Numerical Simulation of Fields in Cavities with Detailed Antenna Modeling

Engineers at NASA are faced with the challenge of understanding complex electromagnetic effects that can impact payloads and launch vehicle hardware located under rocket fairings. Approximate approaches for modelingnbsp;antennas that interact with rocket fairingsnbsp;assume a plane wave incident upon the fairing for external antennas or a simple representation of the antenna (e.g., Hertzian dipole, simple monopole, etc.) for antennas located inside the fairing. However, in certain situations, the precise antenna radiation characteristics can have a large impact on propagation and the distribution of fields within the enclosure.nbsp;To further complicate matters, EMC engineers must often consider antennas in their analysis for which they do not have geometric or material details.nbsp;Electro Magnetic Applications, Inc. (EMA) and the National Institute of Aviation Research (NIAR) at the University of Wichita propose to develop a user-friendly software tool for the estimation of field distributions within large and small spacecraft enclosures due to antennas radiating internal and external to the enclosures. The tool will include a Power Balance (PwB) method solver, a full-wave three-dimensional solver, and a multi-conductor transmission line solver. The tool will be optimized to model antennas and will include features for reverse-engineering COTS antennas that are commonly encountered on NASA missions. Capabilities will also be developed to import existing antenna models from standard antenna simulation tools such as HFSS, CST, FEKO, and WIPL-D. The resulting tool will allow NASA analysts and eventually commercial customers to model field distributions and shielding effectiveness problems for rocket fairings due to internal and external antennas that are radiating prior or during a launch. This tool will be applicable during all stages of the design (from concept to launch) and will represent a major costs savings for NASA.