One of the major challenges in electronics system design is passing EMC testing, with the situation being so challenging that some companies build failed testing and redesigns into their budgets. High-reliability electronics deployed in defense systems are no different, with conformance to important EMI standards driving many aspects of system design. When EMC failures are found during initial testing, systems designers might find themselves in need of a costly redesign.
Connectors are a common point of EMI failure in rugged electronics, and a simple connector swap may not be enough to stop an EMI problem. The solution usually involves filters, which typically require changes on the PCB, connector pinout, and mechanical enclosure. To help solve these challenges, drop-in filters can offer a targeted approach, both for standardized and custom connectors.
EMI Challenges in Defense Electronics
Defense electronics face numerous EMI challenges due to their operational demands, often relating to how they must handle power and interface with other electronic systems. Defense electronics have strict environmental demands, as these systems must operate in extreme temperatures, high-vibration environments, and in all weather conditions. Connectors in these systems are a common failure point, both in terms of environmental exposure and EMI.
The two major operational EMI standards defense electronics standards must comply with are:
- MIL-STD-461: Specifies limits for electromagnetic emissions and susceptibility in military equipment.
- MIL-STD-464: Provides guidelines for electromagnetic environmental effects (E3) on systems and subsystems.
The former standard specifies conducted and radiated emissions limits as well as testing procedures for determining these emissions and susceptibility. The latter standard specifies compatibility requirements between systems and requirements for withstanding environmental electromagnetic effects, including electrostatic discharge (ESD).
When an EMC failure arises due to emissions from connector interfaces, the typical approach is to swap a connector for an alternative component, which will often be a shielded connector. One approach is to add in a filter adapter, which applies a filtering material between two mating connectors while providing exposed pins to pass power and signal. Finally, some designers may opt to look more closely at the PCB to determine where the EMI problem originates and implement any required design changes.
These options are always time-consuming and can incur substantial expense. For example, connector adapters are not available for all connector styles, and they may not have the required environmental ratings. Swapping for an alternate connector will force changes to the PCB and mechanical enclosures, effectively restarting the design cycle for a new product. To avoid such extensive redesigns, a drop-in solution in an existing connector is preferred.
How EESeal® Addresses EMI in Defense Electronics
Quell’s EESeal product offers a simple but cutting-edge answer to EMI challenges arising from connector interfaces. The EESeal product offers a targeted EMC solution in both standard and custom connectors, and adding EESeal provides EMI suppression without compromising the reliability of these connector options. EESeal is a drop-in filtering solution that is installed directly at the mating surface between two connectors, and it suppresses EMI by absorption of stray electromagnetic fields emitting from the mating surfaces.
EESeal’s drop-in capability provides significant advantages for standard connectors and custom connectors used in defense electronics:
Standardized connectors
For standard connectors, EESeal is a drop-in solution that fits in standard connector pinouts and form factors, which eliminates the need for costly, time-consuming redesigns on the PCB or the device enclosure. Supported connectors include D-sub, Micro-D, MIL-C-38999, MIL-C-5015, and MIL-C-26482.
Custom connectors
When excessive EMI is detected from a custom connector body, a drop-in EESeal product can be designed for a custom connector. Quell’s engineering team works closely with clients to develop custom EESeal designs that meet specific EMI and environmental requirements, providing support for new and legacy defense systems.
Most important is the ability of these connectors to withstand harsh environments, specifically exposure to extreme temperatures, vibration, and moisture. In many instances, adding EESeal to an IP6X rated connector will not affect the IP rating. This makes EESeal suitable for use in environments as varied as aerospace, naval, and ground-based military operations.
Conclusion
When EMC failures are placing pressure on schedules and budgets, EESeal offers a fast, reliable, and customizable filtering solution that can help get a new product through EMC testing without extensive redesigns or debugging. These standard and customizable filters offer a rugged drop-in option that meets the high standards required for defense applications.
When you have a challenging EMI problem that is preventing a product from getting to market, Quell’s drop-in connector filtering materials can provide a solution. The EESeal line of connector filter inserts ultimately helps companies get to market faster by eliminating additional testing and redesigns. Contact Quell today to learn more about EESeal filter inserts for radiated emissions, susceptibility, grounding, and transient protection.