Special Coverage

Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines
Vibration Tables Shake Up Aerospace and Car Testing
Supercomputer Cooling System Uses Refrigerant to Replace Water

Interview with John Dunec, Branch Manager of COMSOL, Inc.

In this podcast John Dunec, Branch Manager of COMSOL, Inc., discusses how the breakthrough of multiphysics modeling techniques is making waves in the electronics industry. Applications cover everything from modeling p-n junctions in semiconductors and joule heating in circuits to forced convective cooling of circuit boards.

Based on the April 9, 2008 webcast sponsored by COMSOL, this free podcast introduces you to applying multiphysics modeling techniques to electronic analysis and guides you through several examples including electro-thermal stress analysis in a surface coil, simulating a high-frequency RF inductor, and thermal effects on cross-talk between bond wires.

Posted in: Podcasts

Interview with Ray Alderman, Executive Director of VITA

Founded in 1984 to promote VMEbus technology, VITA is a non-profit organization of more than 125 vendor companies who share a common interest in real-time, modular embedded computing systems. In August 2008, VITA's Executive Director, Ray Alderman, agreed to speak with Embedded Technology's editor, Bruce Bennett, about the state of VME technology in 2008, how far it has come in its 30-year history, and where it is likely to go in the future.

Posted in: Podcasts

Directed Growth of Carbon Nanotubes Across Gaps

Single-walled carbon nanotubes grow aligned along applied electric fields.

An experiment has shown that when single- walled carbon nanotubes (SWNTs) are grown by chemical vapor deposition in the presence of an electric field of suitable strength, the nanotubes become aligned along the electric field. In an important class of contemplated applications, one would exploit this finding in fabricating nanotube transistors; one would grow SWNTs across gaps between electrodes that would serve, subsequently, as source and drain contacts during operation of the transistors.

Posted in: Briefs, TSP, Materials, Transistors, Transistors, Fabrication, Chemicals, Nanomaterials

Nanotip Carpets as Antireflection Surfaces

Reflectance less than 10–3 is readily achieved.

Carpetlike random arrays of metal-coated silicon nanotips have been shown to be effective as antireflection surfaces. Now undergoing development for incorporation into Sun sensors that would provide guidance for robotic exploratory vehicles on Mars, nanotip carpets of this type could also have many uses on Earth as antireflection surfaces in instruments that handle or detect ultraviolet, visible, or infrared light.

Posted in: Briefs, TSP, Materials, Optics, Optics, Materials properties, Nanomaterials

Nano-Engineered Catalysts for Direct Methanol Fuel Cells

Small particle sizes and large surface areas can be produced economically and consistently.

Nano-engineered catalysts, and a method of fabricating them, have been developed in a continuing effort to improve the performances of direct methanol fuel cells as candidate power sources to supplant primary and secondary batteries in a variety of portable electronic products. In order to realize the potential for high energy densities (as much as 1.5 W•h/g) of direct methanol fuel cells, it will be necessary to optimize the chemical compositions and geometric configurations of catalyst layers and electrode structures. High performance can be achieved when catalyst particles and electrode structures have the necessary small feature sizes (typically of the order of nanometers), large surface areas, optimal metal compositions, high porosity, and hydrophobicity.

Posted in: Briefs, TSP, Materials, Catalysts, Fuel cells, Methanol, Fabrication, Nanotechnology

Capillography of Mats of Nanofibers

These mats can be the basis of small devices and instruments.

Capillography (from the Latin capillus, “hair”, and the Greek graphein, “to write”) is a recently conceived technique for forming mats of nanofibers into useful patterns. The concept was inspired by experiments on carpetlike mats of multiwalled carbon nanotubes. Capillography may have the potential to be a less-expensive, less- time-consuming alternative to electron- beam lithography as a means of nanoscale patterning for the fabrication of small devices and instruments.

Posted in: Briefs, TSP, Manufacturing & Prototyping, Fabrication, Fibers, Nanomaterials

HEMT Amplifiers and Equipment for Their On-Wafer Testing

Power levels in CPW circuits can be measured without packaging.

Power amplifiers comprising InP-based high-electron-mobility transistors (HEMTs) in coplanar-waveguide (CPW) circuits designed for operation at frequencies of hundreds of gigahertz, and a test set for on-wafer measurement of their power levels have been developed. These amplifiers utilize an advanced 35-nm HEMT monolithic microwave integrated-circuit (MMIC) technology and have potential utility as local- oscillator drivers and power sources in future submillimeter-wavelength heterodyne receivers and imaging systems. The test set can reduce development time by enabling rapid output power characterization, not only of these and similar amplifiers, but also of other coplanar-waveguide power circuits, without the necessity of packaging the circuits.

Posted in: Briefs, Semiconductors & ICs, Amplifiers, Integrated circuits, Amplifiers, Integrated circuits, Test procedures

On-Wafer Measurement of a Silicon-Based CMOS VCO at 324 GHz

Compact, low-power, electronically tunable submillimeter-wave local oscillators are now feasible.

The world’s first silicon- based complementary metal oxide/semi- conductor (CMOS) integrated-circuit voltage-controlled oscillator (VCO) operating in a frequency range around 324 GHz has been built and tested. Concomitantly, equipment for measuring the performance of this oscillator has been built and tested. These accomplishments are intermediate steps in a continuing effort to develop low-power- consumption, low-phase-noise, electronically tunable signal generators as local oscillators for heterodyne receivers in submillimeter-wavelength (frequency > 300 GHz) scientific instruments and imaging systems. Submillimeter-wavelength imaging systems are of special interest for military and law-enforcement use because they could, potentially, be used to detect weapons hidden behind clothing and other opaque dielectric materials. In comparison with prior submillimeter-wavelength signal generators, CMOS VCOs offer significant potential advantages, including great reductions in power consumption, mass, size, and complexity. In addition, there is potential for on-chip integration of CMOS VCOs with other CMOS integrated circuitry, including phase-lock loops, analog-to-digital converters, and advanced microprocessors.

Posted in: Briefs, TSP, Semiconductors & ICs, Amplifiers, Imaging, Imaging and visualization, Integrated circuits, Semiconductor devices, Amplifiers, Imaging, Imaging and visualization, Integrated circuits, Semiconductor devices, Silicon alloys

High-Voltage, Asymmetric-Waveform Generator

This circuit would be optimized for a capacitive load.

The shapes of waveforms generated by commercially available analytical separation devices, such as some types of mass spectrometers and differential mobility spectrometers are, in general, inadequate and result in resolution degradation in output spectra. A waveform generator was designed that would be able to circumvent these shortcomings. It is capable of generating an asymmetric waveform, having a peak amplitude as large as 2 kV and frequency of several megahertz, which can be applied to a capacitive load. In the original intended application, the capacitive load would consist of the drift plates in a differential-mobility spectrometer. The main advantage to be gained by developing the proposed generator is that the shape of the waveform is made nearly optimum for various analytical devices requiring asymmetric-waveform such as differential-mobility spectrometers. In addition, this waveform generator could easily be adjusted to modify the waveform in accordance with changed operational requirements for differential-mobility spectrometers.

Posted in: Briefs, TSP, Electronics & Computers, Capacitors, High voltage systems, Spectroscopy, Switches, Capacitors, High voltage systems, Spectroscopy, Switches, Test equipment and instrumentation

Group-III Nitride Field Emitters

Growing group-III nitride films spontaneously split into columns.

Field-emission devices (cold cathodes) having low electron affinities can be fabricated through lattice- mismatched epitaxial growth of nitrides of elements from group III of the periodic table. Field emission of electrons from solid surfaces is typically utilized in vacuum microelectronic devices, including some display devices. The present field-emission devices and the method of fabricating them were developed to satisfy needs to reduce the cost of fabricating field emitters, make them compatible with established techniques for deposition of and on silicon, and enable monolithic integration of field emitters with silicon-based driving circuitry.

Posted in: Briefs, Electronics & Computers, Electronic equipment, Electronic equipment, Displays, Displays, Fabrication

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