MPSL with two chained FEMs on nRF5340

RE: MPSL with two chained FEMs on nRF5340

PaKa — Fri, 10 May 2024 07:21:39 GMT

You may do all those things on the transmitter side.

On the receiver side you have to select either ESB or AoA, you will not be able to run both at the same time.

This as AoA reception is only supported by the Zephyr controller in nRF Connect SDK 2.2 and this doesn't support running ESB.

If you want ESB then you need to use the SoftDevice Controller Subsystem and this does not support AoA receiver funtionality.

RE: MPSL with two chained FEMs on nRF5340

jbreal — Wed, 08 May 2024 21:55:38 GMT

The application would be using Bluetooth and ESB via the use of the MPSL library in the nRF SDK 2.6.1. And yes, the intent would be to use AoA as well.

RE: MPSL with two chained FEMs on nRF5340

PaKa — Wed, 08 May 2024 07:54:20 GMT

Is this for an AoA receiver? That is NOT supported with the SoftDevice Controller Subsystem which is the only option that uses MPSL so if this is the case, then the answer is "Not Applicable".

For AoA receiver you need to look at the nRF Connect SDK 2.2 and using the Zephyr controller. If this is to get LNA functionality then I would check that the LNA will work with the waveforms coming out when you switch the antennas.

RE: MPSL with two chained FEMs on nRF5340

jbreal — Tue, 07 May 2024 20:33:09 GMT

We are using a uBlox NORA-B12 module, which has a SkyWorks SKY66405 builtin, and then we are also planning on using AoA, so we have an RF mux, and then an FEM (also SKY66405 ) at the end of each of those.

.                   Ant   +----SKY66405--RF1
.                  Demux  +     |
.  ____________     _     |  +--+
. |            |RF / |----+  |
. |   SKY66405-|---  |-------|-SKY66405--RF2
. |         |  |   \_|----+  |  |
. | nRF5340-+  |    |     |  +--+
. |____|_______|    |     |  |
.   |  | ANTSEL     |     +--|-SKY66405--RFn
.   |  +------------+        |  |
.   |                        |  |
.   +------------------------+--+
.                    CRX/CTX/CPS

RE: MPSL with two chained FEMs on nRF5340

JONATHAN LL — Tue, 07 May 2024 13:59:26 GMT

Can you share a diagram of how this is connected to each other? I am struggling a bit to see how it is connected to one another.

And are you using the nRF21540 as a FEM or something else?

Regards,
Jonathan