I'm trying to make my own customized version of the Arduino Nano 33 IoT. I noticed in the Arduino circuit schematic, there is an antenna specified, and it connects to the Bluetooth unit as if it's an external component. However, when I look up the Bluetooth device used (NINA W102), the antenna is already included in the NINA module. In fact, when I'm looking at the NinaW102, I can see the antenna already attached to the top of it.

My question is, am I correct in assuming that I DO NOT need to specify the antenna in my schematic, since the Nina module already includes one? This is my first PCB design I'm sending to a manufacturer and I want to make sure to get it right. Thank you!

enter image description here

Arduino Nano schematic PDF

Arduino Nano spec page

Nina W102 Datasheet


1 Answer 1


As per section 1.5.2: in the NINA W102 data sheet:

“The NINA-W102 modules use an integrated antenna mounted on the PCB. The PCB outline is 10.0 x 14.0 mm. The RF signal pin is not connected to any signal path.”

Further down in the pin table it is noted than pin 13 is only used on 101 modules without the internal antenna. Therefore you should not connect an external antenna.

  • 1
    \$\begingroup\$ That is, you CAN'T use an external antenna if you specify the chip with the internal antenna. \$\endgroup\$
    – david
    Commented Apr 21, 2020 at 9:42
  • \$\begingroup\$ Thanks @david; I've updated my answer to make this more clear. \$\endgroup\$ Commented Apr 21, 2020 at 11:57
  • \$\begingroup\$ Thank you that's what I thought @david and Jakob. So is there a reason why Arduino put the antenna in their schematic? (See my screenshot in the original post) \$\endgroup\$ Commented Apr 21, 2020 at 14:55
  • \$\begingroup\$ I really don’t know as I can’t even see the antenna connector anywhere on the photos of the board itself, but you could download the Eagle files and look for it. \$\endgroup\$ Commented Apr 21, 2020 at 15:26
  • 1
    \$\begingroup\$ It would be reasonable to include an antenna on a schematic: a schematic is a view of an idea. But that schematic is misleading: either the part number is wrong, or the labeling is misleading, because we know that for W102 pin 13 is not connected. The connection should not be labeled '13', or should be unambiguously labeled in some other way. \$\endgroup\$
    – david
    Commented Apr 23, 2020 at 3:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.