Analysis of Open-Ended Coaxial Probes by Using a Two-Dimensional Finite-Difference Frequency-Domain Method

A 2-D finite-difference frequency-domain (FDFD) method is presented to analyze open-ended coaxial probe problems. With the axial symmetry of geometry taken into account, the method reduces the original structure into an equivalent 2-D problem. Due to its ability to handle complex geometries, the presented method can tackle many practical situations when the analytical/semianalytical full-wave analysis is unfeasible. Numerical examples involving the infinite-flanged probes and the finite-flanged probes are included. In the examples of the infinite-flanged probes, the accuracy of the 2-D FDFD method and of the 2-D finite-difference time-domain (FDTD) method are checked with the results of the semianalytical full-wave analysis method. It is found that the accuracy of the 2-D FDFD method and of the 2-D FDTD method are the same, as long as their mesh structures are the same. In the examples of the finite-flanged probes, whose analytical/semianalytical full-wave analysis solutions are unfeasible, the results of the 2-D FDFD and 2-D FDTD methods are found to be in very good agreement. All the numerical examples show that the computational efficiency of the 2-D FDFD method is much higher than that of the 2-D FDTD method.