ASTM D5568-22a PDF

Full title and description

Standard Test Method for Measuring Relative Complex Permittivity and Relative Magnetic Permeability of Solid Materials at Microwave Frequencies Using Waveguide — a non‑resonant waveguide-based S‑parameter test method for determining the complex dielectric (permittivity) and, where applicable, magnetic (permeability) properties of isotropic solid materials across radio‑frequency through millimetre‑wave bands.

Abstract

This ASTM test method (D5568-22a) specifies procedures that use rectangular (or, where applicable, circular) waveguide transmission-line fixtures and network-analyzer measurements to obtain relative complex permittivity (εr* = ε′ − jε″) and relative complex permeability (μr* = μ′ − jμ″) of isotropic, reciprocal solid materials. The method is non‑resonant, can be applied over a broad frequency span (approximately 100 MHz to beyond 40 GHz depending on waveguide size and equipment), and allows measurement of permittivity alone for non‑magnetic materials. Results are expressed in SI units and assume an e+jωt time convention; users must consider specimen geometry, fixture selection, and calibration to achieve reliable results.

General information

• Status: Active (current designation D5568-22a).
• Publication date: September 1, 2022 (amended/updated October 18, 2022 as D5568-22a).
• Publisher: ASTM International.
• ICS / categories: 17.220.01 (Electricity. Magnetism. — general aspects related to dielectric/magnetic properties).
• Edition / version: D5568-22a (revision of D5568-22).
• Number of pages: 9 pages.

Scope

This standard covers procedures for determining relative complex permittivity and relative complex magnetic permeability of isotropic, reciprocal (non‑gyromagnetic) solid materials using waveguide fixtures and network‑analyzer scattering‑parameter measurements. The method is applicable across a wide frequency range (approximately 100 MHz to over 40 GHz, subject to specimen size and waveguide selection) and is suitable for material research, design and quality control where broadband microwave dielectric and magnetic properties are required. It does not address safety requirements in detail; users should apply appropriate safety and environmental practices.

Key topics and requirements

• Measurement objective: relative complex permittivity (εr* = ε′ − jε″) and, where required, relative complex permeability (μr*).
• Test approach: non‑resonant transmission/reflection (S‑parameter) method using rectangular (preferred) or circular waveguide fixtures.
• Frequency coverage: approximately 100 MHz up to >40 GHz depending on fixture sizes and network analyzer capability.
• Specimen considerations: isotropic solid specimens, dimensions controlled relative to waveguide aperture; specimen machining and flatness affect accuracy.
• Instrumentation: vector network analyzer (VNA), appropriate waveguide sections/fixtures, calibration standards and de‑embedding techniques.
• Data processing: conversion of measured S‑parameters to complex permittivity and permeability using accepted inversion algorithms and corrections for fixture/sample geometry.
• Assumptions & limitations: media treated as isotropic and reciprocal; for non‑magnetic materials the method may be used to measure permittivity only; accuracy limited by sample preparation, calibration, and algorithmic assumptions.
• Units and conventions: SI units; harmonic time convention e+jωt specified in the standard.

Typical use and users

Common users include RF and microwave engineers, materials scientists, electromagnetic component designers, antenna and PCB material engineers, and test laboratories performing material characterization and quality control. Typical applications are characterization of dielectric substrates, composites, polymers, and ferrite or magnetic materials for component design, electromagnetic modeling, and verification of material specifications for telecommunications, aerospace, automotive radar, and industrial microwave systems.

Related standards

Standards and test methods commonly referenced alongside D5568 include: ASTM Test Methods D150 (dielectric constant and dissipation factor for solid insulation), other ASTM dielectric/permittivity methods and earlier D5568 editions, and international standards addressing permittivity/permeability measurements such as relevant parts of the IEC 62631 series and IEC/EN standards for microwave dielectric measurements (e.g., waveguide or resonator methods). Laboratories will often consult these documents when selecting the measurement approach best suited to frequency range, sample form, and accuracy needs.

Keywords

relative complex permittivity, dielectric constant, loss factor, loss tangent, magnetic permeability, waveguide, microwave, millimetre‑wave, S‑parameters, vector network analyzer, material characterization, isotropic materials, non‑resonant method.

FAQ

Q: What is this standard?

A: ASTM D5568-22a is a standard test method that specifies how to measure the relative complex permittivity and, if applicable, the relative complex magnetic permeability of isotropic solid materials at microwave frequencies using waveguide fixtures and network‑analyzer S‑parameter measurements.

Q: What does it cover?

A: It covers the non‑resonant transmission/reflection (waveguide) measurement procedure, specimen and fixture considerations, frequency applicability (roughly 100 MHz to >40 GHz depending on setup), data reduction to obtain εr* and μr*, and conventions for units and time dependence. It does not replace general safety or material‑specific test requirements.

Q: Who typically uses it?

A: RF/microwave engineers, materials researchers, test laboratories, manufacturers of dielectric and magnetic materials, PCB/substrate developers, and designers of antennas and microwave components who need broadband dielectric and magnetic property data.

Q: Is it current or superseded?

A: The document is the current ASTM designation D5568-22a (a 2022 revision with an amendment designation “22a” applied in October 2022). Users should confirm the edition and check for any later amendments or revisions before procurement or test planning.

Q: Is it part of a series?

A: D5568 sits within ASTM committee outputs addressing electrical and dielectric test methods (subcommittee D09.12). It is typically used in conjunction with other dielectric/permittivity standards and IEC/ISO methods that cover complementary frequency ranges, electrode techniques, or resonant measurement approaches.

Q: What are the key keywords?

A: Permittivity, dielectric constant, loss factor, permeability, waveguide, microwave, S‑parameters, network analyzer, isotropic, material characterization.