Modeling Platform Level Electromagnetic Compatibility Performance Based on Component Level Testing

Nearly every electronic module that is integrated into a Navy aircraft must pass MIL-STD-461 radiated emissions requirements (RE102), or Navy engineers must assess whether an exceedance of the radiated emissions limit is acceptable. To make a determination about a given exceedance, engineers must consider the specific emissions and how they could impact other electronic modules through coupling to cable harnesses, antennas, or directly to the other electronic modules. The process for assessing the impact is manual and often involves multiple engineers reviewing the details of the systems on the platform and potential interactions to reach a determination based on expectations and prior experience. In other words, the process is inexact and may result in interference to another system even after an engineering review deems the exceedance to be acceptable. On programs with little to no tolerance for risk, it may conversely result in lengthy and costly redesign work being performed even when the unit would have been successful integrated as-is onto a platform.  Numerical techniques have been developed for other electromagnetic applications for back projecting measured field data onto surfaces of a volume enclosing the device. The electric and magnetic fields on these near-field surfaces then represent the performance of the device. For example, this approach has been used very successfully for antennas. After the emissions data has been back projected onto the near-field surfaces, it can then be used in computational electromagnetic (CEM) simulation tools to compute coupling into cable harnesses, emissions from enclosures, and coupling to antennas on the aircraft.  EMA3D Cable is a mature simulation tool for addressing EMI/EMC problems and has been used in this capacity for decades to help military and commercial customers solve challenging problems. Through this effort, Electro Magnetic Applications, Inc. and the University of Illinois at Urbana-Champaign will collect measured radiated emissions data for several electronic devices and demonstrate numerical techniques to back project measured emissions data to near-field surfaces. Those can then be used in EMA3D Cable simulations to assess the impact of radiation emission exceedances on other electronic devices in an integrated platform.