topic Re: NFC over Pins in NFC

NFC over Pins

jof — Thu, 07 Mar 2019 08:58:38 GMT

Because of restricted space, it would be either possible to create a pcb containing a NFC PCB Antena + Reader frontend and connect to the master board with a pin header (2,45mm -6pin SPI). This soultion would provide very short connection from the NFC-Chip with matching network to the Antenna (only around 1mm). But because of restrcted space, the antenna would be shrinked by the NFC Chip + Parts

There would be the possibility to use the full pcb space for the antenna, and connect the antenna via a 2.54mm 2-pin Header to another PCB. The size of the Antenna would be nearly doubled then.

But i've read that nfc circuits are problematic in case of inpedance matching between antenna network and antenna.

Is it possible use to connect the antenna via the pins or would it be a big risk / problematic in series production.?

Re: NFC over Pins

weidong_sun — Fri, 08 Mar 2019 06:20:49 GMT

Hello Jonathan,

It 's hard to say if there exists a big risk. but I think it is better for you to choose a professional RF antenna. like below:

if you think it better, you can get materials on the link:

https://www.i-pex.com/Products/Micro-RF-Coax-Connector

[comment] if PCB space is restricted, you can consider using single ended antenna.

If you want solution for single ended antenna or informations on part number. you can create a new case for them on our salesforce system, I will send it to you by our System.

Have a nice day!

NXP TIC Weidong Sun

Re: NFC over Pins

jof — Fri, 08 Mar 2019 06:58:20 GMT

i've attached the current board witht he smaller antenna, you can see the RFID Card in the back (white card). If the reader could be moved from the board, the new antenna could be way bigger as seen below. The 8 Pin Connector would be replaced by ufl type, or it would be possible to even use sticky antenna with ufl cable on them

Re: NFC over Pins

weidong_sun — Mon, 11 Mar 2019 00:24:49 GMT

Hello Jonathan Frech,

See blelow , please!

>>Is it possible use to connect the antenna via the pins or would it be a big risk / problematic in series production.?

Although we don't have the same usage as yours, I think antenna connection via pins should be feasible. The following is the CLRC663 Bule DEMO board, see 2 pins in red circle, which is very similar to your application. So I feel your antenna connection should be OK.

Have a nice day!

NXP TIC Weidong Sun

Re: NFC over Pins

jof — Thu, 28 Mar 2019 10:58:26 GMT

Yes, but in our case the antenna would be not on the same pcb like on the board shown.

The antenna would be plugged in in 2.54 pitch headers Like this

https://cdn.shopify.com/s/files/1/1034/1611/products/2469336-40.jpg?v=1501596728

But only the antenna would be on the right pcb.

Since i've seen a few rfid designs that used twisted pair cable for antenna connection, i think it should be possible to use headers, or isn't it?

Re: NFC over Pins

weidong_sun — Fri, 29 Mar 2019 03:01:42 GMT

Yes, right. in recent days, I have met some RFID users also use this kind of connection, and no problem.

so I think you can use it.

Have a nice day!

BR,

Weidong