Does ADRV9008 DC offset calibration suitable in 5G with subcarrier at DC

One thing you can do is to offset the LO by SCS/2 so that LO falls in between subcarriers and then shift this back on FPGA. For example for SCS of 30KHz shift LO by 15 KHz.

Hi Vinod,

Thank you for your advice. I Think it's a good idea. So in your opinion the DC offset calibration is not suitable for 5G with DC subcarrier if we use drectly?

DC Offset cal will impact peak EVM for the subcarrier placed on DC.  You can disable digital DC offser using API adi_adrv9025_DigDcOffsetEnableSet() 

How about the RF DC offset cal?

Is the calibration mask bit D3 in the following table of ug1295 refer to RF or Digital offset Cal, or both?

I think both the RF and digital DC offset cal in initial Cal have no impact on DC useful signa because in initial sequence the RF radio is off. So I can enable the DC offset cal in init and disable it in tracking cal. Am I right?

MZhang683 said:

Is the calibration mask bit D3 in the following table of ug1295 refer to RF or Digital offset Cal, or both?

This is the RFDC offset. 

You can disable the digital DC offset tracking cal using the API adi_adrv9025_DigDcOffsetEnableSet() and then check the performance. You can also change the value of the M-shift using adi_adrv9025_SetDigDcOffsetMShift and check the performance.

Vinod,Could you help this question from MZhang683:I think both the RF and digital DC offset cal in initial Cal have no impact on DC useful signa because in initial sequence the RF radio is off. So I can enable the DC offset cal in init and disable it in tracking cal. Am I right?

Thanks a lot.

Sorry we were responding (API's suggested) , thinking that this is a ADRV9026 query .

RF DC offset will not impact the useful signal , but base band DC offset can impact. If after init cals , you disable DC offset cal with API TALISE_setDigDcOffsetEn() there will not be any impact to signal.

hirobertThank you!