Point Contacts in Modeling Conducting 2-D Planar Structures

Use of an optimization algorithm to improve performance of antennas and electromagnetic structures usually ends up in planar unusual shapes. Using rectangular conducting elements, the proposed structures sometimes have connections with only one single point in common between two neighboring areas. The single-point connections (point crossing) can affect the electromagnetic performance of the structure. In this letter, we illustrate the influence of point crossing on dipole and loop antennas using method of moments (MoM), finite-difference time domain (FDTD), and finite-element method (FEM) solvers. Current distribution, radiation pattern, and impedance properties for different junctions are different. These solvers do not agree in the modeling of the point crossing junctions which is a warning about uncertainty in using such junctions. However, solvers agree that a negligible change in the junction would significantly change antenna performance. We propose that one should consider bridging and chamfering of the conflicting cells to find optimized structures. This reduces the simulation time by 40% using FDTD modeling; however, no significant reduction is obtained using the MoM and FEM methods.