When electronics manufacturers started using increasingly higher-frequency devices and began implementing stricter EMC compliance standards, the pace of product introductions by EMI test and control companies kicked into overdrive. But, all these changes make it tough for you to stay up-to-date on developments in the EMC industry.
With that in mind, EE polled some of the EMC industry leaders to find out what recent product introductions incorporate technological breakthroughs, how you can be more productive, what current factors contribute to EMC product growth, and what trends are driving the EMC industry. These sages also gave us a glimpse of a product or service you should look for in 1998.
Technological Breakthroughs
Typically, technology advances are prompted by a market need, and the EMC industry is no different. It responds with the appropriate technologies for testing and controlling harmful EMI and RFI.
One such product is the surface-mount common-mode choke from Steward. Not only does it reduce emissions, but it also is made for use with today’s high-speed pick-and-place equipment.
Another technological innovation comes in the form of the Soft Knit Gasket from Instrument Specialties. It maintains conductivity after repeated use even in a corrosive environment, said Ron Brewer, vice president of EMC technical services at the company.
The XCELL™ from KeyTek is an advancement in the design of transverse electromagnetic (TEM) cells. Unlike single-polarization TEM cells that only rotate the product, the XCELL changes polarization by moving the antennas inside the cell. You accomplish vertical and horizontal polarization without moving the device-under-test.
A recent introduction from Antenna Research is the Scope 4600 which includes several EMI measurement functions in a portable form. It offers network-analyzer, spectrum-analyzer, and reflectometer capabilities in a small size that field engineers find valuable.
Productivity
Technical help for designers, seminars at customer sites, and consultations for design challenges are some of the services we offer, said Frank Rushen, president of Instrument Specialties. The company also has a new design guide catalog that will be put on the internet for customers.
Test-equipment manufacturers know you need cost-effective solutions and instruments with several features. “We offer multiple functions in a portable product,” said Pradeep Wahi, president of Antenna Research. “Our customers want more capabilities for automated testing that allow them to use one instrument for the whole frequency range.”
Combining features for several immunity tests helps you get your job done within budget, said Greg Senko, director of strategic marketing at KeyTek. The company is intimately involved with standards-writing organizations to ensure that well-justified and technically correct testing procedures are established. Soon after the creation of a standard, KeyTek publishes papers and application notes to educate you about what you need to do to meet the new emission and immunity requirements.
Contributors to Growth
Expect more digital processors to be used in automobiles and appliances
and information-processing equipment, said John Woody, advisor for research and marketing at Steward. Parallel to this development will be a growth of components used to suppress EMI.
The PCS and cellular markets will continue to grow, providing more opportunities for manufacturers of EMI/RFI test equipment, said Antenna Research’s Mr. Wahi. These markets have not fully matured and the products will continue to pollute the airwaves. Until the market reaches its apex, there will be issues about interference that must be resolved with control products and test equipment. An ancillary growth market will be electronic surveillance which uses equipment similar to that in the EMI/RFI test industry.
Another tendency to look for is the use of compact test chambers and transverse electromagnetic cells, said KeyTek’s Greg Senko. These smaller units are more cost- effective than the large and often very expensive anechoic chambers.
The financial health of the overseas markets will help shape the EMC industry. Global economies will improve in 1998, and U.S. companies will see more products purchased for offshore uses, said Steward’s Mr. Woody. The European and Southeast Asian economies have been depressed in recent years, compared to the U.S. economy, and they will pick up, causing a commensurate increase in the purchase of EMC products.
Growth in the EMC industry for 1998 will be driven by the European Medical Directive, said Mr. Rushen of Instrument Specialties. The implementation of the Medical Device Directive in June, 1998, with its EMC requirements, will increase testing of electronic products. In the United States, most medical equipment does not meet any EMC requirements, but all medical equipment sold in the European Union (EU) countries must follow the new certification process. As a result, many products on the U.S. market are being tested for EMI that might never before have been checked before.
Two years ago, there was a tremendous rush by electronics manufacturers to
comply to the EU Directive. In 1998, enforcement of the directive will be the major contributor to growth of the EMC industry, predicted KeyTek’s Mr. Senko. The EU members are beginning to demand that manufacturers comply with the directive. For example, the British recently drove home the importance of complying with the directive by initiating suits against companies that have not met the requirements of the law.
What to Expect in 1998
Companies typically hold their game cards close to their vests. So while the industry leaders EE questioned were appreciative of your need to know about their plans for 1998, they also were aware that they could be tipping their hand to the competition. But EE managed to get a peek at the direction some EMI-control companies will be taking in 1998.
Addressing the changes in the EMC standards and broadening the range of products and services will be a major thrust for KeyTek. The company also will continue supplying equipment for latchup testing and curve tracing of components.
More multifunction test equipment is on the horizon. For instance, Antenna Research will continue to offer EMI receivers and complete EMI immunity test systems.
However, the testers will be built around portable platforms with more software that makes them easier to use.
EMI/RFI Products
100-W Amplifier Covers
Frequencies to 1,000 MHz
The Model 100W1000 RF Amplifier delivers 100 W of continuous wave power from 1 MHz to 1,000 MHz. The minimum linear output power is 60 W over the entire frequency range, measured at a 1-dB gain compression point. Applications include RF susceptibility, antenna and component test, and watt-meter calibration. A front-panel analog meter displays forward and reflected power. Amplifier Research, (800) 933-8181.
Portable Analyzer
Measures to 1,000 MHz
The SCOPE 4600 is a portable spectrum analyzer for field or laboratory use. It performs broadband measurements with selectable resolution bandwidths to 1,000 MHz. The instrument has a lighted graphical LCD, built-in batteries and a charger, a PC interface for remote control, and a noise generator. The software keeps track of the calibrated test components attached to the SCOPE 4600 and provides the appropriate display for each test. Antenna Research, (301) 937-8888.
Antenna Combines Bilog and
Low-Frequency Technology
The CBL6140 X-Wing Bilog Antenna allows low-frequency power to be projected without affecting high-frequency elements. It performs RF immunity testing per the IEC 1000-4-3 requirements. The antenna uses a matching network, has an antenna factor of 3 dB @ 26 MHz, and handles power up to 500 W. Chase EMC, (441) 306 713 333.
Linear Power Amplifier
Features Test Functions
The EM-4246A-1 AMPLI-SYSTEM is a linear power amplifier featuring built-in digital control for EMI test applications. It has a 50-W continuous wave rating from 10 kHz to 1 GHz. The system provides digital displays of output power, output VSWR, and fault conditions via a GPIB interface and a front panel. Remote control of the amplifier gain and the output blanking is included. Automatic leveling using internal or external references supplies constant power to frequency outputs. Electro-Metrics, (518) 762-2600.
Gasket Combines Shielding
And Corrosion Resistance
Soft Knit Gaskets feature metallized nylon yarn over a UL94 VO-approved neoprene sponge elastomer. The surface resistivity for the silver-plated gasket is 0.045 W /in.2 at 20% deflection and 0.304 W /in.2 for tin-plated versions. Deflection cycling tests indicate no change in shielding effectiveness after 10,000 cycles. The compression set is <22% at 50% deflection. The gaskets are available in round, rectangular, square, and D- and C-fold profiles. Instrument Specialties, (717) 424-8510.
Test Cell Used for RF
Immunity Compliance Testing
The XCELL™ is an RF immunity and emissions test cell used for compliance and pre-compliance testing. The cell houses products up to 50 cm × 50 cm. It can change field polarization to accommodate position-sensitive equipment such as printers. The XCELL features a dual-symmetrical antenna, a fiber-optic lighting system, and a clamshell design. Applications include hand-held consumer products, medical equipment, and automotive devices. KeyTek, (800) 753-9835.
Anechoic Chamber Helps Meet
EU, ANSI, and IEC Requirements
The FACT 5 Free-Space Anechoic Chamber Test Site helps perform on-site, full-compliance EMI testing at 3 m and 10 m. The chamber dimensions are 59’ L × 39’ D × 26’ H. It meets ANSI C63.4, prEN 50147, and IEC 1000-4-3 testing requirements. Lindgren RF Enclosures, (630) 307-7200.
Conductive Envelope Uses
Pliable, Nonwoven Fabric
The Conductive Shielding Envelope is made from a pliable, metallized, nonwoven fabric for EMI shielding applications. It is corrosion and abrasion resistant with no increase in surface resistivity after 100,000 wear cycles per ASTM D3886. An integrated insulating layer protects sensitive components from an electrical short. The shape of the envelope can be changed to accommodate design variations. Finishing options for improved shielding include heat sealing, double-sided tape, and the company’s conductive fabric tape. Schlegel, (716) 427-7200.
Flexible EMI Gasket Uses
Silicone in Spiral Design
The Flexi-Shield EMI Gasket is a bonded, spiral-shaped, stainless steel and beryllium-copper material around a silicone tube or cord for EMI shielding and for rain, wind, and dust sealing. It resists compression set and is easy to handle. The gasket shows no visible wear after 1,000 insertions on a VME front panel. It provides 130-dB shielding effectiveness @ 1 GHz. The groove-mounted gasket flexes to conform to uneven joint surfaces. Cross-sectional diameters for the gasket range from 0.063″ to 0.125″. Spira, (818) 764-8222.
Common-Mode Choke Has
Surface-Mount Terminations
The CM-3422T600R Common-Mode Choke features a two-line configuration and standard surface-mount end terminations. Impedance is 135 W and reactance is 10 W at 1 GHz. The choke has a 6-A current-carrying capability, and the dielectric breakdown voltage is >500 VDC. Steward, (423) 867-4100.
Copyright 1997 Nelson Publishing Inc.
December 1997