ASTM D7449/D7449M-14

Standard Test Method for Measuring Relative Complex Permittivity and Relative Magnetic Permeability of Solid Materials at Microwave Frequencies Using Coaxial Air Line

SIGNIFICANCE AND USE
5.1 Design calculations for radio frequency (RF), microwave, and millimetre-wave components require the knowledge of values of complex permittivity and permeability at operating frequencies. This test method is useful for evaluating small experimental batch or continuous production materials used in electromagnetic applications. Use this method to determine complex permittivity only (in non-magnetic materials), or both complex permittivity and permeability simultaneously.
SCOPE
1.1 This test method covers a procedure for determining relative complex permittivity (relative dielectric constant and loss) and relative magnetic permeability of isotropic, reciprocal (non-gyromagnetic) solid materials. If the material is nonmagnetic, it is acceptable to use this procedure to measure permittivity only.  
1.2 This measurement method is valid over a frequency range of approximately 1 to over 20 GHz. These limits are not exact and depend on the size of the specimen, the size of coaxial air line used as a specimen holder, and on the applicable frequency range of the network analyzer used to make measurements. The size of specimen dimension is limited by test frequency, intrinsic specimen electromagnetism properties, and the request of algorithm. For a given air line size, the upper frequency is also limited by the onset of higher order modes that invalidate the dominant-mode transmission line model and the lower frequency is limited by the smallest measurable phase shift through a specimen. Being a non-resonant method, the selection of any number of discrete measurement frequencies in a measurement band would be suitable. The coaxial fixture is preferred over rectangular waveguide fixtures when broadband data are desired with a single sample or when only small sample volumes are available, particularly for lower frequency measurements  
1.3 The values stated in either SI units of in inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore each system shall be used independently of the other. Combining values from the two systems is likely to result in non conformance with the standard. The equations shown here assume an e+jωt harmonic time convention.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Oct-2014
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.12 - Electrical Tests

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7449/D7449M − 14
Standard Test Method for
Measuring Relative Complex Permittivity and Relative
Magnetic Permeability of Solid Materials at Microwave
1
Frequencies Using Coaxial Air Line
This standard is issued under the fixed designation D7449/D7449M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method covers a procedure for determining
bility of regulatory limitations prior to use.
relative complex permittivity (relative dielectric constant and
loss)andrelativemagneticpermeabilityofisotropic,reciprocal
2. Referenced Documents
(non-gyromagnetic) solid materials. If the material is
2
2.1 ASTM Standards:
nonmagnetic, it is acceptable to use this procedure to measure
D1711 Terminology Relating to Electrical Insulation
permittivity only.
1.2 This measurement method is valid over a frequency
3. Terminology
range of approximately 1 to over 20 GHz. These limits are not
3.1 For definitions of terms used in this test method, refer to
exact and depend on the size of the specimen, the size of
Terminology D1711.
coaxial air line used as a specimen holder, and on the
applicable frequency range of the network analyzer used to 3.2 Definitions:
3.2.1 relative complex permittivity (relative complex dielec-
make measurements. The size of specimen dimension is
*
limited by test frequency, intrinsic specimen electromagnetism tric constant), ε,n—the proportionality factor that relates the
r
electric field to the electric flux density, and which depends on
properties, and the request of algorithm. For a given air line
size, the upper frequency is also limited by the onset of higher intrinsic material properties such as molecular polarizability,
charge mobility, and so forth:
order modes that invalidate the dominant-mode transmission
line model and the lower frequency is limited by the smallest
W
D
measurable phase shift through a specimen. Being a non- * ’ ”
ε 5 ε 2 jε 5 (1)
r r r
W
resonant method, the selection of any number of discrete ε E
0
measurement frequencies in a measurement band would be
where:
suitable. The coaxial fixture is preferred over rectangular
ε = permittivity of free space
0
waveguide fixtures when broadband data are desired with a
single sample or when only small sample volumes are
available, particularly for lower frequency measurements
W
= electric flux density vector, and
D
1.3 The values stated in either SI units of in inch-pound
units are to be regarded separately as standard. The values
W
= electric field vector.
E
stated in each system are not necessarily exact equivalents;
therefore each system shall be used independently of the other.
3.2.1.1 Discussion—In common usage the word “relative”
Combining values from the two systems is likely to result in
is frequently dropped. The real part of complex relative
non conformance with the standard. The equations shown here
’
permittivity (ε ) is often referred to as simply relative
+jωt r
assume an e harmonic time convention.
permittivity, permittivity, or dielectric constant. The imaginary
”
1.4 This standard does not purport to address all of the
part of complex relative permittivity (ε ) is often referred to as
r
safety concerns, if any, associated with its use. It is the
the loss factor. In anisotropic media, permittivity is described
by a three dimensional tensor. For the purposes of this test
1
This test method is under the jurisdiction of ASTM Committee D09 on
Electrical and Electronic Insulating Materials and is the direct responsibility of
2
Subcommittee D09.12 on Electrical Tests. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2014. Published December 2014. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2008. Last previous edition approved in 2008 as D7449/ Standards volume information, refer to the standard’s Document Summary page on
ε1
D7449M – 08 . DOI: 10.1520/D7449_D7449M-14. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7449/D7449M − 14
method, the media is considered to be isotropic, and therefore descriptionincludesonlythosesystemsthathaveasynthesized
permittivity is a single complex number at each frequency. signal generator, and that measure the complex s
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D7449/D7449M − 08 D7449/D7449M − 14
Standard Test Method for
Measuring Relative Complex Permittivity and Relative
Magnetic Permeability of Solid Materials at Microwave
1
Frequencies Using Coaxial Air Line
This standard is issued under the fixed designation D7449/D7449M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1
ε NOTE—Equation 5 was editorially updated in March 2012.
1. Scope Scope*
1.1 This test method covers a procedure for determining relative complex permittivity (relative dielectric constant and loss) and
relative magnetic permeability of isotropic, reciprocal (non-gyromagnetic) solid materials. If the material is nonmagnetic, it is
acceptable to use this procedure to measure permittivity only.
1.2 This measurement method is valid over a frequency range of approximately 1 MHz to over 20 GHz. 20 GHz. These limits
are not exact and depend on the size of the specimen, the size of coaxial air line used as a specimen holder, and on the applicable
frequency range of the network analyzer used to make measurements. The practical lower and upper frequencies are limited by
specimen dimension requirements (large, thick specimens at low frequencies and small specimens at high frequencies). size of
specimen dimension is limited by test frequency, intrinsic specimen electromagnetism properties, and the request of algorithm. For
a given air line size, the upper frequency is also limited by the onset of higher order modes that invalidate the dominant-mode
transmission line model and the lower frequency is limited by the smallest measurable phase shift through a specimen. Being a
non-resonant method, the selection of any number of discrete measurement frequencies in a measurement band would be suitable.
The coaxial fixture is preferred over rectangular waveguide fixtures when broadband data are desired with a single sample or when
only small sample volumes are available, particularly for lower frequency measurements
1.3 The values stated in either SI units or of in inch-pound units are to be regarded separately as standard. The values stated
in each system mayare not benecessarily exact equivalents; therefore,therefore each system shall be used independently of the
other. Combining values from the two systems may is likely to result in non-conformance non conformance with the standard. The
+jωt
equations shown here assume an e harmonic time convention.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D1711 Terminology Relating to Electrical Insulation
3. Terminology
3.1 For definitions of terms used in this test method, refer to Terminology D1711.
3.2 Definitions:
*
3.2.1 relative complex permittivity (relative complex dielectric constant), ε , n—the proportionality factor that relates the electric
r
field to the electric flux density, and which depends on intrinsic material properties such as molecular polarizability, charge
mobility, etc.:and so forth:
1
This test method is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of Subcommittee
D09.12 on Electrical Tests.
Current edition approved Nov. 15, 2008Nov. 1, 2014. Published December 2008December 2014. DOI: 10.1520/D7449_D7449M-08E01. Originally approved in 2008. Last
ε1
previous edition approved in 2008 as D7449/D7449M – 08 . DOI: 10.1520/D7449_D7449M-14.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7449/D7449M − 14
W
D
* ’ ”
ε 5 ε 2 jε 5 (1)
r r r
W
ε E
0
where:
ε = permittivity of free space
0
W
= electric flux density vector, and
D
W
= electric field vector.
E
3.2.1.1 Discu
...