This reader operates in the 13.56 MHz ISM band. The reading range is very
close-in, roughly to 1 cm. While the RF link is established by an
"antenna" of sorts, it is not an antenna in the usual sense of the word.
"Antennas" for these RFID applications consist more of a printed planar
inductor in a parallel resonant LC circuit. So design a spiral planar
inductor, model or measure the resulting inductance and choose an
appropriate capacitance to resonate the circuit at 13.56 MHz.
Here is a reference for calculating the inductance of printed spiral planar
inductors:
From there, you can calculate the required lumped capacitance from:
2
LC = 25330 / F
where: L in microhenries
C in picofarads
F in MHz (that's F squared in the above formula)
The combination of these will, then, form a parallel resonant circuit
"antenna".
Dave - W?LEV
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On Tue, Mar 3, 2020 at 1:03 PM <daniel.hussenet@...> wrote:
Hi Everyone,
I'm trying to develop my own rfid antenna for mfrc522. It's my first one,
so... it's very difficult. Do you know the procedure to properly tune my
antenna ? Or a good tutorial to help me use my NanoVNA properly ?
Any help will be very appreciated
Thanks
--
*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*
