FCC Certification Question (ATZB-S1-256-3-0-C)

Go To Last Post
17 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

The ATZB-S1-256-3-0-C is a wireless module (made by Atmel) built around the ATMEGA256RFR2.  It is a complete module, including both a ceramic chip antenna, and a small coaxial connector.  It also is FCC Certified.

 

I would like to use this module in my design.  As I understand it, I can transfer the module's certification to my design, and then only need to certify the whole design as an unintentional radiator.

 

Assuming this is true, I only have one problem: the coaxial connector on the board is a good 1mm taller than the rest of the module -- and I don't need it (using the ceramic chip antenna).  If I remove the coaxial connector, does that constitute a "change" to the module, and thus nullify its FCC certification?
 

Edit: typo

Science is not consensus. Science is numbers.

Last Edited: Thu. Aug 20, 2015 - 02:38 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

I don't know the real answer, but FCC has pictures of what was certified, so any visible modification will be noticed, that's for sure. So you would be taking a risk.

 

And yes, this connector is annoying.

 

 

NOTE: I no longer actively read this forum. Please ask your question on www.eevblog.com/forum if you want my answer.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Atmel used to have a few wireless modules that had only a ceramic antenna (no connector at all).  Example: ATZB-24-A2R

 

Why would they limit their catalog by not offering a connector-less equivalent of the ATZB-S1-256-3-0-C?

 

Has anyone ever had luck w/ "custom" orders from Atmel?  I'm willing to go w/ "large" minimum orders (10's of thousands) if necessary.  And by "custom" all I mean is the module exactly as is minus the connector (footprint could still be there -- just unstuffed).

Science is not consensus. Science is numbers.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

hobbss wrote:
Why would they limit their catalog by not offering a connector-less equivalent of the ATZB-S1-256-3-0-C?
I think that connector is used for testing, so not having it would require different test jigs. I know, it is a very weak argument.

 

hobbss wrote:
Has anyone ever had luck w/ "custom" orders from Atmel?  I'm willing to go w/ "large" minimum orders (10's of thousands) if necessary.  And by "custom" all I mean is the module exactly as is minus the connector (footprint could still be there -- just unstuffed).
But even if you manage to order them, they won't be certified if alterations are not allowed.

 

And for orders of 10's of thousands, it actually makes sense to ask your local sales rep.

NOTE: I no longer actively read this forum. Please ask your question on www.eevblog.com/forum if you want my answer.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Good point.  I guess I need to talk to a certification expert.

Science is not consensus. Science is numbers.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

Also, having thing that close to the antenna is not great in any case. Even if it is a plastic enclosure, the RF performance may degrade.

 

What exactly do you want to do with that 1 mm?

NOTE: I no longer actively read this forum. Please ask your question on www.eevblog.com/forum if you want my answer.

Last Edited: Thu. Aug 20, 2015 - 03:18 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I am definitely aware of that (have a lot stronger background in RF than embedded C!).  However, the impact is something I may need to deal with.   I am trying to retrofit this module in an existing case w/o needing to make mechanical modifications...

Science is not consensus. Science is numbers.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Unless changing the connector makes your device cause interference, and someone complains loudly, it is unlikely to ever show up on the FAA's radar once certified. Probably the only way they would ever be aware of you is if a competitor ratted you out.

 

Greg

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

It wouldn't cause any additional interference.  However, I want to make sure to follow the letter and intent of the law to avoid any possible issues down the road.

Science is not consensus. Science is numbers.

Last Edited: Fri. Aug 21, 2015 - 01:50 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

But the letter of the law is 4 thousand pages of impenetrable legal gobbledygook!

The largest known prime number: 282589933-1

In my humble opinion, I'm always right. 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

Torby wrote:
But the letter of the law is 4 thousand pages of impenetrable legal gobbledygook!
And as practice shows, it is very open to interpretation.

NOTE: I no longer actively read this forum. Please ask your question on www.eevblog.com/forum if you want my answer.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Fair enough.  But removing a component seems like a fairly straightforward issue.  I'll ask an expert...

Science is not consensus. Science is numbers.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

Intuitively you understand that removing a connector is not a big deal, but what if this connector introduced some attenuation that allowed to pass FCC? What happens if you remove some capacitor from a filtering network? That will obviously screw you up. I'm not sore if FCC makes a distinction between those two cases, but a comment from an expert would be nice.

NOTE: I no longer actively read this forum. Please ask your question on www.eevblog.com/forum if you want my answer.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

At Alex: I think you misunderstood me.  I agree with your viewpoint.  I meant that removing a component is straightforward from a compliance standpoint -- either it is allowed or not.  Because of the reasons you mentioned, I suspect it is not allowed.

That said, using my knowledge, I would be somewhat confident that removing the connector would not have a significant impact on radiation.  Therefore, I my main risk is cost -- i.e., my overall system would need to be certified as an intentional radiator (not transferring the Atmel cert.).  This is more expensive, but not quite as risky as developing my own module from scratch.

Science is not consensus. Science is numbers.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

I've just talked to a colleague and he made a good point. This connector is actually a switch, so if you simply remove it, the RF path will be  broken. You will have to put something in place of the connector. And also this specific connector has a non-symmetric landing pattern.

 

And while I can see how removing the connector is not likely to affect anything, putting something in place most definitely will.

NOTE: I no longer actively read this forum. Please ask your question on www.eevblog.com/forum if you want my answer.

Last Edited: Fri. Aug 21, 2015 - 08:28 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Definitely good points.  Thanks for the info.

Science is not consensus. Science is numbers.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

An extra mm, eh?  Sounds like a job for a Dremel tool, grinding wheel, and about 10000rpm.  ;)  (and don't get on me about the metal dust getting caught here-and-there and causing more problems...)

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.