Determination of parameters of VHF quartz crystal units equipped with evaporated electrodes using an Fr‐meter fixture

Abstract

AbstractThe Fr meter method is described as a method of measuring quartz crystal units in Appendix 1 of the Japanese Industrial Stand ard (JIS). When the resonance frequency and equivalent parameters of a quartz crystal unit are measured with the Fr‐meter fixture, an equivalent circuit based on four parameters has usually been employed. However, this equivalent circuit is not accurate for representing the impedance characteristic of the unit over a wide frequency range. to solve this problem, this paper offers an accurate method based on an equivalent circuit having five parameters for measuring the parameters over a wide range (from fs to fp) with the Fr meter fixture. the method is based on an equivalent circuit having five parameters.This paper describes the principle of the method; measurements of VHF‐band quartz crystal units; comparisons of the results with those obtained by using the drop method; and an examination of the repeatability of the method. the results show that the standard deviation of the resonance frequencies is within 2 × 10‐8, and the frequency agrees well with that obtained by the drop method. the characteristics between frequency and impedance of quartz crystal units calculated by using the parameters obtained agree well with those measured. It was confirmed that the proposed method with the Fr‐meter fixture could accurately measure the resonance frequency and the parameters of quartz crystal units.