All inductors (L) suffer from RF resonances, and are only effective in filters at frequencies not far above their first (parallel) resonance (see section 1.8.1 of [7]). But so-called ‘soft ferrites’ behave resistively at RF, and the resulting lack of RF resonances helps make filters that use them have better and more predictable performance at RF. For example, a typical small … [Read more...]
FCC Rules to Open Supplement Coverage from Space (SCS) to Assist Emergency Services
In March 2024, the Federal Communications Commission (FCC) adopted rules to facilitate the deployment of supplemental coverage from space (SCS). The new rules are intended to serve several important public interest goals for the Nation and expand the reach of communications services, particularly emergency services, so that connectivity and assistance are available in more … [Read more...]
NEMA Receptacles 5-20R with Ease of Assembly and More Power Performance
SCHURTER introduces the new NR520 series NEMA 5-20R outlets, adding to its existing range of 5-15R types. The new configuration extends the range of outlets rated 15 A to include a 20 A version for applications with increased power demands. SCHURTER’s NR520, which is the NEMA standard 5-20R [20 A at 125 V] configuration, complements SCHURTER’s existing range of outlets with … [Read more...]
Wireless Network Interference and Optimization
Introduction With the proliferation of embedded wireless systems in all imaginable products, comes the risk of increasing interference and resulting slowdown in data transfer. As we transition to a more mobile and connected society, the number of Wi-Fi (home appliances and control) and Bluetooth-enabled devices (speakers, headset, watches, etc.) is rapidly increasing. Add … [Read more...]
How to Choose Particle-Filled Silicones to Meet Multiple Design Requirements
Many electronic designs need shielding materials that combine resistance to electromagnetic interference (EMI) with other application-specific requirements. For example, the EMI gaskets that are used in military touchscreens need to attenuate EMI emissions, provide electrical conductivity, and ensure environmental sealing. These shielding gaskets also must also cushion the unit … [Read more...]
The Future of Shielding
THE FUTURE OF SHIELDING The future is not all that far off. With more electronic devices that are getting smaller, more portable and with continuing faster speeds, EMI or RF issues will continue to increase. There will be more integrated system-onchips (SoCs) where several functions will all be in one device that will need to be electromagnetically isolated. As an example, a … [Read more...]
Introduction to MIL-STD-464C
Responding to increasing criticism, Secretary of Defense William Perry issued a memorandum in 1994 that effectively eliminated the use of most defense standards. This has become known as the “Perry memo”. Many defense standards were canceled. In their place, the DOD encouraged the use of industry standards for quality assurance. MIL-STD-464 was developed as an “Interface … [Read more...]
The Industrialization of Satellites
Santa Rosa, California, December 28th, 2023 – The use of satellites in space has historically focused on the aspects of science, communication, and military. This will change massively in the future. Whole swarms of small satellites orbit the globe and supply mankind with Internet access. Modern day satellites are packed with state-of-the art electronics. They must be as small … [Read more...]
Design for EMC Compliance Essentials
Introduction While unrealistic to discuss all aspects of product design in a single article, I’ll try to describe the most common design issues I find in the hundreds of client products I’ve had a chance to work on. These issues generally include PC board design, cables, shielding, and filtering. More detailed information may be found in the Reference section below. As … [Read more...]
Using An Oscilloscope To Verify EMC Tests For Automotive Electronics
Consumer demand for more entertainment, safety, and communication options within automobiles has significantly increased both the density of electronic components and the number of on-board wired and wireless signals. The result: an ever-expanding range of signals contained within the same car-sized fixed space. USING AN OSCILLOSCOPE TO VERIFY EMC TESTS FOR AUTOMOTIVE … [Read more...]
