Bell Labs Journal Now Online

“Innovation” is a word often thrown around these days. Back in the old days, you couldn’t find an organization more innovative than Bell Labs. They could certainly afford it, though. They had a monopoly on the telephone system!

At any rate, all of the issues of the Bell Labs Journal from 1922 to 1983 are now online. Within the pages of these journals you’ll find papers on:

  • the invention of the transistor in 1947 and subsequent advances in related solid-state device and circuit technology.
  • Shannon’s paper, “A Mathematical Theory of Communication,” that was published over 60 years ago and gave birth to Information Theory.
  • the charge-coupled device (CCD), a technology that transforms patterns of light into useful digital information, is the basis for many forms of modern digital imaging.
  • cellular telephone service, the concept that multiple lower-power transmitters could be spread throughout a region employing automatic call handoff and frequency reuse that changed the face of communications.

Overall, it’s pretty cool stuff.

NIST Researchers May Have Figured Out New Way to Generate Microwaves

The following is from a NIST press release…….Dan

Researchers at the National Institute of Standards and Technology (NIST) have found theoretical evidence of a new way to generate the high-frequency waves used in modern communication devices such as cell phones. Their analysis, if supported by experimental evidence, could contribute to a new generation of wireless technology that would be more secure and resistant to interference than conventional devices.

The team’s findings point toward an oscillator that would harness the spin of electrons to generate microwaves—electromagnetic waves in the frequencies used by mobile devices. Electron spin is a fundamental property, in addition to basic electrical charge, that can be used in electronic circuits. The discovery adds another potential effect to the list of spin’s capabilities.

The team’s work—a novel variation on several types of previously proposed experimental oscillators—predicts that a special type of stationary wave called a “soliton” can be created in a layer of a multilayered magnetic sandwich. Solitons are shape-preserving waves that have been seen in a variety of media. (They first were observed in a boat canal in 1834 and now are used in optical fiber communications.) Creating the soliton requires that one of the sandwich layers be magnetized perpendicular to the plane of the sandwiched layers; then an electric current is forced through a small channel in the sandwich. Once the soliton is established, the magnetic orientation oscillates at more than a billion times a second.

“That’s the frequency of microwaves,” says NIST physicist Thomas Silva. “You might use this effect to create an oscillator in cell phones that would use less energy than those in use today. And the military could use them in secure communications as well. In theory, you could change the frequency of these devices quite rapidly, making the signals very hard for enemies to intercept or jam.”

Silva adds that the oscillator is predicted to be very stable—its frequency remaining constant even with variations in current—a distinct practical advantage, as it would reduce unwanted noise in the system. It also appears to create an output signal that would be both steady and strong.

The team’s prediction also has value for fundamental research.

“All we’ve done at this point is the mathematics, but the equations predict these effects will occur in devices that we think we can realize,” Silva says, pointing out that the research was inspired by materials that already exist. “We’d like to start looking for experimental evidence that these localized excitations occur, not least because solitons in other materials are hard to generate. If they occur in these devices as our predictions indicate, we might have found a relatively easy way to explore their properties.”


M.A. Hoefer, T.J. Silva and M.W. Keller. Theory for a dissipative droplet soliton excited by a spin torque nanocontact. Physical Review B, 82, 054432 (2010), Aug. 30. 2010. DOI: 10.1103/PhysRevB.82.054432

First Article on Transistors?

Google recently digitized all of the back issues of Popular Science. In the September 1948 issue, they ran an article on the new electronic device the transistor. This could be the first article in a commercial publication on the transistor.

Here are a couple of quotes:

  • “The device that may start a revolution in electronics is smaller than a paper match.”
  • “Whether transistors will ever replace the vacuum tubes in your home radio will probably depend most on how much it costs to make them.

Now, of course, transistors are on the order of microns, and in integrated circuits cost a small fraction of a penny. And all this happened in about sixty years.

Paintable Electronics? NIST Studies Spray-On Manufacturing of Transistors

From the 3/30/10 issue of NIST Tech Beat:

A multidisciplinary research team at the National Institute of Standards and Technology (NIST) has found* that an organic semiconductor may be a viable candidate for creating large-area electronics, such as solar cells and displays that can be sprayed onto a surface as easily as paint.

While the electronics will not be ready for market anytime soon, the research team says the material they studied could overcome one of the main cost hurdles blocking the large-scale manufacture of organic thin-film transistors, the development of which also could lead to a host of devices inexpensive enough to be disposable.

This airbrush technique deposits a well-studied material called P3HT to create spray-on transistors, which perform comparably to lab-standard equivalents made by spin coating.

Silicon is the iconic material of the electronics industry, the basic material for most microprocessors and memory chips. Silicon has proved highly successful as a substance because billions of computer elements can be crammed into a tiny area, and the manufacturing process behind these high-performance chips is well-established.

But the electronics industry for a long time has been pursuing novel organic materials to create semiconductor products—materials that perhaps could not be packed as densely as state-of-the-art silicon chips, but that would require less power, cost less and do things silicon devices cannot: bend and fold, for example. Proponents predict that organic semiconductors, once perfected, might permit the construction of low-cost solar cells and video displays that could be sprayed onto a surface just as paint is.

“At this stage, there is no established best material or manufacturing process for creating low-cost, large-area electronics,” says Calvin Chan, an electrical engineer at NIST. “What our team has done is to translate a classic material deposition method, spray painting, to a way of manufacturing cheap electronic devices.”

The team’s work showed that a commonly used organic transistor material, poly(3-hexylthiophene), or P3HT, works well as a spray-on transistor material because, like beauty, transistors aren’t very deep. When sprayed onto a flat surface, inhomogeneities give the P3HT film a rough and uneven top surface that causes problems in other applications. But because the transistor effects occur along its lower surface—where it contacts the substrate—it functions quite well.

Chan says the simplicity of spray-on electronics gives it a potential cost advantage over other manufacturing processes for organic electronics. Other candidate processes, he says, require costly equipment to function or are simply not suitable for use in high-volume manufacturing.

* C.K. Chan, L.J. Richter, B.Dinardo, C.Jaye, B.R. Conrad, H.W. Ro, D. S. Germack, D.A. Fischer, D.M. DeLongchamp, D. J. Gundlach. High performance airbrushed organic thin film transistors. Applied Physics Letters, 96, 133304. March 30, 2010. doi:10.1063/1.3360230

Simple Antenna Demos Antenna Polarization

I’m always amazed when things actually work. So you can imagine my amazement when I actually got the demo shown in the Make: Magazine video below to work.

Diana, KC2UHB, used her lightbulb/antenna combo to demonstrate the principle of directional antennas by using a Yagi as her transmitting antenna. I didn’t have a Yagi handy, so I used one of my home-made J-pole antennas.

Because the J-pole isn’t directional, I obviously couldn’t use it to demonstrate directionality, but it worked quite nicely to demonstrate the principle of polarization. All I had to do was to position the receiving antenna so that it was parallel to the J-pole and the light was nice and bright. Then, I rotated the antenna until it was perpendicular to the J-pole. The light got dimmer and dimmer until eventually you couldn’t see it emitting any light at all. Rotate it back to perpendicular and the bulb burned brightly again.

I think I’ll try to make a video of this down at the Museum this Saturday.

The Transistor Museum Dedicated to Preserving the History of Semiconductors

The Transistor Museum’s tagline is “Dedicated to Preserving the History of the Greatest Invention of the 20th Century,” and it does a pretty good job of it. On this website you’ll find articles on:

  • The First Germanium Hobbyist Transistors
  • Early Transistors at Motorola
  • The First Transistor in Space
  • Norman Krim, the Father of the CK722 Transistor
  • a whole lot more

Like all good museums, they also have a museum store. They sell a couple of books on the early semiconductors as well as some of those transistors themselves. They’re kind of pricey, though. A 2N60 or 2N609, for example, costs $20.

Ferrite Beads are an Elegant Solution

Here’s a cute article on the use of ferrite beads written by a couple of engineers at Intersil. Some interesting stuff about why ferrite inductors work so well.

What the Heck is Phase Noise, Anyway?

Hams sometimes bandy about the term “phase noise,” but few hams really understand it. Most of us can figure out that less phase noise is better than more phase noise, but that’s about as far as our knowledge goes.

To help you understand the concepts, there is a paper about phase noise on www.rfic.co.uk. While there is a lot of complicated, engineering math in the paper (this is complicated stuff, after all), the first two pages offer a simple explanation of the basic concepts. In explaining how phase noise affects a system, the paper notes:

In transmitters local oscillator noise is amplified by the subsequent amplifier stages and is eventually fed to the antenna together with the wanted signal. The wanted signal is therefore surrounded by a band of noise originating from the phase noise of the local oscillator. Therefore the noise generated can spread over several kHz masking nearby lower power stations as shown in figure 3 (shown below).

To relate this to a common example in ham radio, this is why you want rigs with low phase noise at your Field Day operation. Rigs that have poor phase noise performance will seriously raise the noise floor, affecting all of the other radios, especially those attempting to operate on the same band. For example, a 40m phone station running a rig with relatively high phase noise might swamp a station running 40m CW.

Make: Tackles Learning Electronics

The publishers of Make: magazine have just come out with a book on the basics of electronics. You can download a sample of the book that include the table of contents, the index, and Chapter 1.

From what I could see I like it. Right off the bat, they have you build a little LED circuit consisting of a battery, potentiometer, and LED. With just those three components, they’re able to demonstrate the concepts of voltage, resistance and current, as well as teach you how to use a multimeter.

Read more

New Spectrum Allocation Chart

No ham shack should be without a spectrum allocation chart. Now, Tektronix, the oscilloscope maker, is now offering a new one. Here’s what their website has to say:

New Worldwide Spectrum Allocations Poster Request Form

Thanks your interest in our NEW poster. It provides a color-coded view of the worldwide spectrum allocations for all ITU (International Telecommunications Union) regions. It’s the only graphical poster that shows the international spectrum allocations in an easy-to-find format.

There’s a form to fill out, so that they can get your address, and the poster will be winging its way to you.