Nordic Thingy:91 Antennas

[JordanK]

We're working on a board design that is based off the Thingy:91 design, and I noticed that the Thingy:91 uses a separate small antenna for Bluetooth.

The main antenna on the board, an Ignion TRIO NN03-310, supports LTE, GNSS, and Bluetooth, but it looks like it's only actually being used for LTE and GNSS, while Bluetooth is using the separate antenna. Is there a reason that it uses a separate antenna for Bluetooth, instead of using the Ignion TRIO's Bluetooth capabilities?

Just trying to determine if we can use the Ignion TRIO for all three on our board, or if we need a separate Bluetooth antenna as well.

Also, could you clarify if the Thingy:91 includes an NFC antenna? It's unclear, because the documentation mentions "NFC port and antenna", but I don't actually see an NFC antenna in images/schematics of the device. If an NFC antenna must be included separately, what components does it need in terms of a matching circuit?

Thanks!

[Simonr]

Hi

As you can see in the Thingy:91 user guide, the second "BLE only" antenna, is connected to the onboard nRF52840, and not the nRF9160, which is why these two antennas are separate on the Thingy:91. The choice of the TRIO both supporting LTE and BLE is just a coincidence. Since it's only connected to the nRF9160 it will only be used for cellular communication. The reason there are two separate ones is so we can have cellular and BLE communications ongoing simultaneously.

As for the NFC antenna, this doesn't look like an ordinary antenna but like the picture below, and is supposed to go into the connector J5 in the Thingy:91 to have the passive NFC tag functionality.

Best regards,

Simon