Radar Technology Pioneer Merrill Skolnik Dies at 94

IEEE also mourns the loss of a past IEEE Canada president and others

5 min read
Photo of a smiling man in glasses and a dark jacket.

IEEE Life Fellow Merrill Skolnik served as superintendent of the radar division of the U.S. Naval Research Laboratory in Washington, D.C., for more than 30 years.

IEEE History Center

Merrill Skolnik

First recipient of the IEEE Dennis J. Picard Medal

Life Fellow, 94; died 27 January

Skolnik served as superintendent of the radar division of the U.S. Naval Research Laboratory in Washington, D.C., for more than 30 years. While there, he made significant contributions including helping to develop high-frequency, over-the-horizon radar; a system that can identify friend or foe during combat; and high-resolution radar techniques.

For his work in the field, he was named the first recipient of the IEEE Dennis J. Picard Medal for Radar Technologies and Applications, in 2000. Picard was chief executive of Raytheon and helped the company become a leader in tactical missile systems.

Skolnik began his career in 1955 at MIT’s Lincoln Laboratory. While there, he taught a course on radar at Northeastern University, in Boston. The course was the basis for his 1962 book Introduction to Radar Systems.

He left MIT in 1959 to join Electronic Communications, now part of Raytheon. There he gained experience working on antennas, electronic warfare, and phased arrays.

He then joined the Institute for Defense Analyses, in Alexandria, Va. It provides technical advice to the U.S. Defense Department, the Defense Advanced Research Projects Agency, and other government entities. While there, he did pioneering work on thinned arrays and self-phasing array antennas. He also contributed to the fields of bistatic radars and electronic countermeasures.

In 1965 he became superintendent of the radar division at the U.S. Naval Research Laboratory. He and his staff developed concepts for wideband shipboard air-surveillance radar with reduced susceptibility to electronic countermeasures; self-defense radar; and space-borne radar for detecting ships.

He continued to work as a consultant for the lab after he retired in 1996.

In 1944 Skolnik joined the American Institute of Electrical Engineers, one of IEEE’s predecessor societies. He served on the Proceedings of the IEEE editorial board in the late 1980s.

He earned bachelor’s and master’s degrees as well as a Ph.D. in engineering from Johns Hopkins University, in Baltimore.

Wallace “Wally” Behnke

Director emeritus of the IEEE Foundation

Life Fellow, 96; died 11 January

Behnke spent his entire career at Commonwealth Edison in Chicago. He retired in 1989 as vice chairman of the utility.

He was an active IEEE volunteer and held several leadership positions. He served as the 1988 president of the IEEE Power & Energy Society. He was the 1990–1991 Division VII director, and he directed the IEEE Foundation from 1999 to 2004.

Behnke served in the U.S. Navy during World War II and the Korean War before joining Commonwealth Edison. During his tenure at the company, he oversaw the design and construction of the Clinch River Breeder Reactor project, a sodium-cooled nuclear facility in Tennessee.

He earned a bachelor’s degree in electrical engineering in 1945 from Northwestern University, in Evanston, Ill.

David John Kemp

1998 president of IEEE Canada

Life senior member, 78; died 5 January

Kemp worked for 35 years at the Manitoba Telephone System in Canada.

An active IEEE volunteer, he served in several leadership positions including as 1998 president of IEEE Canada and director of Region 7. He was IEEE secretary in 2000.

He was an IEEE member for nearly 60 years. He helped establish an IEEE student branch at Red River College, in Winnipeg, Manitoba. He went on to hold several officer positions in the IEEE Winnipeg Section. He helped launch the IEEE Graduates of the Last Decade program, now IEEE Young Professionals.

Kemp served on numerous IEEE boards and committees including the IEEE Service Awards Committee, the IEEE History Committee, the IEEE Life Members Committee, and the IEEE Canadian Foundation.

After he retired as director of information technology at MTS, he was the business manager of industrial applications at the University of Manitoba’s Microelectronics Center, in Winnipeg. He also worked as a consultant in Europe.

He served on the boards of the Electronics Industry Association of Manitoba and the Canadian Institute of Management.

Kemp earned a bachelor’s degree in electronics engineering technology from the Manitoba Institute of Trades and Technology, in Winnipeg.

Michel Poloujadoff

Recipient of the 1991 IEEE Nikola Tesla Award

Fellow, 89; died 13 December

Poloujadoff’s academic career spanned almost 40 years. His research focused on electrical machines, power electronics, and electrical lines.

He was an active volunteer in the IEEE France Section, and in 2004 he helped launch its IEEE Life Members Affinity Group.

He joined Grenoble University (now Université Grenoble Alpes) in France in 1961 as a professor of electrical engineering. He was a visiting professor in 1983 at McMaster University, in Hamilton, Ont., Canada. After returning to France, he became a professor of electrical engineering at the University Pierre et Marie Curie (now Sorbonne University), in Paris. He taught at the university until he retired in 2000.

Poloujadoff was a doctoral research advisor and mentored about 50 students during his career. He helped establish electrical engineering graduate programs in Egypt, France, and Tunisia.

He developed approaches for modeling squirrel-cage rotors—the rotating cylinder of steel laminations in induction motors—including harmonic magnetic fields and inter-bar currents. In 1965 he began conducting research on the numerical solution of electromagnetic field equations and later defined the basis of the first entirely 3D analysis of large transformers.

Poloujadoff authored five textbooks.

He served as chair of the France Section’s IEEE Life Members Affinity Group from 2004 to 2016. He was a distinguished lecturer for the IEEE Power & Energy Society and the IEEE Industry Applications Society.

After helping to found the International Conference on Electrical Machines in 1974, he served on ICEM’s steering committee from 1974 to 2000.

He received several honors including the 2012 ICEM Arthur Ellison Achievement Award, the 1994 IEEE Lamme Medal, and the 1991 IEEE Nikola Tesla Award.

Poloujadoff earned a bachelor’s degree in electrical engineering in 1955 from Supélec (now part of CentraleSupélec) in Paris. He received a master’s degree in computer science from Harvard. After returning to France, he earned his Ph.D. in electrical engineering in 1960 from the Université de Paris.

Edward F. Weingart

Vice president of engineering at AT&T

Life senior member, 86; died 26 November

During his career, Weingart worked at New York Telephone and Bell Atlantic (both now are part of Verizon) as well as AT&T. He retired in 1994 as AT&T’s vice president of engineering.

He was a pioneer in the wireless communications industry and helped launch cellular networks that are still used today. He holds several U.S. patents.

Weingart was a member of the U.S. Marine Corps Reserve.

Weingart’s family describes him as giving and community-minded. He was a member of several organizations including the Photographic Society of America, the Classic Car Club of America, and the Radio Club of America.

He earned a bachelor’s degree in electrical engineering from Polytechnic Institute of Brooklyn (now the New York University Tandon School of Engineering).

Antony Kenneth Spilman

Director at Arm

Member, 56; died 4 November

Spilman worked for several international technology companies in senior management positions. He was director of project management of open-source software at Arm, in England, when he died.

His family says he “always believed in building a strong team around him through supporting younger team members’ development.”

In his free time, Spilman enjoyed sailing, gardening, and skiing.

He earned a bachelor’s degree at the University of Southampton, in England, and a master’s degree at Stanford.

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The Inner Beauty of Basic Electronics

Open Circuits showcases the surprising complexity of passive components

5 min read
Vertical
A photo of a high-stability film resistor with the letters "MIS" in yellow.
All photos by Eric Schlaepfer & Windell H. Oskay
Blue

Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.”

From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor.

High-Stability Film Resistor

A photo of a high-stability film resistor with the letters "MIS" in yellow.

All photos by Eric Schlaepfer & Windell H. Oskay

This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film.

Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy.

15-Turn Trimmer Potentiometer

A photo of a blue chip
A photo of a blue chip on a circuit board.

It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety.

The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers.

Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film.

Ceramic Disc Capacitor

A cutaway of a Ceramic Disc Capacitor
A photo of a Ceramic Disc Capacitor

Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator.

A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage.

Film Capacitor

An image of a cut away of a capacitor
A photo of a green capacitor.

Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene.

The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value.

Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film.

Dipped Tantalum Capacitor

A photo of a cutaway of a Dipped Tantalum Capacitor

At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid.

Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use.

The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet.

Axial Inductor

An image of a cutaway of a Axial Inductor
A photo of a collection of cut wires

Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics.

Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor.

This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value.

Power Supply Transformer

A photo of a collection of cut wires
A photo of a yellow element on a circuit board.

This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet.

The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape.

The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current.

All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

This article appears in the February 2023 print issue.

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