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2.1 GHz (5.6-inch, or 14 cm wavelength) radio waves were an almost totally unexplored realm in 1930, with it and higher frequencies being the domain of theoretical research laboratories. Signals generators capable of producing much more than a few hundred megahertz were rare even in commercial applications. As reported here, centimeter-length electromagnetic waves were "according to the theories of Barkhausen and Kurz, [the] result of purely electronic vibrations, whose frequency was determined only by the operative data of the tube and was not dependent on any internal or external oscillation circuit." A half-wave receiving antenna picked up the transmitted signal with a simple diode detector to enable, after ...
"The median income of electrical and electronics engineers increased 3% in 2014, the largest increase since 2008, according to the IEEE-USA's annual salary survey. The total median pre-tax income of U.S.-based EEs increased to $133,000 last year, up from $129,000 in 2013, according to the responses of IEEE members who responded to the survey that indicated they were employed full time in their primary area of technical expertise. Excluding overtime pay ..."
When you need a solution now, MPT provides the engineering, program management, and technology needed with expertise that meets your price and schedule requirements. They deliver on promises so you remain on schedule and on budget. Digital Receivers - front end with amplification, filtering, down conversion. Phased Arrays - L-Band through Ka-Band. Solid State Power Amplifiers (SSPA). Transmit/Receiver (T/R) Modules. Down Converters - integrated assemblies. Please visit MPT's website today to see what they have to offer.
NASA (and its predecessor NACA), and private and public operators have been monitoring solar events in the optical realm for many decades while attempting to correlate terrestrial phenomena with it. Auroral light displays in the extreme polar regions have long been known to be caused by solar flare and coronal mass ejections (CME). With the advent of radio, the electrical nature of the upper atmosphere became evident when static (AM) and long range propagation affected long range communications. Extreme CME activity eventually was associated with behavior of the electrical power grid; indeed, massive blackouts ...
"For most of us, the times when we go astray are happily forgettable. In Einstein's case, even the mistakes are noteworthy." - Lawrence M. Krauss, in What Einstein Got Wrong, appearing in the September 2015 issue of Scientific American.
e2v is looking for an RF Applications Engineer that will support high performance RF IC products and Broad Band Data Converters. This position will provide application support for RF switches, mixers, PLLs, DSA, and prescalers in challenging environments for defense an space systems. High speed data converters with industry leading performance will also be a key focus. The position will also require the candidate to take the lead role in assessing and understanding Aerospace and Defense Electronics customers' system requirements and provide guidance to the R&D teams to develop successful semiconductor products. This position provides a unique opportunity to support current and new cutting edge technology that supports some of our nation's fundamental defense programs ...
Before there was radio, it really didn't matter much how much electromagnetic energy at any frequency was spewed into the air and into electric wires as long as the amplitude was not great enough to physically damage affected equipment. There was no need for an FCC or unintentional radiation limit regulations. It was not long after radio came along that the presence of electromagnetic interference (EMI) made itself painfully obvious due to its presence on audio as static. Motor brush arcing, electrical atmospheric phenomena (lightning, meteors), switching on and off of circuits, intermittent connections, nearby radio spurious emissions, high voltage transformers, and in this case, neon lighting were among ...
Alliance Test Equipment, located in Webster, Massachusetts, is a leading source of quality used/reconditioned test & measurement equipment. Alliance Test sells used & refurbished test equipment, offering short-and long-term rentals. They also purchase your excess test equipment in large or small lots, and do repair, maintenance and calibration. Alliance Test offers products from many manufacturers available at prices discounted up to 80% off manufacturer list price.
For the sake of avid cruciverbalists amongst us, each week I create a new crossword puzzle that has a theme related to engineering, mathematics, chemistry, physics, and other technical words. You will never be asked the name of a movie star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Enjoy!
"You may be the expert in your field, but if you fail to understand how the rules on admissibility of expert testimony may affect your opinions and testimony, you jeopardize your role as an expert. If the court excludes your testimony, all your hard work is for naught and you lose your opportunity to be the expert in front of the jury." IMS ExpertServices is now offering a new whitepaper, What to Expect When You're an Expert. It is the first in a series of whitepapers and presents strategies on how to conduct your expert witness business with an eye toward the rules on admissibility of expert testimony throughout the litigation process. The information ...
The name Ernst Frederick Werner Alexanderson (1878-1975) might not seem overly familiar to you, but he is credited with designing the first high frequency alternator for transmitting longwave audio modulation over long distances. His device preceded the spark and arc type transmitters that infamously spewed harmonics and noise all over the spectrum and were therefore a great nuisance when broadcast at high power levels. It was a relatively (for the time) narrowband scheme that permitted more stations to be co-located in a given service area. He went on the develop one of the first successful television projectors as well. Read a short biography on Mr. Alexanderson in the "Men Who ...
Scientists from the University of Basel in Switzerland have demonstrated for the first time how electrons are transported from a superconductor through a quantum dot into a metal with normal conductivity. This transport process through a quantum dot had already been calculated theoretically in the nineties, but scientists at the University of Basel have now succeeded in proving the theory with measurements. Transport properties such as electrical conductivity play ...
It looks like again in 2016 Melanie and I will be without health insurance because of the prohibitive cost of the misnamed Affordable Care Act (aka Obamacare). Not only will we have no insurance, but we will be taxed at a rate of 2.5% of our Modified Adjusted Gross Income (MAGI*) for opting out. Our expected MAGI of about $60,000 amounts to $1,500 being added to our standard income tax - which already includes paying the full amount of the Social Security tax**. What follows is a brief synopsis of our decision-making rationale. Bear in mind while reading that tens of thousands of Americans are making similar decisions nowadays. Prior to 2014, we had ...
Just in time for holidays for the Nixie tube aficionado who appreciates a fine wooden chassis and 'authentic' vintage, heretofore unused Nixies is Nuvitron's Vintage Nixie Clock (clever name). Says them, "With brand new, unused Nixie tubes that were rescued from exile in long abandoned basements in Eastern Europe, the vintage Nixie tube clock imparts a warm glow from within its beautiful, handmade, Art Deco enclosure. Each clock casing takes over 30 hours to create and a lifetime to admire. Make yourself appear cooler than you actually are with this super cool Nixie tube clock." Now, if anyone is still trying to figure out what to get me for Christmas ... (hat tip to Electronics Weekly, where I learned of it)
Pasternack, a leading provider of RF, microwave and millimeter wave products, adds new millimeter wave (mm-wave) waveguide frequency mixers available in six down-conversion and six up-conversion models that cover full Ka, Q, U, V, E, and W bands. Designs utilize high performance GaAs Schottky Barrier Beam Lead Diodes in balanced configurations that require a +13 dBm LO drive and display low levels of conversion loss ...
Thanks to everyone for the explosive growth of RF Cafe's visitor and page view number in the last year! In 2015 the number of website Visits has grown by about 10%, while the number of Page Views has grown about 300%. That means visitors like you are now spending more time looking at multiple pages once you arrive here. RF Cafe has more than 10,000 unique pages covering a wide variety of engineering and science topics, most of which can be useful to all levels of hobbyists, technicians, students, engineers, managers, and even people with a casual interest in science. I always welcome your comments, suggestions, and contributions. The RF Cafe Forum is available if you prefer that venue for participation (registration not required).
Anatech has released three new RF / microwave filter designs: a 902-928 MHz connectorized cavity bandpass filter model, an 880-915 / 925-960 MHz cavity duplexer model for outdoor applications, and also a 910-920 MHz connectorized cavity bandpass model. All can be ordered directly through their AMCrf web store.