Accurate Determination of Q Factors of a Quasi- Optical Resonator

This paper presents a novel approach to measuring the Q factors of a quasi-optical resonator used in a free electron maser (FEM) operating at 100 GHz. Estimation of the Q factors is based on measuring the reflection coefficient in the vicinity of resonance frequencies. The unknown parameters (attenuation constant and coupling inductance) are determined from the numerical solution of a nonlinear system of two equations. As an example, the Q factors of a quasi-optical resonator, based on the shorted-line waveguide section, have been determined using the proposed method. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 303–306, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10749