ASTM D3380

ASTM D3380 – Standard Test Method for Relative Permittivity (Dielectric Constant) and Dissipation Factor of Polymer-Based Microwave Circuit Substrates

Description:

Significance and Use

5.1 Permittivity and dissipation factor are fundamental design parameters for design of microwave circuitry. Permittivity plays a principal role in determining the wavelength and the impedance of transmission lines. Dissipation factor (along with copper losses) influence attenuation and power losses.

5.2 This test method is suitable for polymeric materials having permittivity in the order of two to eleven. Such materials are popular in applications of stripline and microstrip configurations used in the 1 GHz to 18 GHz range.

5.3 This test method is suitable for design, development, acceptance specifications, and manufacturing quality control.

Note 2: See Appendix X1 for additional information regarding significance of this test method and the application of the results.

Scope

1.1 This test method permits the rapid measurement of apparent relative permittivity and loss tangent (dissipation factor) of metal-clad polymer-based circuit substrates in the X-band (8 GHz to 12.4 GHz).

1.2 This test method is suitable for testing PTFE (polytetrafluorethylene) impregnated glass cloth or random-oriented fiber mats, glass fiber-reinforced polystyrene, polyphenyleneoxide, irradiated polyethylene, and similar materials having a nominal specimen thickness of ¹/₁₆ in. (1.6 mm). The materials listed in the preceding sentence have been used in commercial applications at nominal frequency of 9.6 GHz.

Note 1: See Appendix X1 for additional information about range of permittivity, thickness other than ¹/₁₆ in. (1.6 mm), and tests at frequencies other than 9.6 GHz.

1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.