Study on the empirical design of open‐ended coaxial cavity resonator

Abstract

AbstractThis article is a study of an empirical design of an open‐ended coaxial cavity resonator. The coaxial cavity resonator can be designed using the coaxial transmission‐line theory. It can be done by using the radius of the inner conductor, the inner radius, and the length of the resonator. However, the basic coaxial transmission‐line theory can be seen that the characteristics of the resonant frequency and the Q value are varied by the change of length, regardless of the value of radius of the inner conductor and inner radius of the resonator. We find out the impact of radius of the inner conductor, inner radius of the resonator, and the length of the resonator parameter and propose the optimized empirical resonator design method by reducing the error between the theoretical value and the design value. High frequency structure simulator was used for simulation and the material of the resonator was designed with a copper. Based on the simulation, several resonators are fabricated by the size of 14 mm for the radius of inner conductor, 2, 5, and 10 mm, respectively, for the inner radius of resonator, and 8.5 mm for the length of the resonator. The resonant frequencies of the produced resonators were measured at 6.1, 5.7, and 6.5 GHz, respectively. According to the result of simulation and measurement, we know that we can design the relatively exact open‐ended coaxial cavity resonator by applying the basic coaxial transmission‐line theory directly when the length of the resonator is less than 10 mm, and adding the correction factor of 0.5 GHz to the calculated resonant frequency in case of more than 10 mm of the length of the resonator. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:606–610, 2014