IWR1642: IWR1642 Spurious Emission on 14.4GHz and 28.8GHz Issue.

Hi,

1. Can you confirm if the emission is on the boosterpack or a custom board 

2. Do you have any 2.4 GHz source on the board?

Regards,

Charles O

Sir,

This result is based on our board. But we can also find this 14.4G radiation at 1642's booster board as power on period for a while & reduce slightly.

Our board didn't have any further 2.4GHz source, but we can find 2.4GHz radiation over the limit of CISP25's 1G~2.5GHz limit. For this 2.4GHz, we can also always find at the booster board continuously.

JY

Hi Charles O,

 The issue has ever been raised in other post, https://e2e.ti.com/support/sensors/f/1023/p/740907/2737007#2737007, and Vivek Dham replied it might be relevant to DSP 600MHz CPU clock, since 2.4GHz could be 4th harmonic of 600MHz.

 Could you help to check if this true, and how to improve this?

Jesse.

Dear Sir,

This 14.4G radiation is based on PCBA power on only without configuration upload & TX output. May I know if this case is without DSP running right?

JY 

Sir,

In our PCBA, no shielding can be further added. So, we try to use the absorber to reduce this spur radiation as the attached picture. By the way, we found the maximum spurious radiation area is near the pin of A~H's 13~15. That is why we use absorber in this side only. However, this solution is not well for mass production. 

JY

In FCC Certification by AWR1443, we've had the same problem lately, and I wonder how the problem was solved. Please~ Let me know if there's a solution.