Common mode effects in high speed serial links

In production . of printed circuit boards (PCB) signal skew will be introduced in differential traces due to the weave effect. A skew that will vary from PCB to PCB. This signal skew generates mode conversion that together with poor common mode properties, along the high-speed channel, will degrade the system performance. For example, might the skew effect give a crosstalk much higher than the pure differential crosstalk. If the poor common mode properties in the channel are high and the skew can be expected to be high enough, the channel performance will be affected. Some PCB’s, with right combination of skew, might fail with too high bit error rate (BER) and other PCB’s will work.

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Grafen möjliggör höghastighetselektronik på böjbara material

En böjbar detektor . för terahertzfrekvenser (1000 gigahertz) har utvecklats av forskare på Chalmers med hjälp av grafentransistorer på plast. Det är den första i sitt slag, och kan utöka användningsområdet av terahertzteknik till tillämpningar som kräver böjbar elektronik, exempelvis trådlösa sensornätverk och kroppsnära teknik. Resultaten är publicerade i den vetenskapliga tidskriften Applied Physics Letters.

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Ögat på: EMC från bricka till bricka, del 20

EMC och skärmning, . del 3: Andra läckagevägar. EMC måste tas om hand i alla delar, såväl på elektrisk som på mekanisk systemnivå, och på alla nivåer i en utrustning på ett systematiskt och planerat sätt. Denna gång tittar vi på anslutningsdonens och anslutningskablarnas inverkan på EMC-skärmning.

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EMC FILTERS: Design, Selection and Installation of Power and Signal lines filters

Our former . eight EMC articles were aimed at familiarizing unaware readers with the fundamentals of EMI/EMC, justifying the EMC norms and testing, and explaining in simple terms the five basics interference coupling mechanisms, with the essential guidelines for controlling them. The present article goes deeper into one of the simplest, most compact and economical piece of the entire EMC arsenal: the filter. With current handling ranging from tens of Amp for signal filters up to more than hundred Amps for power line filters, they exist in all sorts of size, volume and packaging. They can be optimized against Common Mode (CM) or Differential Mode (DM) interference, or both.

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Aktuella trender inom EMC 

EMC-området . har alltid utvecklats i takt med den övriga teknikutvecklingen på marknaden. Denna utveckling fortsätter alltjämt och flera utvecklingstrender inom EMC kan ses på de internationella EMC-konferenserna. EMC för Internet of Things (IoT) är en sådan trend och där fokus bland annat ligger på behovet av att utveckla befintliga standarder för EMC-provning så att de dels är applicerbara på de nya frekvensband som IoT-produkter kommer att finnas i, dels har gränsvärden som är anpassade efter de täta samlokaliseringsavstånd som IoT-produkter bedöms få i framtida tillämpningar. 

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How to Perform EMC Testing of Autonomous Vehicles

EMC testing . of autonomous vehicles is challenging because the involved systems are designed to identify unrealistic driving conditions, which is exactly what we have in a typical anechoic EMC chamber. When the system detects unrealistic conditions, autonomous driving functions are disabled or set to predefined states, which means that EMC testing of autonomous functions is not possible. To fully test autonomous driving systems, we therefore need to emulate a realistic environment in many aspects, i.e., we need to stimulate involved sensors in a realistic way.

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Ögat på: EMC från bricka till bricka, del 19

EMC och skärmning, . del 2: Läckande skärmlåda. EMC måste tas om hand i alla delar, såväl på elektrisk som på mekanisk systemnivå, och på alla nivåer i en utrustning på ett systematisk och planerat sätt. Denna gång tittar på öppningars och spalters inverkan på EMC-skärmning.

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Coupling From and To the Power Mains – The 5th Coupling Path

Preamble . Our former EMC articles reviewed four of the 5 principal conduction and radiation coupling mechanisms, as they affect equipment/ system susceptibility and emissions. The last ones (EMC Articles #6 and 7) were addressing the shielding of equipment boxes, from the smaller hand-held devices up to large cabinets or even entire rooms. The present article is covering the 5th, very important coupling mechanism: How the various disturbances that exist on the power mains (public AC distribution, ship or aircraft AC distribution, vehicle dc distribution… etc) can find their way from their source down to the electronic components of a system?

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What Does the Future Hold for Positioning, Navigation and Timing?

In the past . 30 years, more and more devices have started using the US Global Positioning System (GPS) and related global navigation satellite systems (GNSS). This trend contributed to Europe’s decision to create its own system, Galileo, and this began offering initial services at the end of 2016. As well as Galileo, the Indian Regional Navigation Satellite System (IRNSS) now has a full constellation, and there are rapid developments in several commercial industries. So, 2017 promises to be an interesting year for developments in GNSS. Here are a few of the industry changes we expect to see this year…

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