Electro Magnetic Applications, Inc. (EMA) and the Applied Research Institute (ARI) at the University of Illinois at Urbana-Champaign propose to continue the development and validation of a user-friendly software tool for the estimation of field distributions within rocket fairings 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 full-wave solver will include a rigorous mode and a sub grid mode. With the rigorous mode, the entire geometry will be meshed at the same fidelity, which was demonstrated to be feasible during the Phase I contract for fairings measuring 5 meters in diameter by 15 meters long up to 15 GHz. The sub grid mode will provide an option where the user can mesh part of the problem with a finer mesh and the rest of the problem at a coarser mesh. The results from the sub grid region (i.e., the finer mesh region) will drive the larger part of the problem while still capturing reflections from structures located inside the sub grid region. This capability will allow the user to trade off accuracy and run time when so desired. The full-wave solver computational engine will be ported to run on graphical processing units (GPUs). This hardware acceleration will allow for faster solution time and larger problems that can be solved with the full-wave tool. A series of measurements will be performed with a representative rocket fairing structure. Measurements performed will include shielding effectiveness, electric field distributions, antenna-to-antenna coupling, and antenna-to-cable coupling. Performing systematic measurements that build in complexity from an empty fairing to a fairing loaded with a payload, cable harnesses, acoustic blankets, and other components will provide valuable validation data for EMA3D Cable.
The resulting capability 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.
Commercial and other government agencies face similar challenges where antennas are located inside of fairings or radomes. For example, military radars can create dangerously strong standing fields inside of radomes that can start fires and cause interference to other avionics. Automotive radar companies need to understand how collision avoidance radars perform behind vehicle fascia.