CC2538: CC2538 high frequency emission test

Lin Fiske

Part Number: CC2538

Dear Alex,

We are using the cc2538 per test firmware to do the high frequency emission test. The CC2538 is at 2475MHz Rx mode. The test is failed as shown in the attached document. It is surprised that there is no fundamental frequency 2475 MHz, but the second harmonic 4950 MHz present. Please comments. Besides, please tell us where are the 3222.659375MHz and 3256.000000MHz tone come from

17120501HKG-001 socket outlet - zigbee Rx above 1G.pdf

over 7 years ago

0 PM over 7 years ago

TI__Mastermind 27145 points

Hi,

This could be LO leakage.

We don't observe this issue on our EM Boards?

Did you follow our Reference Design in doing Schematic and PCB Layout?

If you don't follow our Reference design then this could happen.

If you want you can post your Schematic in PDF and PCB Layout in Gerbers for our Review.

Thanks,
PM

0 Lin Fiske over 7 years ago in reply to PM

Intellectual 690 points

Attached please find the schematic and gerberBUI-0058-EC-A Front PCB Schematics.PDF Gerber Files.zip

0 PM over 7 years ago in reply to Lin Fiske

TI__Mastermind 27145 points

Hi,

Yes, I am reviewing your files. I will send the review by COB today.

I don't see your email ID in your profile. Could you please update your profile with your email ID, so that I will send the review directly to your email.

Or if you don't mind you can post your email ID here. The choice is yours.

Thanks,
PM

0 Lin Fiske over 7 years ago in reply to PM

Intellectual 690 points

my email: pylin@grpdfond.com

0 PM over 7 years ago in reply to Lin Fiske

TI__Mastermind 27145 points

Hi,

OK, I sent the review to your email.

Thanks,

0 Lin Fiske over 7 years ago in reply to PM

Intellectual 690 points

The problem is solved by your solution. Thanks.

0 Lin Fiske over 7 years ago in reply to Lin Fiske

Intellectual 690 points

For antenna matching, should be include the harmonic filter or not include? That mean do the 50ohm antenna matching in A or in B (refer to attached file)

CC2538AntennaMatching.docx

0 Lin Fiske over 7 years ago in reply to PM

Intellectual 690 points

For antenna matching, should be include the harmonic filter or not include? That mean do the 50ohm antenna matching in A or in B (refer to attached file)

7610.CC2538AntennaMatching.docx

0 PM over 7 years ago in reply to Lin Fiske

TI__Mastermind 27145 points

Hi,

For Antenna Matching, you can use L3 and C42. Point B. No need to include Harmonic filter

Thanks,

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CC2538: CC2538 high frequency emission test