CC3220MODA: Power levels exceeded (spurs) during radiated emissions testing

Harold Wetzel

Part Number: CC3220MODA

Radiated emissions measurements were performed in CW mode on the CC3220MODA device. Several issues were observed where the limit was exceeded for radiated emissions as follows. Note that the emissions spurs occur every 812MHz which is Fo divided by 3. Although these spurs are not harmonics of Fo, they are harmonics of Fo divided by 3. Is TI aware of any potential issues in these frequency ranges, or can TI provide some guidance on possible causes for these power level issues?

2437MHz = Fo

4062MHz (Not a harmonic) 2xFo-812, over limit.

4874MHz = 2xFo, over limit by 2.4dB

5684MHz (Not a harmonic) 2xFo+812 in spec.

6498MHz (Not a harmonic) 2xFo-812, over limit by 5.8dB

7311MHz = 3xFo, over limit by 0.9dB.

There is something every 812MHz, you cannot see it between 2437MHz and 4062MHz because it is attenuated by the high pass filter.

over 3 years ago

0 FI over 3 years ago

TI__Mastermind 20210 points

Hi,

A colleague from HW team will get back on this as soon as possible.

Regards

0 Seong Kim over 3 years ago

TI__Mastermind 34715 points

Hi Harold,

We passed radiated emissions test when certifying the CC3220MODA. The test house used RadioTool to transmit using "continuous mode". Test results are available in our CC3220MODA certification reports which can be downloaded here.

This can also be caused by the layout. You can request a hardware review using this page.

BR,

Seong

0 Harold Wetzel over 3 years ago in reply to Seong Kim

Prodigy 45 points

When we used the continuous mode we applied an offset of -1 in the tool to be able to see the CW at maximum level.

If you do not add an offset in CW mode the carrier is still present but barely visible on the spectrum analyzer.

Will this -1 change in the offset in CW mode make the spurious peaks worse? Please give us your view on the effects of the offset change.

Thanks,

Harold

0 Harold Wetzel over 3 years ago in reply to Harold Wetzel

Prodigy 45 points

I haven't heard any follow up on the previous comment. Please respond as appropriate. Thanks.

0 Seong Kim over 3 years ago in reply to Harold Wetzel

TI__Mastermind 34715 points

Hi Harold,

The "Continuous Mode" I mentioned before is not CW as it is a modulated signal. See image below. Use this transmission mode for radiated emissions testing.

BR,

Seong

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CC3220MODA: Power levels exceeded (spurs) during radiated emissions testing