On analytic expressions for fast estimation of coupling between electrically short thin-wire antennas within cavities

Method of moment solutions for thin-wire antenna currents can turn to analytic solutions if the antennas are electrically small. This observation is useful for the analysis of interior problems of Electromagnetic Compatibility when transmitting and receiving thin-wire antennas serve to model electromagnetic sources and victims within a resonating environment. The analytic solutions allow fast evaluation of corresponding couplings but also are of limited accuracy. This is exemplified by the example of two coupled antennas within a rectangular cavity where coupling results between an analytical solution and an actual method of moment solution are compared.