AWR1843AOP: About TX-RX antenna coupling around DC

Hi,

Thanks for posting. Could you let us know what market and end application you are targeting?

Thanks again,
Deexith.

Hello, 

Target application is short range radar for various objects and target market is all markets except automotive. 

Thanks, 

Shoko 

Hello Shoko,

If the target market is all markets except automotive, why is an AWR1843 being evaluated as opposed to IWR1843 or 60GHz IWR6843?

calibDcRangeSig can be enabled by setting the second field as shown above to 1. The fourth field is the positive bin Index, used to remove DC from closest range bins, which is the maximum positive range FFT index to be included for compensation.

This information can be found in the MMWAVE-SDK User guide, and after installed can be found at C:/ti/mmwave_sdk_03_06_00_00-LTS/docs/mmwave_sdk_user_guide.pdf

Best Regards,

Pedrhom

Hello Pedrhom, 

As you know, AWR1843AOP and IWR1843AOP are the same product. Therefore, I first evaluate AWR1843 which an evaluation board is available,

and then I will use IWR1843. 

I already know the overview and explanation of calibDcRangeSig. 

I would like to know a specific example of when to use calibDcRangeSig. 

I would like to know how to use calibDcRangeSig and HPF1/2 differently. 

Please advise. 

Regards, 

Shoko 

Hello,

All of the examples use calibDcRangeSig to some extent as long as it is enabled. There generally is not a reason to NOT use it unless for whatever reason the HPF is completely removing the antenna coupling while not filtering out legitimate detections for your setup. If you are still seeing antenna coupling in your point cloud you can increase the positive bin index. If you are constantly seeing reflection points very far away from the sensor, you can increase the magnitude of the negative bin index. The two HPF filters filter out indiscriminately, while calibDcRangeSig runs once at run time under the assumption the sensor is turned on with no legitimate objects in the scene. Otherwise the calibrated calibDcRangeSig may be higher than one might expect and it will end up over compensating.

Best Regards,

Pedrhom

Hello, 

Thank you for your explanation. 

I think calibDcRangeSig is useful function, but I also think it is difficult to use because DC term has temperature variation and it is difficult to calibrate without target. 

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1023157/awr1642-dc-term-will-increase-after-issue-calibdcrangesig-a-while/3835280?tisearch=e2e-sitesearch&keymatch=calibDcRangeSig#3835280

I have an additional question about calibDcRangeSig. 

Q) If calibDcRangeSig is enable, even if there is targets within negative/positive bin, it will not appear in FFT wavefor and will not work CFAR. 

Is my understanding correct?

Please advise. 

Best regards, 

Shoko 

Hello, 

Could you please provide an update? 

Regards, 

Shoko