13.56 MHz RFID Switches
I have an array of 16 antennas (coils) that I would like to multiplex using some kind of analog switches or multiplexers. I'm using the Seeedstudio NFC RFID module and it works fine with one antenna connected to it.
I have tried using the LCA110 MOSFET optocouplers, but it works okay only for a few antennas (3 or 4). Somehow, when I add more antennas it stops working, and I don't know why . Any help would be greatly appreciated.
Thank you,
Robert
Hard to guess without seeing your actual circuit.
The fact that you are using a high voltage analog switch suggests that you are multiplexing the RFID coil behind the matching network. But the switch has considerable capacitance, this can't work without tuning/redesigning the matching network.
A more promising approach might be to use individual matching networks for each coil and perform the multiplexing with low resistance, low voltage switches at the reader IC interface.
FVM,
Thank you for your help. We have a four by four antenna array with 16 coils in it. Our goal is to use 4 switches on two sides for a total 8 switches to control the 16 coils. We want to use the matching network that comes in the Seeedstudio NFC RFID module. I think that 8 relays will work for this purpose but we want to use some solid state kind of switch. Any suggestions? Do you think that the MASW-007813 will work? Any other suggestions?
We are controlling the switches with a microcontroller.
Thank you,
Robert