Two dimensional Bragg structures (modeling and experimental testing selective properties)

The analysis of electrodynamic properties of two-dimensional (2D) Bragg resonators of planar and coaxial geometry realizing 2D distributed feedback was carried out in the frame of the coupled-mode approach and in 3D simulations taken into account. High selectivity of above structures is demonstrated for large Fresnel parameters. Formation of the high-Q eigenmodes in the vicinity of the Bragg resonance frequency has been demonstrated and explained by peculiarities of the dispersion characteristics of normal waves. Parameters of the resonator when the Q-factor of the fundamental mode exceeds the Q-factor of all other modes is described. The results of 3D simulations of excitation of the fundamental mode by an external e.m. pulse using the 3D code Microwave Studio are presented. Results of the theoretical analysis corroborated by the data obtained in "cold" microwave measurements.