
Hi there,
I bought a NanoVNA in the hope to upgrade a RFID board I have. It has a RF module with horrible AT commands. I would like to integrate to the PCB a simpler chip from ST.
I have a custom antenna on this that is purpose made. I have no datasheet for it, it has been matched with the module.
I thought simply measuring the impedance of the bare antenna + output of the chip would allow me to design a matching circuit for the 2 that would work.
First thing, the antenna seems oddly tuned. It reasonnate at 12.85MHz when RFID should be 13.56Mhz. Is the matching circuit able to shift the resonance freq ?
Would you know of any good tutorial to do impedance matching ?
Best Regards,
Vincent