All,
FCC Rules, Section 15.33(b):
"(b) For unintentional radiators:
(1) Except as otherwise indicated in paragraphs (b)(2) or
(b)(3) of this section, for an unintentional radiator, including a digital
device, the spectrum shall be investigated from the lowest radio frequency
signal generated or used in the device, without going below the lowest
frequency for which a radiated emission limit is specified, up to the
frequency shown in the following table:
Highest frequency generated
or used in the device or on
which the device operates or Upper frequency of measurement
tunes (MHz) range (MHz)
Below 1.705 30
1.705 - 108 1000
108 - 500 2000
500 - 1000 5000
Above 1000 5th harmonic of the highest frequency
or 40 GHz, whichever is lower"
Note that if the highest clock speed is between 500 MHz and 1000 MHz, you
test to 5 GHz. Testing to the 5th harmonic (or 40 GHz, whichever is lower)
doesn't start until the clock is above 1000 MHz.
Ghery S. Pettit
Intel
-----Original Message-----
From: Dave Heald [mailto:davehe...@mediaone.net]
Sent: Thursday, October 25, 2001 1:09 AM
To: cecil.gitt...@kodak.com; emc-p...@majordomo.ieee.org
Subject: Re: EMC testing above 1GHz
Cecil,
Measurements above 1GHz are required for the FCC when your highest clock
exceeds 108MHz (top end of the FM radio band if anyone is wondering why
108). If the highest clock is between 108-500MHz, the scan goes to
2GHz. If it exceeds 500, the 5th harmonic. In practice, CPU core
frequencies count. Note that this does not apply to RF
transmitters/receivers or other intentional radiators which have very
specific and varied rules.
No measurements are currently required by the EU above 1GHz.
The FCC carries the limit lines at 960MHz (or thereabouts) all the way
to 40GHz. (except for transmitter requirements which vary greatly). One
HUGE difference is that the measurements above 1GHz should be made with
an average detector. This will typically get you a reduction of between
5-10db (or more!) compared to a peak detector. I had to force this
measurement method recently when I was told I had problems at 2.5 or 5
GHz. (of course, the lab took peak measurements and when they took
average measurements I was well below the limits and actually passed).
Testing is specified at 3 meters but can be reduced as needed for
sensitivity (S/N) issues.
Best Regards,
Dave Heald
> -----Original Message-----
> From: cecil.gitt...@kodak.com [mailto:cecil.gitt...@kodak.com]
> Sent: Tuesday, October 23, 2001 12:36 PM
> To: emc-p...@majordomo.ieee.org
> Subject: EMC testing above 1GHz
> Importance: High
>
> From: Cecil A. Gittens
>
> What are the EMC requirements for testing above 1 GHz in an Open Area test
> site?
>
> Cecil
-------------------------------------------
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/
To cancel your subscription, send mail to:
majord...@ieee.org
with the single line:
unsubscribe emc-pstc
For help, send mail to the list administrators:
Michael Garretson: pstc_ad...@garretson.org
Dave Heald davehe...@mediaone.net
For policy questions, send mail to:
Richard Nute: ri...@ieee.org
Jim Bacher: j.bac...@ieee.org
All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.
-------------------------------------------
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/
To cancel your subscription, send mail to:
majord...@ieee.org
with the single line:
unsubscribe emc-pstc
For help, send mail to the list administrators:
Michael Garretson: pstc_ad...@garretson.org
Dave Heald davehe...@mediaone.net
For policy questions, send mail to:
Richard Nute: ri...@ieee.org
Jim Bacher: j.bac...@ieee.org
All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.
