Re: Wireless RF IC's

On Nov 3, 5:38 pm, "Jon Slaughter" <Jon_Slaugh...@xxxxxxxxxxx> wrote:
Dave Platt wrote:
In article <hcq5eu$o2...@xxxxxxxxxxxxxxxxxxxxxxxxxx>,
Jon Slaughter <Jon_Slaugh...@xxxxxxxxxxx> wrote:

Yes but my product will be "commercial". i.e., it will be sold(not
in large quantities though... maybe 100/yr). How can I justify
making spending 10-20k$ just to add wireless capabilities and only
make potentially a few thousand?

As I understand it:  FCC certification (a.k.a. type acceptance) is
required at some point for devices which operate under Part 15

It's possible to buy RF communication modules (e.g. chip, antenna,
crystal, etc. all pre-assembled on a daughterboard) which have been
certificated by their manufacturer.  I believe that it's legal to use
a module of this sort in your device, without having to have your
device go through another round of certification testing, as long as
you don't modify the module.

yes, as I mentioned the one I was looking at.





               Makes no sense.  I can't understand why it would cost
so much(actually I'm not sure the cost but this is what I found
someone else saying) when the IC itself has already been FCC
approved and the antenna is really the only additional RF component.
It should be allowed that if one follows spec given in the datasheet
to be ok.

It's the FCC's position that the radio *system* is what is being
certificated - that is, the IC itself, any power amplifier stage after
the IC, and the antenna (and its support components).

An IC whose output was legal when used with one type of antenna, might
violate Part 15 limits (on power or ERP or spurious emissions) when
used with a different sort of antenna.

If you buy a module (system) and modify it in any way (e.g. with a new
antenna) you're responsible for certification of the final product.
If you don't modify the module, but use it in ways compatible with the
ways in which it was certificated, then [I believe] you're "good to
go" with no further testing.

Under a certain power limit and over a certain frequency it should
be free for commercial use since the range is extremely limited.

AAUI, it isn't just the power level at the design frequency that's at
issue.  It's whether the device/system can interfere... i.e. whether
it's violating the spurious-frequency emission limits.  This isn't
something that can necessarily be determined just from the IC's specs.

To me it sounds mainly like a way for them to get money(assuming those costs
are correct). If some company fabs and ic and creates a certain for testing
it and that circuit passes the FCC's tests then that circuit to almost exact
specs(anything within reason) should be valid.  The main issues are mainly
with the antenna design and the IC and just common sense with proper layout.

If it is so critical to keep noise down then they should designate a band
for commercial use but free to use without restriction. This way you use at
your own risk. The only requirement is that proper IC's and lay are used.
You can't enfore the layout but if the IC is correct then it should do most
of the job. Cause, after, all, what is preventing from someone not getting
certified and designing a good circuit?

The point being, is that some reason should prevail(but never does when
money is involved). Simply making a "one size fit's all" rule isn't very
practical. I understand their "goal" is to provide clean wireless comm but a
little bit of reason can go a long way. How bout the makers of the circuits
supply the model pcb layout that they used along with all the necessary
specs(pcb dielectric, passive values, etc.) and only modifications unrelated
to the rf section can be chained? Is that unreasonable? The devices could be
restricted to only be used on private property and not for roaming and also
for non-critical devices. This way it can be used on by businesses for their
own use. Because of the short distances it would be highly unlikely to cause
any drastic problems even if someone did screw something up big time.

If a device is limited to around 50m and even 90% within spec I doubt much
harm can come from it?

Of course I'm just learning about rf and maybe any slight change, such as
being 0.1% off on some passive's value, might cause some interference with
some plane 30k ft in the sky? Of course, then again there will always be
some genius to FTUBAR.

If it really is an antenna problem then one should be able to by self
contained FCC compliant antenna modules and then combine them onto the pcb
with their own design based around an FCC complaint IC's with no big
issues(here then it's only a connection matter and one of ground plains and
coupling cap's).

Somewhere there has to be some compromise. It seems to me, ignorant as I am,
that it's mainly just a "tax" on companies that develop any RF device. After
all, its a company so they can afford it and/or just pass on the cost to the
consumer.

My experience with the FCC is that there are two distinct parts. The
first part is the equipment authorization part. That is a process
done by the manufacturer and submitted to the FCC. If you look at
your wireless entry door lock device for your car, you will see FCC
ID: XXXXXXXXXXXX

if you go here:

http://www.fcc.gov/oet/ea/fccid/

you can find out a lot about any device that has an FCC ID associated
with it. For instance my car device is FCC ID : KOBLEAR1XT. The KOB
is the grantee code. every manufacturer gets a grantee code. KOB is
the "Lear" company code.

Anyhow, when a company wants to sell a product that radiates, they
need to get an equipment authorization (there are some exceptions to
this such as products sold as lab equipment) . It is up to the
company to do the neccessary testing to demonstrate that they are
compliant with FCC standards. You must decide what your device is
going to be used for and then get your authorization in accordance
with those rules. For instance, if you want to get an authorization to
sell equipment that transmits in the aviation bands, then you need to
go to part 87 rules and do all your testing in accordance with thise
rules. If you want to sell a device like a garage door opener (this
can be used by any unlicensed operator) then you need to look at the
part 15 rules. BTW part 15 is usually requires the most work to get
the authorization becuase it will be used by unlicensed people.

My point is, I do not think the chip manufacturer is involved in FCC
certification , except that their chips better allow the user of the
chip to pass his tests when he wants to manufacture a device using the
particular chips.

The second aspect to FCC policy is the end user. After the
manufacturer gets the right to sell equipment that can transmitt per
the authorization certificate, the user must have the license to
operate the equipment. So there are two parts to the formula.

Part 15 equipment does not require a licensed operator, but most stuff
sold does require a licensed user.

.

Relevant Pages

  • Re: Wireless RF ICs
    ... FCC certification is ... approved and the antenna is really the only additional RF component. ... with the antenna design and the IC and just common sense with proper layout. ...
    (sci.electronics.design)
  • Re: How much for Part 15, FCC Certified Low Power Station?
    ... How much is the equipment going to cost me? ... The most expensive part will be a decent antenna that complies ... to the FCC regulations of no more than 10' of antenna total.. ... AM Part 15 stations are capable of going a lot farther. ...
    (rec.radio.shortwave)
  • Re: How much for Part 15, FCC Certified Low Power Station?
    ... lower power stations. ... How much is the equipment going to cost me? ... The most expensive part will be a decent antenna that complies ... to the FCC regulations of no more than 10' of antenna total.. ...
    (rec.radio.shortwave)
  • Re: How much for Part 15, FCC Certified Low Power Station?
    ... lower power stations. ... How much is the equipment going to cost me? ... The most expensive part will be a decent antenna that complies ... to the FCC regulations of no more than 10' of antenna total.. ...
    (rec.radio.shortwave)
  • Re: How much for Part 15, FCC Certified Low Power Station?
    ... lower power stations. ... How much is the equipment going to cost me? ... The most expensive part will be a decent antenna that complies to ... the FCC regulations of no more than 10' of antenna total.. ...
    (rec.radio.shortwave)