The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

RE: The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

JONATHAN LL — Wed, 22 Apr 2026 09:31:13 GMT

Hi, on the DK we have a connector in the RF path that can be used to connect an external antenna with the right adapters.

J1 on the DK's can be used for this.

Regards,
Jonathan

RE: The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

731571731 — Tue, 21 Apr 2026 19:30:23 GMT

Hello, I'm very interested in the external antenna you mentioned. When performing one-to-many ranging using channel sounding, antenna issues often prevent data collection from some devices, leading to positioning failures. I'd like to install an external antenna to solve this problem. Could you please tell me the specific location of the RF path? Does it require soldering?

RE: The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

JONATHAN LL — Thu, 22 May 2025 13:55:50 GMT

There are multiple factors that effect the result here when doing distance measurements.

The relative antenna orientation will effect how the phase of the signal is perceived by the receiving antenna regales of the directional gain.

But the antenna gain is also a major factor. On our DK's with the onboard antenna the gain is approximately 0dBi.

[quote user="youren"]Also, when measuring this radiation pattern, is the receiver positioned at the 0-degree direction?[/quote]

I am not sure, but these measurements where done many years ago and there is not much info left on the process. I presume that the board was spinning while the receiver was stationary when these measurements where done. to map out the radiation patter, but I am not sure exactly how this was done.

Regards,
Jonathan

RE: The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

AllenDev — Thu, 22 May 2025 02:25:44 GMT

I later discovered some issues with the antenna radiation pattern.

The area with the highest energy is at -20dBm, does this mean the signal has attenuated by 20dBm?

Also, when measuring this radiation pattern, is the receiver positioned at the 0-degree direction?

Thanks!

RE: The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

AllenDev — Thu, 22 May 2025 01:13:51 GMT

Dear Jonathan,

Thank you for taking the time to reply, it has given me a preliminary understanding of the antenna radiation pattern on the development board.

However, I would like to know if the radiation pattern and TX power would affect the IQ data collected during channel sounding for distance measurement. If so, why would it have an impact?

Thanks!

RE: The impact of the antenna radiation pattern of the nRF54L15DK on the IQ data in channel sounding.

JONATHAN LL — Wed, 21 May 2025 12:57:24 GMT

The orientation of the antenna will effect the results as the antenna does not hav uniform gain in all directions.

[quote user=""]1. I would like to inquire if there is an antenna pattern for the nRF54L15DK PCB.[/quote]

You are looking for the antenna gain ? or are you looking for the physicals shape of the antenna?

- we dont have measurements from the L15 DK but we do have from som older DKs and the antenna is the same so it should be similar.

devzone.nordicsemi.com/.../antenna_5F00_meas.zip

Unfortunately we only have the radiation pattern for the plane of the PCB (XY) plane, the DK was rotated and measured while laying flat. We therefore do not have any radiation pattern in the Z (upwards/downwards) direction, I hope it still can be of some use for you.

The reference level(outer circle) is 0 dBm, and there is a 20 dB/div (in all plots I think).

You could use a external antenna here if you wish with the connector on the RF path.

Regards,
Jonathan