ASTM D7449/D7449M-22

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 GHz 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 14-Mar-2022
• 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 − 22
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, health, and environmental practices and deter-
1.1 This test method covers a procedure for determining
mine the applicability of regulatory limitations prior to use.
relative complex permittivity (relative dielectric constant and
1.5 This international standard was developed in accor-
loss)andrelativemagneticpermeabilityofisotropic,reciprocal
dance with internationally recognized principles on standard-
(non-gyromagnetic) solid materials. If the material is
ization established in the Decision on Principles for the
nonmagnetic, it is acceptable to use this procedure to measure
Development of International Standards, Guides and Recom-
permittivity only.
mendations issued by the World Trade Organization Technical
1.2 This measurement method is valid over a frequency
Barriers to Trade (TBT) Committee.
range of approximately 1 GHz to over 20 GHz. These limits
are not exact and depend on the size of the specimen, the size
2. Referenced Documents
of coaxial air line used as a specimen holder, and on the
2
2.1 ASTM Standards:
applicable frequency range of the network analyzer used to
D1711 Terminology Relating to Electrical Insulation
make measurements. The size of specimen dimension is
limited by test frequency, intrinsic specimen electromagnetism
3. Terminology
properties, and the request of algorithm. For a given air line
3.1 For definitions of terms used in this test method, refer to
size, the upper frequency is also limited by the onset of higher
Terminology D1711.
order modes that invalidate the dominant-mode transmission
line model and the lower frequency is limited by the smallest
3.2 Definitions:
measurable phase shift through a specimen. Being a non-
3.2.1 relative complex permittivity (relative complex dielec-
*
resonant method, the selection of any number of discrete
tric constant), ε,n—the proportionality factor that relates the
r
measurement frequencies in a measurement band would be
electric field to the electric flux density, and which depends on
suitable. The coaxial fixture is preferred over rectangular
intrinsic material properties such as molecular polarizability,
waveguide fixtures when broadband data are desired with a
charge mobility, and so forth:
single sample or when only small sample volumes are
W
available, particularly for lower frequency measurements. D
* ’ ”
ε 5 ε 2 jε 5 (1)
r r r
W
ε E
1.3 The values stated in either SI units of in inch-pound 0
units are to be regarded separately as standard. The values
where:
stated in each system are not necessarily exact equivalents;
ε = permittivity of free space
0
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
W
= electric flux density vector, and
D
+jωt
assume an e harmonic time convention.
1.4 This standard does not purport to address all of the
W
= electric field vector.
E
safety concerns, if any, associated with its use. It is the
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 March 15, 2022. Published April 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2008. Last previous edition approved in 2014 as D7449/D7449M – 14. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D7449_D7449M-22. 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 − 22
3.2.1.1 Discussion—In common usage the word “relative” 3.3.3 cutoff frequency, n—the lowest frequency at which
is frequently dropped. The real part of complex relative non-evanescent, higher-order mode propagation can occur
’
permittivity (ε ) is often referred to as simply relative within a coaxial transmission line.
...

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.
Designation: D7449/D7449M − 14 D7449/D7449M − 22
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*
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 11 GHz 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 measurementsmeasurements.
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
+jωt
from the two systems is likely to result in non conformance with the standard. The 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.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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. 1, 2014March 15, 2022. Published December 2014April 2022. Originally approved in 2008. Last previous edition approved in 20082014
ε1
as D7449/D7449M – 08D7449/D7449M – 14. . DOI: 10.1520/D7449_D7449M-14. 10.1520/D7449_D7449M-22.
*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 − 22
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, and so forth:
W
D
* ’ ”
ε 5 ε 2 jε 5 (1)
r r r
W
ε E
0
wher
...