Analysis of open-ended coaxial probe for EM-properties of curved surfaces materials testing by FDTD method

In this paper, an open-ended coaxial probe is studied using the standard FDTD technique to make nondestructive EM-properties testing of curved surface materials. The influence of the flange diameter and both convex and concave sample radii variations on the reflection coefficient is investigated. It is found from the results of error analysis performed using the FDTD method that the reflection coefficient is substantially affected for small radii of the convex sample while it is strongly affected by the flange diameter and concave sample radius. Results of the measured constitutive parameters ε* and μ* of the convex sample are compared and shown to be in agreement with published data. The results presented may be useful in the design of a modified coaxial probe for concave surface coating material testing.