21540 PA hardware test

RE: 21540 PA hardware test

Hieu — Mon, 15 Sep 2025 09:33:15 GMT

Hi William,

[quote user="William.wei"]so, if customer need to test PA performance, the only thing customer need to do is testing DTM right?[/quote]

It depends on what the customer wants to verify. RF testing is quite a bit outside of my expertise, but to my understanding, you want to have a proper radio test with a spectrum analyzer.

[quote user="William.wei"]another question is, how to test the sensitivity, do we have any docs on this?[/quote]

We have a white paper on that here: RF Performance Test Guidelines.

Regards,

Hieu

RE: 21540 PA hardware test

William.wei — Mon, 15 Sep 2025 02:31:34 GMT

hi Hieu,

Thank you for you reply.

so, if customer need to test PA performance, the only thing customer need to do is testing DTM right?

another question is, how to test the sensitivity, do we have any docs on this?

Regards,

William.

RE: 21540 PA hardware test

Hieu — Fri, 12 Sep 2025 17:21:13 GMT

Hi William,

The change in DTM app is to address another compatibility issue between the app and the DTM sample.

It seems the TX Power limit is something that was overlooked. I have reported to the app development team but cannot comment on when that will be fixed. If you need it urgently, you need to contact our sales representative.

As a work around, you can build the DTM sample with CONFIG_DTM_POWER_CONTROL_AUTOMATIC. This will disable automatic FEM gain control from the nRF Connect for Desktop app. You can then manually change the FEM gain using the serial terminal using the vendor command FEM_TX_POWER_CONTROL_SET. You can refer to the sample's README for more information about this command.

Our apologies for the inconveniences.

Regards,

Hieu

RE: 21540 PA hardware test

William.wei — Thu, 11 Sep 2025 02:32:22 GMT

hi Hieu，

i can suggest customer to use ncs3.1.0. however, for DTM app i couldnot see what is improved when testing FEM. it only support 8 db for version2.5.3.

Regards,

William.

RE: 21540 PA hardware test

Hieu — Wed, 10 Sep 2025 08:13:55 GMT

Hi Willliam,

There was an issue with both the DTM sample and DTM app that affects the nRF54L15 and FEM setup. They are fixed in the latest version of NCS and the DTM app.

What version is the customer testing on? Can you check if they still see the same result with NCS v3.1.0 and DTM app v2.5.3 or newer?

Regards,

Hieu

RE: 21540 PA hardware test

Hieu — Mon, 08 Sep 2025 18:55:49 GMT

Hello William,

I will look into this and follow-up in 1-2 work days.

Regards,

Hieu