Title :
Equivalent lumped elements G, L, C, and unloaded Q´s of closed- and open-loop ring resonators
Author :
Hsieh, Lung-Hwa ; Chang, Kai
Author_Institution :
Dept. of Electr. Eng., Texas A&M Univ., College Station, TX, USA
fDate :
2/1/2002 12:00:00 AM
Abstract :
A transmission-line model is used to extract the equivalent lumped-element circuits for the closed- and open-loop ring resonators. The unloaded Q values of the ring resonators can be calculated from the equivalent lumped elements G, L, and C. Four different configurations of microstrip ring resonators fabricated on low and high dielectric-constant substrates are used to investigate the lumped elements and unloaded Qs. The largest difference between the measured and calculated unloaded Q is 5.7%, which is due to measurement uncertainties and accuracies of the calculation. These simple expressions introduce an easy method for analyzing ring resonators in filters and provide, for the first time, a means of predicting their unloaded Q
Keywords :
Q-factor; equivalent circuits; lumped parameter networks; measurement uncertainty; microstrip filters; microstrip resonators; permittivity; transmission line theory; calculation accuracy; closed-loop ring resonators; equivalent lumped elements; equivalent lumped-element circuits; filters; high dielectric-constant substrates; low dielectric-constant substrates; lumped elements; measurement uncertainties; microstrip ring resonator configurations; microstrip ring resonators; open-loop ring resonators; ring resonators; transmission-line model; unloaded Q; Accuracy; Circuits; Dielectric measurements; Dielectric substrates; Measurement uncertainty; Microstrip resonators; Optical ring resonators; Q measurement; Resonator filters; Transmission lines;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
