Brainstorm: Electromagnetic Compatibility
What are the most popular trends you see in EMC, and how do these trends pav the way for the reduction in electromagnetic interference?
William Stumpf, EMC Engineer, D.L.S. Electronic Systems
I see some trends in EMC that could reduce electromagnetic interference (EMI), and some that could increase it. Engineers seem more educated in the process of good EMC design, thanks to classes such as D.L.S.’s EMC By Your Design Seminars. Circuits that are designed and laid out correctly, proper termination of shielded cables, and well-designed enclosures all contribute to lower interference from digital electronics. However, two trends have the potential to increase EMC interference.
The first is related to digital technology. Circuits and microprocessors continue to increase in operating speed, switching power supply designs to be more efficient and more prone to higher emissions. Devices are ever more complex laden with multiple functions. The second is the proliferation of products that employ single or multiple wireless communication devices. Everyone wants to operate without wires, and more frequency bandwidth is being opened up for wireless communication.
Adding to the mix is that certified RF modules are easier to come by, and the integrator may not understand the possible effects of operating multiple radios in one product or in close proximity with other electronic products or wireless devices.
Chandarasekaran Krishnan, Principal Applications Engineer, Cima NanoTech
We lead high-speed digital lifestyles and own a growing range of high-tech electronic devices. As the performance of our devices increases, so does the communication speed between the chips on the integrated circuit (IC) boards. This leads to lower logic thresholds and noise margin, causing ICs to be more vulnerable to interference. The explosive growth of wireless multi-touch devices, from 4G smartphones to tablets, also leads to greater electromagnetic interference (EMI) challenges. Managing this interference is a major challenge, and EMC design consideration has become an indispensable part of product design and development to ensure that the final product has both form and function.
To achieve more effective EMI shielding performance, new methods and tools have been developed to reduce EM emissions and to increase the resilience of electronic components, interconnects, and subsystems within the device. However, effective EMI shielding performance alone is not sufficient and there is a growing need for EMI shielding solutions that complement market demands for lighter and slimmer products with touchscreens. As such, new lightweight, thin, and transparent EMI shielding materials that provide excellent shielding performance and can be cost-effectively integrated at the chip, package, board, cable, module, enclosure, and system level will be highly sought after. The availability of such materials will pave the way for greater adoption and reduction in electromagnetic interference.
Ryan Sadonis, Applications Engineer, Leader Tech, Inc.
At Leader Tech we have the opportunity to review and develop hundreds of custom solutions in regards to electromagnetic interference (EMI). One of our many solutions that address this issue comes in the form of a circuit board level shield. As most every EMI shielding company offers commercial off the shelf (COTS) shield components as a cost effective resolution to EMI, today’s trends seem to be last minute retro fit designs required to mitigate interference. The result is a costly shield due to complicated shapes, tooling, and short lead times needed to pass testing. An understanding of components or board layout designs that could be potential sources of noise or could be disrupted by EMI will allow engineers to design in real estate on the circuit board for potential shielding. This proactive approach will save time and costs during the critical prototype design phase a new project.
Other considerations that are trending today are the smaller sizes and lighter weight of today’s electronic technologies. As electronics become more compact they are also becoming hotter, and when considering shielding, engineers have to balance shielding performance vs. thermal relief. Thought should be given to this balance at the beginning of a design in terms of material choice, ventilation apertures and their relationship to operating frequencies and harmonics, and shield geometry. These considerations should take into account what the immediate need is and what the application may develop to be in the future, thus reducing design changes down the road.