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

[AllenDev]

Dear Nordic,

I have a few questions I would like to ask.

1. I would like to inquire if there is an antenna pattern for the nRF54L15DK PCB.

    I have already searched through the related nRF54L15DK websites but could not find any relevant information.

2. Does the antenna pattern have an impact on the collected IQ data? Is there any relevant principle or explanation for this?

3.Currently, the nRF54L15DK only has a single PCB PIFA antenna. In my experiments, I observed that certain directions have a negative impact on the ranging performance.

    I would like to understand if this is related to the antenna's strength. If so, how can this be improved?

Thank you!

[JONATHAN LL]

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

1. I would like to inquire if there is an antenna pattern for the nRF54L15DK PCB.

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. 

antenna_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

[AllenDev]

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!

[JONATHAN LL]

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.

AllenDev said:

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

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