To learn what factors are driving innovation in EMI and EMC testing, we at Evaluation Engineering asked a pool of electronic test & measurement vendors and partners about the trends, challenges, and customer demands they’re seeing, as well as what newer EMI/EMC test solutions they’ve put on the market. Here’s what they told us.
What’s trending?
What new or ongoing trends are vendors seeing among EMI/EMC receivers and amplifiers?
Dylan Stinson, RF products manager, and Alex Krauska, RF products system engineer at Tektronix: “While CISPR 16 compliant receivers are necessary for complying with EMI compliance standards, customers can get away with using non-CISPR 16 compliant real-time spectrum analyzers (RTSA) when performing their own in-house pre-compliance EMI testing. This allows product developers to rest assured knowing that their product is going to pass compliance in its first attempt through the compliance lab—reducing the chances of costly late-stage redesigns and trips to the test house.
“Most of the high-risk EMI tests are easily performed with low-cost RTSAs. The cost savings by performing troubleshooting and pre-compliance at your own facility can amount to hundreds of thousands of dollars and weeks or months of product delays. RTSAs have already proven to be invaluable for EMI debug and troubleshooting. Advanced spectral analysis will be especially important as mobile devices continue to shrink and more products incorporate wireless and other advanced digital modes.”
Jeremy Cline, product manager at Rohde & Schwarz North America: “The need for more insight into the source of potential interferer continues to grow, and simple pass/fail results are no longer sufficient. EMI receivers today also need to provide capabilities that help the developer to diagnose the signals and their origins. Real-time spectrum analysis allows for detailed investigation of disturbances. Persistence mode also allows identifying signals within signals, where narrowband interferers can be seen despite an overlaying broadband interferer. FFT-based time domain scan enables ultrafast measurements, which now allows designers to run their tests many times over and optimizing their design between tests. EMI receivers also continue to improve their RF performance and measurement accuracy. Exceptionally wide dynamic range, low DANL, high 1 dB compression point and high third-order intercept are required and expected.
“For power amplifiers, there is the continuous trend toward higher frequency coverage with same output power and level of VSWR handling. Solid-state technology has become the de-facto standard for broadband amplifiers and will eventually replace TWT tube technology that has poor reliability and production yields.”
Bill Stumpf, technical & laboratory manager at D.L.S. Electronic Systems: “Since FFT receivers have been accepted by CISPR standards, we see a push toward that capability in a continuing effort to increase measurement speed. Software and hardware functions are being added to try to keep pace with advancing wireless technologies.”
Challenges
As EMI/EMC technology continuously evolves, so do its challenges thrust upon vendors of such instruments. What key challenges are vendors of EMI/EMC receiver & amplifier facing today?
Cline, Rohde & Schwarz: “For receivers, providing wider bandwidths and higher frequency coverage continue to be major drivers. In addition to the hardware performance as described above, it has become crucial for vendors to also support their customers with tools and capabilities that give more insight into possible interferers. This also puts additional focus on usability aspects of EMI receivers. Today’s instruments not only need to meet and exceed the required hardware specifications, but they also need to come equipped with a variety of capabilities and an intuitive user interface that helps customers to go beyond pass/fail results to really understand where potential interferers are coming from.
“Complete EMC solutions are also becoming more complex; it is no longer sufficient to design a system for just one standard. Customers need the ability to test against multiple standards including ANSI, ETSI, and FCC. Co-existence tests are also becoming more relevant and a requirement for many customers. As a supplier, it is important to be able to offer a complete system of instrumentation including receivers, amplifiers, generators and other accessories designed for the use case of that customer.”
Stumpf, D.L.S.: “Keeping pace with advancing wireless technologies and associated test standards is a constant and difficult challenge for EMC test equipment manufacturers and test labs. As wireless and other product operating frequencies of go higher so will the requirements of EMC measurements.”
What are customers asking for?
Here are the features and other innovations today’s EMI/EMC receiver & amplifier customers are asking vendors to provide.
Stinson and Krauska, Tektronix: “As mentioned earlier, real-time capability over traditional swept significantly increases the likelihood of observing and recording short duration events. In addition to near-field E- and H-field probes, customers are asking for support of calibrated current probes—for measuring transient common-mode currents along cables and I/O ports. Customers are also asking for support of near-field TEM cells (TEM/GTEM/Crawford Cells) for desktop-size EMC testing. Low cost RF-shielded tents have also become very popular for pre-compliance.”
Cline, Rohde & Schwarz: “Receivers: Generally, customers are always faced with wider measurement bandwidth and the need to speed up their design—thus test time—and the need to identify potential interferers. Therefore, they need the ability to perform EMI debugging. This requires real-time spectrum analysis, persistence, and the ability to perform measurements quickly (FFT time domain scan). Amplifiers: Beyond output power and frequency range, customers we see are trending towards the more efficient use of broadband amplifiers. With ‘smart amplifiers’, amplifiers that can be tuned, customers can choose between maximum output power and high mismatch tolerance. For EMS applications, this allows the flexibility to increase the power of a given BBA130 amplifier up to 50%.”
Stumpf, D.L.S.: “Increased sensitivity, frequency range, function, and automation for specific compliance standards.”
Now on the market
Here’s what EMI/EMC receiver and amplifier solutions or features vendors told us they’ve recently made available.
“In addition to offering a powerful suite of real-time analysis tools that include advanced measurement displays such as density, spectrogram (waterfall), and others, Tektronix RTSAs are unique in that they provide Digital Phosphor Technology (DPX) swept display. This allows them to sweep wide (up to the instruments frequency range) and display density/persistence of interfering, intermittent, or signals under noise. Other real-time spectrum analyzers can only display persistence up to the real-time capture bandwidth of the instrument, a much narrower view. Swept DPX provides significantly enhanced measurement insight compared to traditional swept spectrum analyzers.
“Tektronix RTSAs are also unique in the fact that they are not mode-based analyzers, which require users to switch into different modes to operate in real-time or signal analysis mode. Instead, Tektronix RTSAs can acquire, measure, record, and display all at the same time, without leaving a gap in RF signal data.”
“Our focus on instruments with the RF performance and usability tools help identify possible interferers quickly and accurately. Our EMI receivers with fast scanning (FFT), real time spectrum analysis, and persistence mode are ideal tools to help identify and solve potential EMI and EMC challenges. Additional instruments such as our vector network analyzers, real-time-oscilloscopes, and signal generators are broadly used to solve signal integrity and power integrity challenges.”
Cadence: “The Cadence Sigrity technology product line is designed to help customers solve their most challenging signal integrity, power integrity, and EMI/EMC problems in IC packages, PCBs, and electronic systems. For example, our Sigrity Advanced SI package provides a complete power-aware system SI simulation environment for high-speed serial interfaces, such as PCI Express, HDMI, SAS, USB, etc. and high-speed parallel bus interfaces, such as those used in DDRx memory. The power-aware technology allows customers to simulate the impact of the power delivery network (PDN) on signal integrity, which is necessary in today’s high-speed interfaces.”
Applications (online only) What types of devices can these vendors’ EMI/EMC solution test?
Stinson and Krauska, Tektronix: “Common application devices include wireless modules (Bluetooth, WiFi, NB-IOT, etc.), power electronics or power supplies for automotive, computers, IoT devices, medical equipment, and military electronics. Tektronix’ RTSAs offer an extremely rich feature-set of both hardware and software for EMI troubleshooting and precompliance scanning—including commercial wireless standards testing, emissions testing, and first-power-on testing.”
Cline, Rohde & Schwarz: “Our test equipment, software and components address all radiated and conducted EMC testing for automotive, A&D, and commercial test. We can test just about anything electronic. We have a library of limit lines for both conducted and radiated tests for emissions and susceptibility-type testing. Whether customers want to perform precompliance or full-compliance measurements, we've got it covered. Our instruments have some of the best RF specifications in the industry and are built in deeply integrated automated factories to ensure quality. Rohde & Schwarz is putting complete test systems in place all around the world, coupled with regional support after the sale. When used with our EMC test software, our EMI and EMS test systems ensure that product testing will be fast and repeatable.”
