Modeling of microwave ring resonators using the finite-difference time-domain method (FDTD)

Scattering parameters of microstrip ring resonators (with and without slits ) that are either edge or side coupled to the feedlines are simulated by th e FDTD method. The strip conductors on the device can either be infinitely thin or finite in thickness. The simulations predict the occurrence of reso nance peak splitting due to the simultaneous existence of magnetic and elec tric field coupling mechanisms. Excellent agreement was obtained between th e simulation results and the measured data for a ring resonator. We have al so shown that it si possible to use finite-difference time-domain simulatio ns to determine the dielectric constant of substrate materials. (C) 2000 Jo hn Wiley & Sons, Inc.