae

[Manish Gulia]

I have a schematic in which Balun is connected as a matching network to Ant1&Ant2 pins making the output impedance 50 ohms. Now i want to connect an Antennae to it which is surely of 50ohm but i have read in previous questions on the forum that tuning pi network has to be connected between the output impedance and the antennae(50 ohm). I am attaching my Schematic, review it and can you tell me what will be the values in the pi network i.e the values of L1,C8 and C15. And which antennae should i connect i.e whether PCB Antennae or another. And what will be the specification of the antennae to be connected? Review the schematics and answer the above questions. Any help is appreciated!!.

MySchematic.pdf

[thomas]

Hello, I'm interested in an answer too. RF part on my prototype (nrf51822) doesn't work. I have chosen this ballun and this ceramic antenna with a 50ohm line. I'm not RF engineer, did I forget something?

Attached, my shematic and my layouts

[wlgrd]

Are you sure it will work okay with that balun? I just saw that the sheet says "Optimized for Nordic's Chipset nRF24L01, nRF24L01+, nRF24LE1, nRF24LU1, nRF24AP2, and nRF8001".

[thomas]

RF part on nrf518001 and 51822 are very similar and i've vhosen this ballun because it's bigger than the recomanded BAL-NRF02D3 but yes, maybe it was an error...

[wlgrd]

I personally don't know at all, just wanted to make sure you had considered it :)

[Ole Morten]

This is really not a related question at all, and would hence be better off as a separate question (or a support case).

However, as wilhelmsen says, when choosing a balun, it's important to pick one that's specifically been measured and verified with the chip in question, and using the balun you've linked to with an nRF51822 is hence not something we'd recommend. Also, as I said in my other reply here, following the reference design is especially important when using a balun, since there isn't any components to tune with.

I'd recommend you to open a support case with your full design as schematics and Gerbers/Altium files, and request a proper review.