DW3000 Product antenna delay calibration test Need to know the value of RTB antenna delay calibration?
Hi Jonas,
Can you share more detail on what product/device/board you have?
Usually there is a default antenna delay, but some of our boards are calibrated in the factory.
1 Like
HI Tiernanmc_DW
We use the DWM3000 development board as an RTB, and then we use the DW3000 solution on our products. Now need to calibrate the antenna delay of the product, need to know the antenna delay calibration value of RTB? Does this value need to be used for antenna delay calibration in later products?
Hi Jonas,
The DWM3000 modules are not calibrated for antenna delay in production, they only have crystal trim calibrated.
To use these boards as a Reference Test Board (RTB), you should first calibrate the transmit power to below regulatory levels and then calibrate the antenna delay on this board.
HI Tiernanmc_DW
See the attached photo.
Are these two development boards shipped without calibration of transmit power and antenna delay?
Hi Jonas,
QM33110EVB on the left is calibrated in the factory with antenna delay and txpower.
DWM3000EVB on the left is not, only crystal trim is calibrated.
To read back the OTP values you can use the API function:
// ------------------------------------------------------------------------------------------------------------------
// @brief This is used to read the OTP data from given address into provided array
//
// input parameters
// @param address - this is the OTP address to read from
// @param array - this is the pointer to the array into which to read the data
// @param length - this is the number of 32 bit words to read (array needs to be at least this length)
//
// output parameters
//
//no return valuevoid dwt_otpread(uint16_t address, uint32_t* array, uint8_t length);
Here is the OTP map to find the appropriate values.
I’d be cautious of putting too much trust in the delay calibration of any antenna on a connector.
A slightly loose connector can make a 5-10 cm difference in measured ranges.
Hi Andy,
You are correct!
These are calibrated using conducted method and a fixed offset added to compensate for the antenna. There will be variability across devices, which could be in the range of 5-10cm as you mention.
If user finds that the antenna delay is not accurate, then they need to adjust or re-calibrate to ensure they achieve their targeted accuracy.
HI Tiernanmc
We used two different development boards for distance test comparison, using IPOHE13 test.See the attached photo. There are two test results:
- The distance measured by the development board with nRF52840 keeps bouncing in the data displayed on the APP, with a tolerance of 5cm.
2.The distance measured by the development board with nRF52833 is normal.
The two different versions of the source program are downloaded from the QORVO official website, we do not understand why the test results are so different.
