Effects of dimensions variation to the results of microstrip ring resonator method used on determination of dielectric properties

In this article, effects of dimension variation of the microstrip ring resonator structure to the determination results are experimentally studied. A measurement structure is presented, which includes several two-port microstrip ring resonators. The basic idea behind the determination of valued of dielectric constant is to design the microstrip line ring resonator structure to a certain main resonance frequency. The design is based on an estimated value of dielectric constant. If the measured resonance frequency deviates from the theoretically calculated value, the actual value of the material dielectric constant deviates from the estimated basing on the measured resonance frequencies and the dimensions of the microstrip line ring resonator structure. Determination of values of loss tangent in function of frequency is based on measured value of the loaded quality factor Q 1 and calculated value of the unloaded quality factor Q 1 at each resonance frequency