Analysis of Propagation Between Rows of Conducting Cylinders That Model Solid Surfaces Using the Same Surface Area Rule

The thin-wire method of moments (MoM) is a useful technique for modeling a solid conducting surface by a grid of thin wires. Propagation between rows of conducting wires forming a waveguide is investigated to test this technique. A thick-wire model that allows for azimuthal current variation is also considered. When the total surface area of the wires equals the original solid-wall area, two things happen. First, the wire grid model and solid-wall waveguide have the same propagation constant β . Second, the thin-wire model erroneously predicts that the wire grid leakage is minimum whereas the thick-wire model predicts the correct behavior-that the grid leakage monotonically decreases with reduced wire spacing and/or increased wire diameter. The complex propagation constant between rows of conducting cylinders is calculated by using the matrix pencil method (MPM). The accuracy of this approach and the wire-grid modeling is verified using numerical and experimental results.