IWR6843ISK: TX power doesn't change in mmWave Studio

Timofey Savelyev

Part Number: IWR6843ISK

Dear experts,

I found a problem with changing TX power in mmWave Studio. Having configured my setup for 1TX / 4RX I tried various attenuation (Pwr Backoff) with steps of 10 dB and 3 dB, and the received signal power from a corner reflector remained always nearly the same. This holds for TX0 and TX1.

For TX2, Pwr Backoff is always locked at 0 dB. Is this a bug?

What is the actual transmitted power then?

Please see screenshots with my configuration and measured signals below.

Thanks.

Best regards,

Timofey

TX0 power backoff 0 dB:

TX0 power backoff 3 dB:

TX0 power backoff 9 dB:

Tx0 power backoff 20 dB:

TX1 power backoff 30 dB:

over 6 years ago

0 Timofey Savelyev over 6 years ago

Intellectual 590 points

A little confusion happened in the uploading. The first two screenshots belong to configuration TX2 / 4RX.

For TX0 / 4RX, please find screenshots below:

TX0 power backoff 3 dB:

TX0 power backoff 0 dB:

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to Timofey Savelyev

TI__Mastermind 25835 points

Hello,

Could you please show device connection tab and firmware used for this measurement.

Thanks and regards,
CHETHAN KUMAR Y.B.

0 Timofey Savelyev over 6 years ago in reply to CHETHAN KUMAR Y.B.

Intellectual 590 points

Hi,

please see below

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to Timofey Savelyev

TI__Mastermind 25835 points

Hello,

It appears that you are using older version of BSS firmware, i.e. BSS firmware version 6.0.5 doesn't have the TX back-off feature. It is available only in 6.0.6 and onward. You may need to download the latest SDK which has this support.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Timofey Savelyev over 6 years ago in reply to CHETHAN KUMAR Y.B.

Intellectual 590 points

Hi Chethan,

indeed I tried BSS v. 6.0.6 from the latest mmWave SDK v.03.01.01.02 and it worked well. Now I can control Pwr Backoff for Tx0 and Tx1 but Tx2 remains always locked at 0 dB.

Do you know how to change it?

in SDK v.03.01.01.02 I see only BSS firmware, so I am using older MSS from mmWave Studio v.2.0.0.2, see a screenshot below. Is this OK?

Thank you very much.

Timofey

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to Timofey Savelyev

TI__Mastermind 25835 points

Hello,

Thank you for confirming Power back-off is working on the latest SDK.

For the the TX2 you need to enable the Transmitters in the static configuration.

as shown below.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Timofey Savelyev over 6 years ago in reply to CHETHAN KUMAR Y.B.

Intellectual 590 points

Hi,

no, it's not that simple. Of course I tried 3Tx / 4Rx and Tx3 / 4Rx but Tx3 was always locked at 0 dB. Maybe a newer MSS firmware is needed, which is missing in the latest SDK?

BR
Timofey

0 CHETHAN KUMAR Y.B. over 6 years ago in reply to Timofey Savelyev

TI__Mastermind 25835 points

Hi,

Oh, Ok you are referring to T3 that is is grayed out on the GUI. That is the bug in the radar studio.
It's going to be fixed in the next revision of Radar studio (Release is planned in end of April-May time period).
Meanwhile you could use the LUA shell and issue LUA function API for using the 3rd Transmitter.

Thanks and regards,
CHETHAN KUMAR Y.B.

0 Timofey Savelyev over 6 years ago in reply to CHETHAN KUMAR Y.B.

Intellectual 590 points

Thank you.

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IWR6843ISK: TX power doesn't change in mmWave Studio