PN7150 antenna model measurement and sim

[gwctree42]

Hi I'm trying to match my PN7150 system to Taoglas FXC.30.52.0075X.A.dg nfc antenna using the nanovna according to AN12810 but I'm not sure I'm getting the first step correct of measuring the antenna by itself. 

I cal'd the nanovna and connected it directly to the antenna with no matching circuit and got the result that I attached, which resembles AN12810.fig18 as expected. 

But building the rfsim99 model I used the values given in the antenna ds but I'm not seeing how to get the sim model to match the measurement as a starting point.

Could I get some suggestions on how to improve the model ? 

[Tomas_Parizek · Accepted solution]

Hello gwctree42, 

In case you would like to have the antenna model as precise as possible. You can try to use the s-box model as shown below: 

You should be able to save the measured VNA results in s1p format and then import them to RFSIM99. 

BR

Tomas 

[gwctree42]

Hi Tomas thanks that's helpful ! 

Fyi to anyone else following along it looks like rfsim99 only imports the first 2000 points of the s1p so you need to crop or decimate the file accordingly.

[EduardoZamora]

Hello @gwctree42

Hope you are doing well.

Please, consider that PN7150 is Not Recommended for New Designs. We recommend using PN7160 instead.

You will need to calculate the components of the EMC filter and matching network according to the values you measured from the antenna.

Please, take a look at the PN7150 Antenna Design and Matching Guide. Chapter 3 describes the procedure for antenna matching. Also, the NFC Antenna Tool could be very helpful for you.

Additionally, please refer to the NFC Antenna Design training, an online training series that could help you with key aspects for the antenna, optimizing and debugging, and testing to get the best-matched antenna for the product.

Regards,
Eduardo.

[gwctree42]

Thanks I forgot to mention that as part of this project I'm looking at updating the design from PN7150 to PN7160. No questions on that front. 

But did you read my question and have any insight to offer about improving my antenna model ?