Singularity Point in Effective Orthorhombic Medium Computed from Zero- and Infinite-Frequency Limit

We examine the position of singularity point by a defined difference function for the ORT model and derive the expression for the singularity point for ORT model within the symmetry plane. A two-layered ORT model is used to investigate the variation in position of the singularity point for the effective ORT model computed from zero- and infinite-frequency limit. Shown from the numerical examples, we find that the position of the singularity point is moving with the change in the thickness ratio between two ORT layers. The comparison for the singularity point between the effective ORT models from zero- and infinite-frequency limit is illustrated. The deviation in positions of the singularity point for the effective ORT model within the symmetry plane computed from zero- and infinite-frequency limit has also been investigated.