AFE7920: Unwanted spurious signal inside 3.5G receive path

YG Jeong

Part Number: AFE7920

Hi,

We're struggling with an unwanted spurious signal inside the 3.5GHz Rx path. Several tests have shown that the spurious signal is related to the JESD output rates (92.16M) in the receive chain.

The evaluation board was made by ourselves to check the AFE7920's performance. Other bands including 1.8G and 2.1G work well.

Chip initialization & handling has been done by Latte, or Firmware using API CAFE2p4.

If anyone has a similar experience or solution, could you let us know?

over 3 years ago

0 Kang Hsia over 3 years ago

TI__Guru 66004 points

Hi,

We have not observed any spur with related to the uplink data rate (RX data rate) of 92.16MHz. We have received your request from JH. We will definitely look into this further and get back to you.

-Kang

0 YG Jeong over 3 years ago in reply to Kang Hsia

Prodigy 160 points

Kang,

Thanks for your reply. Actually, the spurious signal comes on 3409MHz, which is 37 times the 92.16MHz. In our evaluation board, The JESD data rate is 184.32MHz, and we assume the data frequency is the half of data rate.

If we change the JESD data rate to another one, i.e. 245.76MHz, the spurious in the 3.5G band disappears. We've spent months to resolve this, but it's still not working. So please provide us with quick solutions and support. It's urgent.

Thanks.

0 Kang Hsia over 3 years ago in reply to YG Jeong

TI__Guru 66004 points

Hi,

Our apps engineer Eben would like to schedule a call with you. We have reached out to JH offline. Please advise JH on a convenient time for the call.

-Kang

0 YG Jeong over 3 years ago in reply to Kang Hsia

Prodigy 160 points

Thanks, Kang.

I'll contact JH.

0 Kang Hsia over 3 years ago in reply to YG Jeong

TI__Guru 66004 points

closing thread and going through offline discussion.

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AFE7920: Unwanted spurious signal inside 3.5G receive path