ADRV9009 RX out of band input issues

The LO is 2590MHz and the RF input is 2451MHz which means the Mixer out would be 139MHz and the corresponding image would be 2729MHz.

I could not understand where from 2697MHz is coming into picture. And when you change the LO frequency, the wanted and the image frequency as well gets changed.

The frequency component, 2697MHz that you are talking about is independent of LO frequency?

Have you enabled QEC, LO leakage calibrations?

vanitha said:

The LO is 2590MHz and the RF input is 2451MHz which means the Mixer out would be 139MHz and the corresponding image would be 2729MHz.

I am getting RF-input + Samplig-rate = 2451 MHz+ 245.76 Msps = 2696.76 MHz (approximately 2697 MHz), on tuning to LO: 2590MHz. I am not getting image at 2729 MHz (LO+Mixer = 2590+139=2729). Can you please check the same is true in your setup as well? 

vanitha said:

And when you change the LO frequency, the wanted and the image frequency as well gets changed.

We also observed the same, on changing the LO, the above mentioned frequency (2697 MHz) gets shifted to out-of-band-region. But when I open 2 LO bands: LO1 is 2590 MHz & LO2 is 2690 MHz consecutively, on giving input at 2451 MHz the 2697 MHz is visually falling in-band (on viewing the entire region of 2490 to 2790 MHz). How do I solve this? I did this multiple times, and the result is the same. Can you please check the same is true in your setup as well? If so, how to solve this issue?

vanitha said:

Have you enabled QEC, LO leakage calibrations?

Yes, I have enabled LO leakage calibrations & QEC.

Thanks & Regards

Goli Ganesh

We will get back to you shortly .

Hi vanitha ,


              Is there any update on this ?

Thanks and Regards

Goli Ganesh

The profile that you are using is 200MHz profile where in you can have RF signal with in LO+/-100MHz.

You cant feed RF at 2451MHz and this will get filtered by the filters in our receive path.

Hi vanitha ,


                   Thank you for the response.


    I understand that we are using 200 MHz profile and the range should be +/- 100 MHz. Although, in our test environment we need to feed 2451 MHz RF frequency at receiver but this is being reflected at 2696.76MHz. The LO set during this is 2590 MHz. This could be recreated on other setups we have as well by just setting LO at 2590MHz and feeding 2451MHz. Could you also please check on your side for the same testcase?

One more observation is that when I feed input frequency range between 2445 MHz to 2455 MHz, only then I am getting output at 2691.76 MHz to 2699.76 MHz when LO is tuned to 2590 MHz. In our application we want these signals to be filtered out. Please refer below image for better understanding. 

Thanks and regards,

Goli Ganesh.

You need to use external filters to remove the unwanted signals in your application . 

You cannot feed RF at 2451MHz and this will get filtered by the filters in our receive path because Talise supported max BW is 200MHz 

Hi vanitha ,

                  

vanitha said:

You cannot feed RF at 2451MHz and this will get filtered by the filters in our receive path because Talise supported max BW is 200MHz

  As expected the RF at 2451MHz should get filtered by the filters in ADRV9009 receiver path when LO tuned to 2590MHz, but it is not happening in our case and I'm getting a peak at  2696.76 MHz (approximately 2697 MHz).Can you please check the same if true in your setup as well? If so, how to solve this issue?

Thanks and Regards
Goli Ganesh

ADI  guarantees only the performance over the Primary BW of the selected profile and any additional spurs outside the Primary BW should be reduced/filtered by the external filters.