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.
Benefit: The anticipated benefits to the Navy and eventual commercialization potential for the technology described in this proposal is tremendous. There are currently several general purpose commercial CEM solvers available. However, none of the commercially available solvers provide a capability for using measured radiated emissions data to create near-field sources that can then be used to predict radiation and coupling in complex platforms. Further, while other software companies perform consulting for clients, their consulting activities tend to be very limited. In contrast, EMA performs a great deal of consulting and measurement services. EMA staff will use the reverse propagation modeling capabilities in EMA3D Cable just like one of our customers. This will allow us to much more quickly identify salient features that can be incorporated into the product to improve accuracy, speed, and usability. EMA is currently selling EMA3D Cable throughout the United States using a channel partner network that serves virtually every major aerospace company. Today, EMAs customers purchase EMA3D Cable to rigorously solve lightning, HIRF, EMP and general EMI/EMC problems. With the reverse propagation modeling capability in EMA3D Cable, there would be a major opportunity to increase sales to existing accounts by offering a solution for integrating measured unit level radiated emissions data into a system level simulation. This would allow companies and organizations to make decisions informed with real data to determine if a unit exceeding its radiated emissions limit is acceptable or not. The need for the capabilities described in this proposal goes beyond aerospace customers. For example, the automotive industry also has a strict set of requirements that modules supplied by Tier 1, 2, and 3 vendors must meet. In those not-infrequent instances where radiated emissions or radiated immunity (as the radiated susceptibility requirements are known in that industry) are not met at the module level, Original Equipment Manufacturer EMC experts must make a determination whether to allow the product to proceed with integration or to request a redesign and incur additional costs and schedule impacts. With the increasing adoption of high voltage components for electric vehicle (EV) powertrains, issues with module level design can have ever greater impacts on eventual regulatory approval for each vehicle line. Having analytical tools available to aid in making the acceptance/redesign decision instead of leaving it to ad hoc judgement would be invaluable. This is a significant growth area for EMA and the technology described in this proposal.
Keywords: MIL-STD-461, MIL-STD-461, Electromagnetic compatibility (EMC), Huygens surface, reverse propagation, Radiated Emissions, Electromagnetic Interference (EMI)
