1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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These archive pages are provided in order to make it easier for you to find items that you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is to use the "Search RF Cafe" box at the top of every page.
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While all RF Cafe crosswords do in fact use only my hand-entered dictionary of terms and clues (literally thousands accumulated over the years) that pertain exclusively to science, engineering, chemistry, physics, mathematics, astronomy, etc., the choice for a particular title is to help attract search engines to the page. There is nothing deceptive going on, just an attempt to exploit the nature of search engine algorithms that rank pages based on meta tags coinciding with relevant keywords and phrases occurring on the page. Enjoy ...
"Scientists have looked for different ways to force hydrogen into a metallic state for decades. A metallic state of hydrogen is a holy grail for materials science because it could be used for superconductors, materials that have no resistance to the flow of electrons, which increases electricity transfer efficiency many times over. For the first time researchers, led by Carnegie's Viktor Struzhkin, have experimentally produced a new class of materials blending hydrogen ..."
Since I don't watch TV, I was unaware of a Canadian police detective series titled "Murdoch Mysteries," which is cast in Toronto at the turn of the 20th century. Melanie found a DVD at the library with season 1 episodes, and noted that the first show was "Power," with a storyline based on the debate over whether Thomas Edison's DC current was safer than Nikola Tesla's AC current (Tesla was backed by George Westinghouse). You might be familiar with the heated and often violent exchanges that really happened between the two camps, often referred to as "The War of Currents." After all, a lot of money ...
The HFS-12000-XA is a 7,000 to 12,000 MHz surface-mount frequency synthesizer designed as a high performance down-converter LO for RADAR Digital Signal Processors. The design also features low phase noise (<-90 dBc/Hz @ 100 KHz offset) and fast switching capability (<750 μSec, Band-Edge to Band-Edge) critical for signals intelligence applications. The HFS-12000-XA also locks to a 100 MHz reference and contains a channel step size of 1 MHz or ...
"Researchers have been working on a number of alternative chemistries to lithium-ion for next-generation batteries, silicon-air among them. However, while the technology has been viewed as promising and cost-effective, to date researchers haven’t managed to develop a battery of this chemistry with a viable running time. That's until now, with the invention by researchers in Germany of a silicon-air battery that can run more than ..."
Wendy Pearson, writing for IMS ExpertServices, offers this first installment in a series of articles advising people new to the expert witness realm on how to prepare for the process. Being an authority in your professed field is not always to enough assure success in the courtroom - or even for making it as far as a courtroom. Part 1 provides a basic introduction to legal lingo. Just as a person who does not speak the language of a country he/she is visiting is in many ways easy prey for crafty operators, a witness at trial can have his/her credibility damaged by being made to appear ignorant of standard courtroom procedures and language. Accordingly, competent counsel ...
"Researchers have nearly doubled the continuous output power of a type of laser, called a terahertz quantum cascade laser, with potential applications in medical imaging, airport security and more. Increasing the continuous output power of these lasers is an important step toward increasing the range of practical applications. The researchers report their results in the journal AIP Advances, from AIP Publishing. Terahertz radiation sits between microwaves and infrared light on the electromagnetic ..."
Here is a very in-depth and comprehensive discussion on antenna system design and evaluation for a mobile platform; i.e., a car or truck. As was common with QST articles of yore, there is a plethora of equations, sketches, graphs, and tables provided for reference. Radiation resistance, ground resistance, system impedance, antenna tuning, radiation efficiency, current distributions, and much more are introduced and explained. Even being six decades old, the information is as valuable today as it was then ...
"Gallium nitride (GaN) is capturing market share in high-power RF semiconductors, especially in wireless infrastructure, the market research firm said. 'GaN is increasing its market share in 2016, and we believe it will be a significant force by 2021,' said Lance Wilson, research director at ABI Research, in a statement. 'This now mainstream technology bridges the gap between two older technologies, exhibiting the high-frequency performance of Gallium Arsenide and power handling capabilities of Silicon LDMOS ..."
"Smaller and faster has been the trend for electronic devices since the inception of the computer chip, but flat transistors have gotten about as small as physically possible. For researchers pushing for even faster speeds and higher performance, the only way to go is up. University of Illinois researchers have developed a way to etch very tall, narrow finFETs, a type of transistor that forms a tall semiconductor 'fin' for the current to travel over. The etching technique ..."
"Flying drones might sound like a fun hobby, but some RF engineers are making it part of their job, going so far as to envision flying COWs, or Cells on Wings, to provide LTE coverage at concerts or during emergencies. Earlier this month, AT&T announced the launch of a national trial involving drones in a program being overseen by Art Pregler, who serves as AT&T's drone program director and began his tech career in the U.S. Air Force. More trials are continuing, including this week. AT&T started its LTE drone program investigation a year ..."
vidaRF has introduced a line of 4.1/9.5 series connectors and cable assemblies that are designed to address increasing demands in mobile communication industry, including increased performance demands, low PIM, Albaloy plating, and at same time reducing its size to support ongoing space reduction requirements. They feature a smaller footprint than the 7/16 connector (30% less) with similar RF performance ...
My career involving controlled movement of electrons began with working around high voltages and currents. In electrical vocational classes, the instructor lectured on the potential (pun intended) harm that could be done to life and property because of ignorance or inattention to the job at hand. Safety practices were reviewed prior to allowing us plebes to handle not just 3-Ø, 480 V supplies for motors, but also for household AC circuits and low voltage sources with high current outputs. We all had the opportunity to get 'lit up' with 115Vac and even 230 Vac if we dared (a practice that would never be allowed in today's environment). We watched films ...
"The old rules don't necessarily apply when building electronic components out of two-dimensional materials, according to scientists at Rice University. The Rice lab of theoretical physicist Boris Yakobson analyzed hybrids that put 2-D materials like graphene and boron nitride side by side to see what happens at the border. They found that the electronic characteristics of such 'co-planar' hybrids differ from bulkier components. Their results appear this month in the American Chemical Society journal Nano Letters. Shrinking electronics means shrinking their components. Academic labs ..."
"What progress individuals could make, and what progress the world would make, if thinking were given proper consideration! It seems to me that not one man in a thousand appreciates what can be accomplished by training the mind to think." -- Thomas Edison during an interview with B.C. Forbes in The American Magazine, January 1921.
"Companies around the globe are launching an increasing number of satellites, crowding Earth's orbit in an effort to satisfy the ravenous on-demand desire for more broadband, satellite television and communications. In the past five years, the number of operational satellites has jumped 40%, and nearly 1,400 now orbit the Earth. Industry officials say that number could more than double in five years as a revolution in technology has made satellites smaller and more affordable. Entrepreneurs eye the ethereal real estate a couple of hundred miles up as a potentially ..."
e2v is looking for an RF Test / Product Engineer that will support high performance RF IC products and Broad Band Data Converters. This position will develop the test programs, analyse and optimize RF device types such as 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 ...
When this May 1949 issue of Radio & Television News was being written, Messrs. Bardeen. Shockley, and Brattain had recently announced to the world their invention of the point contact germanium transistor. Sylvania Electric here is touting a miniature pocket radio featuring their line of subminiature (aka "peanut") tubes. Tubes like the 1AC5 'only' needed about 60 volts for operation as opposed to 300 volts or more for standard tubes. This required a voltage multiplier circuit that consisted of inductors, diodes, and capacitors for implementation, which added significant volume to the radio. It was in the Autumn of 1954 that Regency began selling its TR-1 transistor radio - the world's first.
"As the Pentagon seeks to cram more electronic gear and wireless devices into a shrinking amount of radio spectrum, its research arm announced guidelines this week for yet another technology competition designed to find new ways to share and ensure access to the airwaves. The Defense Advanced Research Projects Agency announced a Spectrum Collaboration Challenge in March designed to leverage emerging machine-learning tools ..."
A few years ago, I wrote an article titled "Too Clever by Half?," which presented a few magazine advertisements that IMHO were, based on the choice of graphics, either very effective or a total failure. This Koaxis ad appeared in the July 2016 issue of Microwaves & RF magazine. Whether intentional or not, the bald guy lineup is eye-catching - and therefore effective - as evidenced by motivating me to call attention to it. Put a monocle on the guy 2nd from the left and you'll have Werner Klemperer (Colonel Klink of Hogan's Heroes)! ...
"Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity. While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface. A charge density wave (CDW) is a state of matter where electrons bunch together in a repeating pattern, like a standing wave of surface of water ..."
Good Calculators has large collection of calculators for engineering, finance, logistics, loans, budgets, conversions, sports & health, statistics, mechanics, and other topics. Unfortunately, there do not appear to be any electrical engineering calculators, but if you need to check the health of your retirement fund or to calculate the surface area or volume of a frustum, then it has you covered.
"The Changji-Guquan ultra high voltage DC (UHVDC) link will transmit power from the Xinjiang region in the Northwest, to Anhui province in eastern China, setting a new world record in terms of voltage level, transmission capacity and distance. It will be capable of transporting 12,000 megawatts of electricity - the equivalent of 12 large power plants - and is a 50% increase in transmission capacity compared to the 800 kV UHVDC links currently in operation. Using the higher ..."
LadyBug Technologies means Peak Performance in Power Sensors: 9 kHz to 40 GHz and 80 dB DR. LadyBug manufactures a broad line of First Tier NIST traceable USB power sensors that are compatible with Windows XP, Win 7, 8 & 10; in 32 and 64 bit systems, along with LINUX. Also the only SPI & I2C sensor available. Patented NoZero NoCal feature - Simply connect and measure to receive a high accuracy measurement.
These two electronics-themed comics appeared in a 1952 edition of Radio & Television News magazine. In the early days of television, it was common in comedy skits and in cartoons to have someone on a television show interact, to the viewer's great shock, directly with the viewer or to reach out of the set and do something, as in the first comic here. The Three Stooges show did that in a couple shows. One in particular I remember was when they were doing plumbing in a house and had water coming ...
"A new edition of the European Table of Frequency Allocations in the range 8.3 kHz to 3000 GHz has been released. The table is maintained by the European Conference of Postal and Telecommunications Administrations (CEPT) Working Group Frequency Management. Information collected in the European Common Allocation (ECA) table is intended to reflect the main usage of spectrum within CEPT countries. A fully searchable electronic version of the ECA ..."
"The radiation-hardened electronics industry is in the midst of yet-another major transition -- the second in the last quarter-century -- that once again is likely to re-define the space market, boost new industry players, and shake out some of the old ones. The latest round of disruptive technology in the rad-hard electronics industry involves the emerging market for small satellites (SmallSats) with limited life cycles ..."
Anatech Electronics has introduced 1 new bandpass filter design: a 5590 MHz cavity bandpass filter with "N" connectors, a surface mount 1575.42 MHz / 1189.5 MHz ceramic duplexer , and a 217.5 MHz / 221 MHz cavity duplexer with SMA connectors. Anatech offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz ...
This week's tech-themed crossword puzzle, as is the case every week, contains only words pertaining to science, engineering, amateur radio, physics, mechanics, mathematics, etc. Making a special appearance is the name of the most recent company to support RF Cafe through advertising. You will see their banner graphical ad appearing in the right page border sometime this week. Opportunities exist for your company to advertise if you are interested ...
"Huge magnetic fields can be created by firing intense, circularly polarized laser pulses at a target, according to calculations by physicists in Italy, Germany and Russia. Their research suggests that the mysterious phenomenon of 'radiation friction' plays a crucial role in generating the field. Measuring such magnetic fields could offer physicists a new way of studying this poorly understood effect, which is believed to play a crucial role in the physics underlying astrophysical objects such ..."
Arthur (Art) Collins, who began his radio career as a Ham, founded Collins Radio in 1933, in Cedar Rapids, Iowa. Just as civil aviation enthusiasts long ago began associating Wichita, Kansas, with Cessna, Lear, Beechcraft, et al, and its airplanes, radio people associate Cedar Rapids with Collins Radio. In fact - and this is a fact - electronics companies like RF Micro Devices (now Qorvo) and Skyworks Solutions set up RFIC design centers there back in the early 1990s in order to exploit the availability of highly talented engineers who worked for Collins ...
"Better lifecycle characteristics than conventional secondary batteries offers a novel energy source from Murata called UMAL. With its extremely slim form factor and superior charge/discharge properties, the UMAL is designed for deployment in maintenance-free applications such as wireless sensor nodes and wearable designs, the vendor says. The UMAL has a nominal voltage of 2.3 VDC, can supply 12 mAh ..."
"The Navy has awarded Rockwell Collins a $31M contract for weapon replaceable assembly repair support of the Aviation Navy/Airborne Radio Communication airborne radios, which provide secure voice, data and imagery. The contract applies to the AN/ARC 210 version Electronics Protection Radio System and also calls for support for the Communications Security System requirements for the Navy and other Defense Department services ..."
"Stop on the sidewalk on a downtown street in any large American city, and take a look around. Check out the utility poles nearby, the metal boxes planted at the street corners, the cameras dangling from awnings and eaves. Urban infrastructure is made up of thousands upon thousands of moving parts, and many of the gizmos that make a city run are designed to do their jobs without attracting too much attention. Now, a mysterious new device may ..."
The advent of selenium rectifiers in the 1940s was a very welcome new option to circuit designers, consumers, and servicemen. Before that, vacuum tubes did the job (with some use of copper oxide rectifiers). Selenium rectifiers have the advantage of ruggedness and reliability over tubes (~85% vs. 60%, respectively). Not requiring a heater voltage eliminates needing to create heat in excess of that dissipated due to the innate inefficiency. Voltage and power handling is adjusted by stacking appropriate layers and adjusting the physical size, respectively. A failed selenium rectifier reportedly often emitted ...
"The U.S. government last week unveiled a multi-million-dollar project to further the development of 5G technologies, including the establishment of four city-sized testbeds for R&D. National Science Foundation (NSF) has pledged to invest US$400 million over seven years to support the government's Advanced Wireless Research Initiative (AWRI) programme, including a spend of $50 million on 5G research platforms. Four of these Platforms for Advanced Wireless Research (PAWR) will be set up under the project, each ..."
"From a customer perspective, there is a demand for this service whether its accurate or not." - Nolan Doesken, Colorado State University professor, in response to AccuWeather's new 90-day forecasts (HuffPo article). Have you noticed that a few months ago the AccuWeather online forecast began extending out 90 days? I remember being dubious when they went from the original 2-week forecast to a 30-day forecast. Most of the time, for most locations issuing a forecast more than 4 or 5 days in advance is an exercise in vanity. A scientific organization populated with PhD level climatologists, meteorologists ...
"The U.S. Air Force is looking to expand and upgrade its fleet of air-launched electronic warfare jammers, already in wide use, with a $34.8M contract awarded to Raytheon. The contract calls for Raytheon to upgrade current versions of the Miniature Air Launched Decoy-Jammer, known as MALD-J, improving its flight and EW jamming capabilities. The work is expected to be completed in 24 months. The MALD-J is a fairly small, low-cost weapon that can be launched from fighters, bombers and other ..."