Analysis of a UWB Hemispherical Antenna Array in FDTD With a Time Domain Huygens Method

Rotated Nonuniform Subgrids in the FDTD Method With Application to a Hemispherical Antenna Array

“…Figure 14 and Figure 15 and, again, reasonable agreement is obtained with discrepancies of approximately 5dB over much of the frequency range. The level of agreement is similar to that found using the method of [9]. In order to check for instability, the simulations were run for 16384 main grid iterations, a simulated time of 30ns, and no sign of instability was observed.…”

“…In order to do this efficiently, the details of each element are represented by the graded sub-grid shown in Figure 10 and Figure 11 which also show the material boundaries. The mesh used is similar to that used in [9] and the cell sizes are between 0.2mm and 0.47mm. These have been chosen so that the small features are covered by smaller cells and the positions of the cell boundaries are chosen for best accuracy.…”

“…For a conformal antenna array, this is another severe restriction. An example where this is an issue is the hemispherical array of slot antenna elements used in the MARIA breast cancer detection system, described in [8] and illustrated in Figure 1, which has been previously analyzed using other methods [8] [9].…”

Conformal antenna array modelling, FDTD predictions and measurements for Dual Circular Patch in Variable Geometry Conformal Antenna Array Test Rig

“…Bristol FDTD is an EM solver used within the university of Bristol for applications from Optics [6], to Medical Imaging [7]. Based upon the work by Yee et al [5] the model includes a variable FDTD mesh, which allows snapping of mesh lines to material boundaries for a more accurate model.…”

Rotated Subgrids in the FDTD Method

“…An example of this is the system described in [1] which is a hemispherical array of slot antenna elements designed for use in a breast tumor detection system. In [2] and [3], a method is presented whereby each element of the array is modeled using a Cartesian mesh which is orientated in the most appropriate way for that element. The results were then rotated so that they matched the orientation of the element in the array.…”