Calculating Antenna Current Distribution Using the Method of Moments

Using the Method of Moments (MoM), we can calculate antenna current distribution, electromagnetic fields, radiation patterns, and impedance matrices. This numerical approach transforms continuous current distributions into discrete equivalent current elements through basis function expansion, enabling efficient matrix equation solutions. The implementation typically involves discretizing the antenna structure into segments, applying weighting functions, and solving linear systems of the form [Z][I] = [V], where [Z] represents the impedance matrix, [I] contains unknown current coefficients, and [V] denotes excitation voltages. Through current distribution calculations, we can predict antenna radiation characteristics and electromagnetic field distributions using integral equation formulations like the Electric Field Integral Equation (EFIE). The impedance matrix provides crucial input impedance information for antenna matching network design and transmission efficiency optimization. Key computational steps include: 1. Geometry meshing using triangular or rectangular patches 2. Selection of appropriate basis functions (e.g., pulse, triangle, or RWG functions) 3. Numerical integration for matrix elements calculation 4. Matrix inversion using LU decomposition or iterative methods In summary, the Method of Moments serves as a fundamental computational electromagnetic tool for antenna analysis, providing comprehensive insights for antenna design improvement through systematic numerical modeling of electromagnetic interactions.