Improvement of the Standard Test Method for Effective Series Resistance (ESR) and Capacitance of Ultra High-Q Capacitors at High Frequencies

Ultra high-Q ceramic chip capacitors exhibit quality factors (Q) higher than 1000. The Resonant Coaxial-Line, manufactured by Boonton [1], has enough resolution for measuring such High-Q factors. As a result, in 1982, the resonant coaxial-line method was standardized by the American Society for Testing and Materials (ASTM) that issued the: “Standard Test Method for Effective Series Resistance (ESR) and Capacitance of Multilayer Ceramic Capacitors at High Frequencies” [2]. Applying this method, we found an error that concerns the measurement of a capacitor serially connected with a resonant coaxial-line and more particularly the frequency extrapolations that are mandatory for taking into account the skin effect [3]. Besides warning a user about an error, this paper is an opportunity to recall the principle of the resonant coaxial-line method and thereafter to present successively: the direct error free frequency extrapolation solution and the more complex procedure of the ASTM [2]. After comparison, the error that plagues the ASTM method is computed and is finally experimentally evaluated. Authors' note: In this paper, the symbols are identical to the ones specified by the ASTM [2].