Method for Measuring the Q-Factor of Miniature Open Dielectric Resonators at Microwave Frequencies

Abstract

Questions of increasing the reliability of measuring high (greater than 5000) Q-factors of miniature open dielectric resonators are examined. A method for reliably determining the Q-factor of an open dielectric resonator is proposed along with an algorithm for determining the Q-factor of a resonator made of material with a tangent of the dielectric loss angle of less than 10 -4 in the shielded region. The algorithm is based on measuring the parameters of an electromagnetically coupled system of cavity metal and open dielectric resonators. The proposed method of determining the Q-factor of an open dielectric resonator is substantiated analytically in electrodynamic and circuit representations. Ways in which the metal volume affects the effective intrinsic Q-factor of an open dielectric resonator depending on its electrical characteristics are examined. The factors infl uencing the resulting effective Q-factor of an open dielectric resonator are evaluated and the range of expected measurement errors is indicated. The advantages of the proposed method of determining the Q-factor of open dielectric resonators are the high accuracy of the analytic relationships for determining the Q-factor, a lack of higher specifi cations on the accuracy in preparing the measurement sections and on the quality of the inner surfaces of the metal resonator, and the simplicity of the measurement process based on the use of ordinary equipment and components.