Sensors forum

Kei

Part Number: IWR6843

Tool/software:

Hello,

I have a question about range bias and Rx channel gain/phase measurement by using "measureRangeBiasAndRxChanPhase".

The document* says, "The stated configuration profile (.cfg) must be used otherwise the calibration may not work as expected (this profile ensures all transmit and receive antennas are engaged among other things needed for calibration)."

There are several differences between the configuration for measurement and the configuration I want to use in the market.

For example, range resolution of the profile (profile_calibration.cfg) is 0.044m, but range resolution I plan to use in the market is 0.40 meters.
Is it acceptable for the chirp used for measurement to differ from the chirp I want to use in the market?

* C:/ti/mmwave_sdk_03_06_00_00-LTS/packages/ti/demo/xwr68xx/mmw/docs/doxygen/html/index.html

Regards,
Kei

11 months ago

0 zigang Yang 11 months ago

TI__Mastermind 39725 points

Hi, Kei:

This is a really good question. Let me do some research and get back to you later this week.

Best,

Zigang

0 zigang Yang 11 months ago in reply to zigang Yang

TI__Mastermind 39725 points

Hi, Kei:

Range bias depends on delay introduced from the following three sources:
1. the delay skew between the TX output and RX LO signal routing and
2. PCB delays (feed lines and radiation).
3. Delay in the receiver LNA

And the delay can change slightly from the RF frequency. That is why we would suggest you keep the same valid RF band (same RF start frequency and RF end frequency) between the calibration configuration and the application configurations.

Hope you can find this information helpful.

Best,

Zigang

0 Kei 11 months ago in reply to zigang Yang

Intellectual 750 points

Hi, zigang,

Thank you for your answer. I understand about range bias.

When considering the perspective of phase, what would the answer be?

Regards,
Kei

0 zigang Yang 11 months ago in reply to Kei

TI__Mastermind 39725 points

Hi, Kei:

The phase is also related to the phase. I would recommend to use the same RF bandwidth during calibration and final application.

Best,

Zigang

0 Kei 11 months ago in reply to zigang Yang

Intellectual 750 points

Hi, Zigang,

I understand but the term 'the perspective of phase' I used in the previous post means 'the perspective of phase correction between antennas'.
Range bias correction was mentioned but phase correction was not.
In this case as well, is your answer the same?

Regards,
Kei

+1 zigang Yang 11 months ago in reply to Kei

TI__Mastermind 39725 points

Hi, Kei:

I am not sure that I understand your question. It is the same answer for both range bias and phase calibration, you can use a different chirp for calibration, but try to make the RF bandwidth the same between the calibration chirp configuration and final application configuration.

Best,

Zigang

0 Kei 11 months ago in reply to zigang Yang

Intellectual 750 points

Hi, Zigang,

Thank you for your explanation. I understand.

Regards,
Kei