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Description / Abstract:
This guide provides information on construction of radiated
emission test facilities in the frequency range of 30 MHz to 40
GHz. Standardized site validation methods above 18 GHz remain
unavailable at present, however the changes in this edition are
considered appropriate guidance for use up to 40 GHz. In general,
the construction techniques described apply either below 1 GHz, or
for 1 GHz and above.
This guide does not address construction code compliance issues.
Parties responsible for the design and construction of test sites
are advised to consult with the various authorities having
jurisdiction (AHJ) to determine the building, HVAC, plumbing,
electrical, etc., codes and regulations that are applicable for the
test site.
In addition, beyond the similarity of basic principles, this
guide also does not specifically address considerations on
construction of test sites used for calibration of antennas used in
EMC radiated emissions measurements; that topic is covered in ANSI
C63.5.1,2 In addition, site-dependent measurement
instrumentation and signal cabling issues are not in the scope of
this guide.
Purpose
To account for the frequency ranges and differing measurement
needs as described in 1.1, this document provides construction
guidance focused on two applications:
a) At 1 GHz and below, the test site can be either an open-area
test site (OATS) or a semi-anechoic chamber (SAC).
b) At 1 GHz and above, the test site can be an OATS with
absorber material on a portion of the ground plane, a SAC with
absorber on a portion of the ground plane, or a SAC with absorbers
on all conductive surfaces; the latter test site is called a fully
anechoic room (FAR).3
Common construction techniques are also described that apply for
all the above test facilities.
NOTE—As a guide, this document does not contain requirements or
specifications because the material is meant to be informative.
However, some of the guidance should be strongly considered because
not taking the guidance can lead to a test site that does not meet
site validation requirements which are specified in such documents
as ANSI C63.4. On the other hand, some of the guidance identifies
what to consider among several options. As this guide is read, keep
in mind that there are these levels of consideration. The sense of
these levels of consideration as indicated by the verbs used is
given in the following list. A search of the document will show
where "should," "recommended," and "might" appear, the criteria
below will give the emphasis needed. Also, different from the usual
style for IEEE standards of marking annexes as normative or
informative, because all annexes in this document are informative
thus such marking is unneeded.
-"Strongly suggested" is identified by use of the verb
"should."
-Items "to be considered" are identified by the use of the
verb "recommended" or "might."
-"Is possible" is identified by use of the verb "can."
-There is no use of the normative verbs such as "shall"
and "must" in this guide.
1 For information on references, see Clause 2.
2 ANSI C63® publications are available
from The Institute of Electrical and Electronics Engineers
(http://standards.ieee.org/) or from the American National
Standards Institute
(http://www.ansi.org/).
3 Various other international and national standards
and open literature have used the acronym FAR to refer to fully
absorber-lined environments, i.e., shielded or unshielded chambers
or rooms having absorber material covering all internal surfaces in
their entirety. For the purposes of this document, FAR is used to
refer to a performance-based fully anechoic condition with
reflections reduced to below specified levels; see 5.4.