How to deal with the power accuracy issue with nRF7002 and nRF7000?

[JoeFu]

Hi Nordic,

I test with nRF7002-DK and IC mark on nRF7002 is below:

N7002
QFAAB0
2252AA

 

Here is my test data, showing about a 3dB discrepancy between power setting and measurement power (left sheet). When I set a higher power, I also get a higher measurement power (right sheet). Therefore, I would like to ask if there is a calibration mechanism to ensure that when I set 16dBm, the measurement power is also 16dBm, or how to deal with the power accuracy issue? I believe that a difference of less than 0.5dB between the power setting and measurement power is reasonable. Otherwise, there will be issues with Tx certification due to mismatching between power setting and measurement power.

 

[JoeFu]

Hi Ketilijo,

Thanks for your feedback. I want to know AntGain is peak gain or average gain.

I can find how to set antenna gain. However, there is no way to set Kconfig value. Could you explain that?

[ketiljo]

Peak gain, as this will affect EIRP.

JoeFu said:

However, there is no way to set Kconfig value. Could you explain that?

Have you looked here? https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/protocols/wifi/regulatory_certification/antenna_gain_compensation.html#setting_antenna_gain_parameters

[JoeFu]

any update for this case?

[Amanda Hsieh]

JoeFu said:

The test results indicate the need for a calibration mechanism to adjust power levels.

What exactly does this mean? Can you clarify if you are worried that in 2.4GHz reading the achieved power is ~1.5dB lower than the set power? and hence think it needs calibration to get this error close to 0?

[JoeFu]

You are right!

[Amanda Hsieh]

But this is within the tolerance specification is ±2dB. Isn’t it?

[JoeFu]

Yes, specification is ±2dB. However, can you ensure all product specifications are within ±2dB? Currently, testing fewer than 10 pieces shows a deviation of -1.5dB, which easily exceeds the range. We also need to consider the PCBA trace in product applications which make more loss and let it out of spec. If you cannot provide a calibration mechanism, please let us know.

[JoeFu]

any update for this case?

[Amanda Hsieh]

Yes, unfortunately we do not have a closed-loop TX Power calibration mechanism in nRF70.