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Test equipment advancing to meet rapidly changing market needs

Although the rise of the IoT, 5G, and advanced automotive electronics markets is instigating rapid changes in technology, test equipment is keeping pace, and not just in extensions to bandwidth specifications or signal resolution. Maureen Lipps, Multicomp Pro Private Label Product Segment Leader, Test and Tools, Newark Electronics, runs through important advances in the industry and its tools.
Read the full article.

Smallest rugged AI supercomputer for avionics

Aitech Systems has released the A178-AV, the latest iteration of its smallest rugged GPGPU AI super-computers available with the powerful NVIDIA Jetson AGX Xavier System-on-Module. With its compact size, the A178-AV is the most advanced solution for artificial intelligence (AI), deep learning, and video and signal processing for next-gen avionic platforms.
Learn more.

Touchless angle sensors get CAN SAE J1939 interface

Novotechnik has added the CAN J1939 interface (developed for heavy-duty vehicles) to its RFC4800 Series of touchless angle sensors measuring angular position up to 360°, turn direction, turns, speed, and operational status. It can provide one or two output channels. It has a longer life and robustness than an optical encoder. It can signal if a sensor needs replacing or average a programmable number of values to output to reduce external noise if present. This is wear-free angle measurement made easy.
Learn more.

Radar level sensor monitors liquids and powders

The innovative FR Series non-contact radar level sensor from Keyence has been designed to monitor the level of both liquid and powder in any environment. This sensor features short- and long-range models, as well as chemical and sanitary options to address a wide array of level sensing applications. Works even when obstructions or harsh conditions are present, such as build-up, steam, or turbulence.
Learn more.

Raspberry Pi launches $70 AI Kit

Artificial intelligence (AI) is all the rage, and the makers of Raspberry Pi have created a way for enthusiasts of the single-board computer systems to take part and do a lot of experimenting along the way.
Read the full article.

3D model sharing at Brother Industries cuts rework

When Brother Industries, maker of printers, computers, and computer-related electronics, deployed Lattice Technology's XVL Player as a viewer for sharing 3D models throughout the processes of product design, parts design, mold design, mold production, and QA of molded parts, they reduced rework significantly -- especially from downstream departments. XVL Studio with its Difference Check Option helped address the rework in mold design, for example, by always keeping everyone informed of design changes.
Read this real-world case study.

What is 3D-MID? Molded parts with integrated electronics from HARTING

3D-MID (three-dimensional mechatronic integrated devices) technology combines electronic and mechanical functionalities into a single, 3D component. It replaces the traditional printed circuit board and opens up many new opportunities. It takes injection-molded parts and uses laser-direct structuring to etch areas of conductor structures, which are filled with a copper plating process to create very precise electronic circuits. HARTING, the technology's developer, says it's "Like a PCB, but 3D." Tons of possibilities.
Learn more (video included on page).

New! Thermoelectric dehumidifiers for enclosures

Seifert Systems has just introduced its line of compact Soliflex^® Series thermoelectric dehumidifiers, with or without condensate pump. These IP 56-rated units are designed to dehumidify enclosures and small control panels, can be used indoors or outdoors, and are maintenance free. When used with a hygrostat, Soliflex dehumidifiers will keep enclosure humidity below a defined level and only operate when needed.
Learn more.

More Stego enclosure heater options from AutomationDirect

Automation-Direct has added more Stego enclosure heaters to their Enclosure Thermal Management lineup. These new 120 to 240 VAC/VDC units include small, flat versions that distribute heat evenly within compact enclosures and are available with 8- or 10-W heating capacities. Also added are compact loop heaters that feature a patented loop body design for increased natural convection airflow, reduced thermal stress on the heater, and better heat transfer. Loop heaters are available in 10- to 150-W heating capacities.
Learn more.

Great design: Handle with integrated lighting/signaling

Signaling and indicator lights, switches, and buttons -- elements that hardly any machine can do without. The new JW Winco cabinet U-handle EN 6284 integrates all these functions into a single, compact element. The new U-handle is designed to enhance the operation of systems and machines. It features an integrated button and a large, colored, backlit area on the back of the handle. These elements can be used individually or in combination, providing a versatile tool for system control and process monitoring that can be seen from across the room.
Learn more.

Engineer's Toolbox: What is ground loop feedback?

Improper grounding can create problems in data logging, data acquisition, and measurement and control systems. One of the most common problems is known as ground loop feedback. Experts at CAS DataLoggers run through five ways to eliminate this problem.
Read the full article.

AI development kit for multi-camera products

The QCS6490 Vision-AI Development Kit from Avnet enables engineering teams to rapidly prototype hardware, application software, and AI enablement for multi-camera, high-performance, Edge AI-enabled custom embedded products. The kit facilitates design with the new, energy-efficient MSC SM2S-QCS6490 SMARC compute module based on the Qualcomm QCS6490 processor. Provides support for up to four MIPI CSI cameras and concurrent Mini DisplayPort and MIPI DSI displays.
Learn more.

High-temp cabinet cooler keeps incineration process in business

An EXAIR client company handles waste treatment on a large ship by operating an incinerator. The area where the incinerator is located gets very hot (over 120° F). This causes failures in the electronics package used to control the incineration process. Since compressed air is readily available, EXAIR's Model HT4225 Cabinet Cooler System is being used to keep the panel cool. It saved the customer from having to replace their control units due to the hot conditions in the incinerator room. Thermostat control is also available, conserving air and operating only when needed to minimize air consumption.
Learn about EXAIR's huge selection of Cabinet Coolers.

Compact snap-in capacitors for general-purpose applications

TDK's new EPCOS B43659 series of snap-in aluminum electrolytic capacitors is the next generation of ultra-compact, general-purpose components for voltages of 450 V (DC) featuring an extremely high CV product. It provides the same features and serves the same applications as the previous series but is much more compact. These RoHS-compliant capacitors can be used in a wide range of applications, such as switched-mode power supplies, frequency converters, UPS, medical equipment, and solar inverters.
Get all the specs.

Conductive Brush Ring overcomes current leakage in EV powertrains

SKF's new Conductive Brush Ring paves the way to greater reliability and longer life in high-performance electric vehicle powertrain systems. Using pure carbon fiber bristles, it provides a reliable electrical connection between an EV eAxle rotor shaft and its housing. When used in combination with SKF Hybrid ceramic ball bearings, it helps to alleviate parasitic current effects that can lead to premature failure in bearings and other components. Available in different configurations for wet (oil-lubricated) motor designs -- and soon for dry (sealed) applications.
Learn more.

Tiny terahertz laser could be used for imaging, chemical detection

A new technique boosts the power output of tiny, chip-mounted terahertz lasers by 88 percent. [Image: Demin Liu/Molgraphics]

 

 

By Larry Hardesty, MIT

Terahertz radiation -- the band of the electromagnetic spectrum between microwaves and visible light -- has promising applications in medical and industrial imaging and chemical detection, among other uses.

But many of those applications depend on small, power-efficient sources of terahertz rays, and the standard method for producing them involves a bulky, power-hungry, tabletop device.

For more than 20 years, Qing Hu, a distinguished professor of electrical engineering and computer science at MIT, and his group have been working on sources of terahertz radiation that can be etched onto microchips. In the August issue of Nature Photonics, members of Hu's group and colleagues at Sandia National Laboratories and the University of Toronto describe a novel design that boosts the power output of chip-mounted terahertz lasers by 80 percent.

As the best-performing chip-mounted terahertz source yet reported, the researchers' device has been selected by NASA to provide terahertz emission for its Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) mission. The mission is intended to determine the composition of the interstellar medium, or the matter that fills the space between stars, and it's using terahertz rays because they're uniquely well-suited to spectroscopic measurement of oxygen concentrations. Because the mission will deploy instrument-laden balloons to the Earth's upper atmosphere, the terahertz emitter needs to be lightweight.

The researchers' design is a new variation on a device called a quantum cascade laser with distributed feedback. "We started with this because it was the best out there," says Ali Khalatpour, a graduate student in electrical engineering and computer science and first author on the paper. "It has the optimum performance for terahertz."

Until now, however, the device has had a major drawback, which is that it naturally emits radiation in two opposed directions. Since most applications of terahertz radiation require directed light, that means that the device squanders half of its energy output. Khalatpour and his colleagues found a way to redirect 80 percent of the light that usually exits the back of the laser, so that it travels in the desired direction.

As Khalatpour explains, the researchers' design is not tied to any particular "gain medium," or combination of materials in the body of the laser.

"If we come up with a better gain medium, we can double its output power, too," Khalatpour says. "We increased power without designing a new active medium, which is pretty hard. Usually, even a 10 percent increase requires a lot of work in every aspect of the design."

Big waves
In fact, bidirectional emission, or emission of light in opposed directions, is a common feature of many laser designs. With conventional lasers, however, it's easily remedied by putting a mirror over one end of the laser.

But the wavelength of terahertz radiation is so long, and the researchers' new lasers -- known as photonic wire lasers -- are so small, that much of the electromagnetic wave traveling the laser's length actually lies outside the laser's body. A mirror at one end of the laser would reflect back a tiny fraction of the wave's total energy.

Khalatpour and his colleagues' solution to this problem exploits a peculiarity of the tiny laser's design. A quantum cascade laser consists of a long rectangular ridge called a waveguide. In the waveguide, materials are arranged so that the application of an electric field induces an electromagnetic wave along the length of the waveguide.

This wave, however, is what's called a "standing wave." If an electromagnetic wave can be thought of as a regular up-and-down squiggle, then the wave reflects back and forth in the waveguide in such a way that the crests and troughs of the reflections perfectly coincide with those of the waves moving in the opposite direction. A standing wave is essentially inert and will not radiate out of the waveguide.

So Hu's group cuts regularly spaced slits into the waveguide, which allow terahertz rays to radiate out. "Imagine that you have a pipe, and you make a hole, and the water gets out," Khalatpour says. The slits are spaced so that the waves they emit reinforce each other -- their crests coincide -- only along the axis of the waveguide. At more oblique angles from the waveguide, they cancel each other out.

Breaking symmetry
In the new work, Khalatpour and his coauthors -- Hu, John Reno of Sandia, and Nazir Kherani, a professor of materials science at the University of Toronto -- simply put reflectors behind each of the holes in the waveguide, a step that can be seamlessly incorporated into the manufacturing process that produces the waveguide itself.

The reflectors are wider than the waveguide, and they're spaced so that the radiation they reflect will reinforce the terahertz wave in one direction but cancel it out in the other. Some of the terahertz wave that lies outside the waveguide still makes it around the reflectors, but 80 percent of the energy that would have exited the waveguide in the wrong direction is now redirected the other way.

"They have a particular type of terahertz quantum cascade laser, known as a third-order distributed-feedback laser, and this right now is one of the best ways of generating a high-quality output beam, which you need to be able to use the power that you're generating, in combination with a single frequency of laser operation, which is also desirable for spectroscopy," says Ben Williams, an associate professor of electrical and computer engineering at the University of California at Los Angeles. "This has been one of the most useful and popular ways to do this for maybe the past five, six years. But one of the problems is that in all the previous structures that either Qing's group or other groups have done, the energy from the laser is going out in two directions, both the forward direction and the backward direction."

"It's very difficult to generate this terahertz power, and then once you do, you're throwing away half of it, so that's not very good," Williams says. "They've come up with a very elegant scheme to essentially force much more of the power to go in the forward direction. And it still has a good, high-quality beam, so it really opens the door to much more complicated antenna engineering to enhance the performance of these lasers."

The new work was funded by NASA, the National Science Foundation, and the U.S. Department of Energy.

Published September 2017

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