FCC question

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Anonymous
Not applicable
We are struggling with a puzzling situation in a product weeks away from shipping. We are using an FCC certified module in our product and when we use the manufacturing firmware via UART, our Spectrum Analyzer output looks exactly like the expected waveform. (40db difference between the 2.4Ghz and side lobes), however when we use the module in normal mode, in Max Hold mode, we see unexpected big side lobs. We do not belive this is a mistake with our hardware design so we are really puzzled.

I have a few questions:

* Using manufacturing mode, we can easily pass FCC test but we are worried we will have a problem if somebody would pick our product and test in normal operation. Considering we have no previous experience passing FCC with this type of module and frequency, are we missing something? (i.e. are we worrying unnecessarily?)

* Could this be a bug in operational firmware (or BRCM firmware) whereby it amplifies the sidebands ince the BPF is not working or working in a way it is not optimal.

I would appreciate if you could comment.

I attached the two waveforms. Manufacturing mode, SA output and normal oepration SA output. These are taken with near field probes.

[ATTACH=CONFIG]172[/ATTACH][ATTACH=CONFIG]173[/ATTACH]
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5 Replies
Anonymous
Not applicable
Which country code are you using?

The country code determines power-per-rate and backoff in lower-middle-upper frequency bands.
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Anonymous
Not applicable
Which country code are you using?

The country code determines power-per-rate and backoff in lower-middle-upper frequency bands.

We are using USA. There are a few interesting observations. The problem manifests itself only in soft AP mode. The client mode is also clean like the FCC test application. Plus we see there is a 20dB(give and take) power difference between soft ap and client modes which we dont get.

We need a bit of guidance. We dont know where to look.
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Anonymous
Not applicable
Whos FCC certified module are you using?
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GregG_16
Employee
Employee
50 sign-ins 25 sign-ins 25 comments on KBA

Let us know if this is still an issue for you?

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Anonymous
Not applicable

Discussion is being locked. If you have any follow-up, please start a new discussion.

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