Stacking of antenna on top of ST25R3916B board

[dave100]

Hi,

I'm designing a NFC reader using ST25R3916B. Due to space and distance constraints, I'm considering stacking the PCB antenna 20mm above the ST25R3916B board. The required tag reading direction is on top of the antenna. The connection between the 2 boards will be 2 copper pins soldered on both boards. Please kindly see the illustration below.

I wonder if this is workable and would appreciate it if I could get some advice or recommendations on the impedance matching, parasitic capacitance / inductance and EMI considerations.

Thank you and best regards,

Dave

[Travis Palmer · Accepted solution]

Hello Dave,

I see no issue with your approach. 

The only critical point i see, the EMC filter (most critical) and the other components of the matching network should be as close as possible - on the same PCB - as the ST25R3916B.

When measuring the antenna parameters also the 20mm connection traces / pin header should be considered.

If possible the connection traces could be twisted.

br Travis

[dave100]

Hello Travis,

Thank you for your reply.

I'll take note of the EMC filter and matching network design.

Best regards,

Dave