Simulation and measurement tools solve emissions problems
Courtesy of Computer Simulation Technology
Attention to EMC and related concerns should bracket your product development process, including the design of PCBs or components that will populate your product. Simulation can help avoid problems before a design is complete, and measurements can determine whether your design performs adequately at the prototype stage—helping to avoid costly and time-consuming iterative trips to the compliance test lab.
To help identify potential EMC compliance issues before a prototype is built, Computer Simulation Technology (CST) has introduced CST EMC STUDIO, which it highlighted at DesignCon in Santa Clara in January. CST EMC STUDIO contains a toolkit of solver technology for the study of EMC effects, including general-purpose 3-D modules for time- and frequency-domain simulation as well as specialized solvers, such as a 3-D transmission-line-matrix solver, which simplifies numerical EMC analysis using compact models and octree meshing. It supports bidirectional cable/field simulation to enable realistic modeling of noise propagation and radiation over cables. True transient electromagnetic circuit capability helps analyze the effect of nonlinear circuitry on EMC performance.
In addition to enabling engineers to study conducted and radiated emissions in consumer and related electronics products, CST EMC STUDIO can help them analyze susceptibility to ESD, lightning strikes, and high-intensity radiated fields.
The company notes that radiated and conducted emissions from PCBs can play a critical role in a product’s EMC performance. To help analyze printed electronics, CST EMC STUDIO includes an EMC rule checker, which allows the detection of potential PCB EMC problems that can be analyzed in 3-D by the software’s full-wave solvers. CST EMC STUDIO features an import function that supports PCB EDA formats such as those used in Cadence Allegro, Mentor Graphics Xpedition, and Zuken CR8000 as well as ODB++ databases.
“In the last few years, we’ve seen increasing interest in our products from the world of EMC analysis,” said Dr. Bernhard Wagner, managing director of CST, in a press release. “Through the development of simulation tools and specialized workflows specifically for this segment, numerical EMC analysis can be integrated earlier in the design process. With the introduction of CST EMC STUDIO, we further demonstrate our commitment to this field.” CST also is addressing EMC issues with the latest release of its CST STUDIO SUITE, from which many of CST EMC STUDIO’s solvers and tools have been derived.
Measuring EMC performance
Once you’ve developed a prototype PCB, you can observe its EMC and EMI performance using the EMxpert family of compact EMC and EMI diagnostic tools from EMSCAN. EMxpert can help you characterize your board and locate unintended radiators of RF interference in real time.
EMxpert includes a scanner on which you place your PCB under test; if your PCB is larger than the scan area, you can use the scanner to take multiple snapshots. It provides precompliance test to help you identify potential problems before compliance test, and it gives you spatial diagnostics information that an anechoic chamber couldn’t provide. It also performs cable testing, NFC antenna testing, and post-compliance test to help you identify issues discovered during compliance test.
EMxpert measures very near-field signals, but the company points out that everything that happens in the far field originates in the near field. The company offers the EMxpert-compatible Far-Field Application (developed by DVT Solutions, a provider of EMI, EMC, and ESD consulting services), which predicts (based on EMxpert near-field measurements) a PCB’s open area test site or semi-anechoic chamber radiated EMI levels in accordance with FCC, CISPR, and Industry Canada compliance limits at 10-m, 3-m, and 1-m distances.1
EMSCAN highlighted its latest EMxpert family member, the ERX+, at DesignCon. A high-resolution EMC scanner, ERX+ enables PCB and design engineers to diagnose EMC/EMI problems between 150 kHz and 8 GHz with seven different levels of resolution from 7.5 mm down to 120 μm. It incorporates a spectrum analyzer that can process 125 MS/s. Other members of the family include the EHX+ with a spectrum analyzer but not the high-resolution capability, and the EHX, a compact version that supports in situ testing of rack-mounted PCBs.
EMSCAN is a Keysight Technologies Solutions Partner for real-time PCB EMC measurement, and EMxpert works with a range of Keysight products, including the N9912A FieldFox RF analyzer, the N9340B handheld RF spectrum analyzer, and the E4402B ESA-E Series spectrum analyzers.
EMSCAN also announced that at the IEEE MTT-S International Microwave Symposium 2015 in Phoenix, Prof. Arturo Mediano will present a paper titled “Near-Field Scanner Demonstrations for RF/MW Engineers” on behalf of EMSCAN. Mediano is a member of the Group of Power Electronics and Microelectronics of the Aragon Institute for Engineering Research, a research institute of the University of Zaragoza in Spain. He serves as an instructor for Besser Associates, a provider of onsite and public courses for RF/microwave engineers, where he offers courses in EMI/EMC, signal integrity, and RF subjects throughout the United States and Europe.
Reference
1. Far-Field Application: EMxpert, EMSCAN, Preliminary Datasheet, May 2014.
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