Hello,
I try design PCB Antenna for the PN5180 but i have not a lot of experiences with RF circuits. I watched and read tutorials how to design NFC Antenna. I don't know if the antenna is properly designed for the PN5180.
I used NXP NFC Antenna Tool to design circuit. The app gave me a below results:
After That I assembled circuit and measure. My antenna has 3-turns. I used NanoVNA V2 for measured antena coil. Results:
La = ~1.48uH @13.56MHz,
Ra = ~2.5R @13.56MHz,
Ca = ~1 - 2pF (?)
I used RFSim99 tool for tuned antenna. After tuned the curcuit looks like this:
The NanoVNA shows:
Return Loss: -15.66dB
SWR: 1.45
Reflection power: ~2.7%
Z = 36.4R @13.56MHz
Is the antenna matching result good for PN5180?
Hi Draxter, you should use NXP-NFC-Reader Antenna Tuning.xls.
Must achieve measurement for PN5180
Z = 20R @13.56MHz for best transfer.
1- Measure your antenna with NanoVNA without circuit only antenna (Be careful with the calibration with the wire to measure), and obtain the R and L parameters (C not yet)
2-In these values in the NXP-NFC-Reader Antenna Tuning.xls (Attention in this) must reach the value indicated in the "C0 Calculated" field is very important.
3- Assemble your circuit and measure with the NanoVNA, then adjust the R L C values of the antenna in the simulation until you get a shape and values similar to those you read in reality.
4- You must in these values obtained from this "antenna" in the file NXP-NFC-Reader Antenna Tuning.xls and recalculate.
5- At this point you should have the final values to match at Z = 20 ohm 13.56Mhz
If step 5 didn't work for you, there may be something wrong, like a bad calibration or some value in the file that wasn't loaded correctly.
You should get this graph in the simulation and in reality
Example in my case
Note: Unconnect the soldering iron for add a change in your board if you have the nanovna connected.
Hope it help you. Have a nice day.
