RF Cafe Software
About RF Cafe
1996 - 2022
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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National Advertisement: World's 1st AC Power Strip?
Could this be the world's first publically documented produced rack-mounted AC power strip? The National Company of Cambridge, Massachusetts, which began life as the National Toy Company, ran a long series of advertisements in QST and other electronics magazines that were heavy on text and light on pictures - definitely not the norm in advertising. This one, number 62, from a 1939 issue describes, along with a reference frequency oscillator, how their engineering team fabricated what we now call an AC power strip for use in an equipment rack. According to the sketch provided, there does not appear to be an On/Off switch and almost certainly not any form of surge protection as is common (maybe even required by UL) for modern power strips ...
NASA, FAA Demonstrate Wireless Communication w/Aircraft
My first thought when seeing this headline was, 'as opposed to wired communications with the aircraft?' The story is referring to en route traffic and weather data that requires a high-speed communications link heretofore not available to high speed aircraft. "For the first time ever, a team of engineers at NASA's Glenn Research Center conveyed aviation data - including route options and weather information - to an airplane over a wireless communication system for aircraft on the ground. The demonstration, which was conducted at Glenn's Communications, Navigation and Surveillance ..."
Lampen & Röhren (Lamps & Tubes) Online Museum
If you like pictures of sehr cool-looking devices involving vacuum-filled (an oxymoron?) glass enclosures, i.e., lamps and tubes, then you will want to spend a few minutes perusing the personal collection of Giorgio Basile, of Nivelles, Belgium. Per the homepage of his Lamps & Tubes website: "My collection consists of more than 3,500 lamps and vacuum tubes. This is a wide area! In addition to well known incandescent lamps, radio tubes and cathode ray tubes, it includes, among others: arc lamps, light sources for the laboratory, transmitting tubes, camera tubes, flash lamps, microwave tubes, photocells, photomultipliers, radiation detectors, rectifiers, relays, thyratrons ..."
Silicon Nanoparticles a Boon for Fiber Optic Telecomms
"An international team of researchers from the Moscow Institute of Physics and Technology (MIPT), ITMO University (St Petersburg), and the Australian National University have demonstrated that silicon nanoparticles can significantly increase the intensity of the Raman effect. The results could be a boon to nanoscale light emitters and nanoscale amplifiers used in fiber optic telecommunications. In the Raman scattering effect, light interacts with certain materials to produce longer or shorter wavelengths, or different colors ..."
Notable Tech Quote: Sherry Hess
"When I am asked what I do for a living, I say 'my company makes the products that allow you to use all the wireless gadgets you love.'" - Sherry Hess, VP of Marketing, National Instruments, AWR Group, in an interview with Chris DeMartino of Microwaves & RF magazine. For nearly a decade, Sherry has been championing the extensive NI AWR Design Environment™ software product portfolio of high-frequency design environments consisting of System simulation (Visual System Simulator™), Circuit simulation (Microwave Office and Analog Office), and Electromagnetic analysis (AXIEM and Analyst™).
Superconducting Quantum-Dot Turnstile Singles out Electrons
"A metallic quantum dot sandwiched between two superconductors – which functions as an electronic turnstile, only permitting one electron through at a time – has been developed by researchers in France, Russia and Finland. By driving an AC voltage through the device, the researchers can control the tunneling of electrons into and out of the dot. While such turnstiles have been made before, this is the first where electrons at only one quantum energy level are allowed to pass through. This, say the researchers, makes the device ideal for quantum-metrology applications. The ability to control the flow of current ..."
Tech News: May 10
"Urgent!! Ericsson Transmission Engineer--- Asian Prefered !!!" (hmm... racism?)
Please Thank Electro Photonics for Supporting RF Cafe!
Electro-Photonics LLC is a global supplier of RF & Microwave components. Their products include SMT hybrid and directional couplers, wire bondable passive components, and very useful test boards for evaluating components. The Electro-Photonics team can support your small R&D design requirements with RF & microwave test fixtures and save you valuable design and characterization time. • SMT 90° hybrid & directional couplers • evaluation test boards • filters • microwave test fixtures • spiral inductors • alumina transmission lines, and more ...
One Problem in Choosing Test Leads
Authors Cohen and Hessinger warn about the need to consider the capacitive loading effects of shielded and closely-space test leads when measuring other than direct current or very low audio or line frequencies. Lead capacitance is especially likely to affect measured values when the frequency is high and/or the source and load impedances are high. As was common in the day, capacitance units of μμfd (micro-micro farads = 10-6 x 10-6 = 10-12 F) are cited, which is equivalent to units of pF (10-12 F) ...
Professor's Differential Equations Lead to Flight Delay
"An Ivy League professor says he was interrogated and his flight from Philadelphia to Syracuse delayed because another passenger thought his cryptic writings, which turned out to be mathematical equations, were suspicious, the Washington Post reports. Guido Menzio, a 40-year-old professor of economics at the University of Pennsylvania, told the Post that he was doing work related to a talk he would be giving at Queens University in Ontario - Syracuse was a connecting stop on the way to Canada - and the passenger next to him apparently became ..."
Physicists Discover New State of Water Molecule
"Water molecules trapped in tiny channels exist in a blurry quantum superposition of six different configurations that bears little resemblance to the structure of a free molecule. That is the finding of physicists in the U.S. and UK, who have used neutron scattering to map the locations of hydrogen atoms in water molecules trapped in the mineral beryl – revealing that the atoms tunnel between the six configurations. The researchers have also found evidence that, unlike normal water, a trapped molecule has a zero electric-dipole moment ..."
An Amateur Application of the Wien Bridge
Wien bridge oscillators had been around for a few years prior to this article in the January 1941 issue of QST magazine, but evidently they had not been applied widely to amateur radio applications. In fact, Hewlett-Packard's very first product, the Model 200A audio oscillator, employed a Wien bridge oscillator as its frequency determining circuit. U.S. patent 2268872 provides a detailed description of its operation as well as the basic schematic. It was considered breakthrough design because its amplitude and frequency stability rivaled that of the beat frequency oscillators of the day - at a small fraction of the cost, size, and weight. The Model 200A quickly became a staple instrument on the benches of designers and launched HP into the Keysight ...
IEEE Acquires GlobalSpec from IHS
This is pretty big news, released on April 29, 2016: "'IEEE, the world's largest technical professional organization dedicated to advancing technology for humanity, today announced the acquisition of GlobalSpec, a leading source of news, data and analytics for the global engineering and technical community including the widely known brand name Engineering360. The new for-profit subsidiary of IEEE has been renamed IEEE GlobalSpec, Inc. and will significantly complement IEEE's already broad offerings for engineers as well as its emerging position in research analytics, further fueling the organization's value to industry ..."
Watch Mercury Sail Across the Sun
"On Monday, you can watch Mercury sail across the sun. It’s an astronomical event known as the Mercury transit, and it occurs about a dozen times a century. During the trip, the planet will appear as a black speck awash in the sun’s light. You can track its celestial silhouette for about seven hours, starting around 7:12 a.m. Eastern and ending around 2:42 p.m. Depending on the weather, it should be visible from most parts of the world, except for Australia, New Zealand and parts of East Asia. The best way to view it is through a telescope or on several live streams, but don't try to sneak a peak with your ..."
Tech News: May 9
Cupertino's Mayor Urges Apple to Pay More Tax ("pioneer in corporate tax avoidance")
Thanks to Centric RF for Continued Support!
Centric RF is a company offering from stock various RF and Microwave coaxial components, including attenuators, adapters, cable assemblies, terminations, power dividers, and more. We believe in offering high performance parts from stock at a reasonable cost. Their parts operate in the frequency ranges of 0-110 GHz, and at power levels from 0.5-500 watts. Order today, ship today! Centric RF is currently looking for vendors to partner with them. If interested please email expressing an interest to email@example.com
U.S. Navy’s Next-GenComms System Frozen in Italian Courts
After seven years and more than $7B, MUOS is ready to go. There's just one problem with its Sicily station. Where there was once a cork forest, there is now just barren land. Nothing grows behind the tall fences that mark the 410-acre perimeter around the U.S. Navy area in Niscemi, Sicily. Behind the fences, atop the only hill, three huge satellite dishes dominate the panorama, standing 60 feet wide and as tall as a 10-story building. This is 1/4 of the most sophisticated military communication system ...
Skyworks 75 Ω Switches for Set-top Box and CATV
Skyworks is pleased to introduce two new SPDT 75 Ohm switches that are ideal for set-top box and DVR applications. The SKY13547-490LF and SKY13548-385LF feature ultra-high linearity and meet the rigorous requirements of DOCSIS 3.0/3.1 applications. They also boast very low insertion loss and high power handling capability. Skyworks' new switches are fully integrated and internally matched, reducing bill of material costs for customers. They are available in compact 1 x 1 x 0.45 and 2 x 2 x 0.55 mm packages, saving precious application board space and cost for OEMs. These devices can also be used for terrestrial and cable set-top box, cable modem and home gateway ...
1-Step Graphene Patterning Method Developed
"Researchers from the University of Illinois at Urbana-Champaign have developed a one-step, facile method to pattern graphene by using stencil mask and oxygen plasma reactive-ion etching, and subsequent polymer-free direct transfer to flexible substrates. Graphene, a two-dimensional carbon allotrope, has received immense scientific and technological interest. Combining exceptional mechanical properties, superior carrier mobility, high thermal conductivity, hydrophobicity, and potentially low manufacturing cost, graphene provides a superior base material for next generation bioelectrical, electromechanical, optoelectronic, and thermal ..."
Honeywell Seeking a Sr. Antenna Test Technician
The Sr. Antenna Test Technician will perform all antenna, material and environmental testing of antennas to meet tasking requirements utilizing a planar near field range, anechoic chamber and environmental test chamber. The Senior Antenna Test Technician will also perform the following: Maintain electronic records library of test result data on completed customer testing tasks. Support engineering tasks related to the repair, fabrication, assembly, production, installation and testing of antennas and electronic hardware and systems. Utilize and interpret schematics, wiring diagrams, test manuals, test procedures and performance specifications to ...
Spying Billboards Track Your Phone as You Walk By
"Anybody who walks or drives past new tracking billboards with a mobile phone in their pocket can be spied on without their knowledge or consent: a potential invasion of privacy that US Senator Charles E. Schumer wants the US Federal Trace Commission (FTC) to investigate. Schumer, a Democrat from New York, delivered a briefing in Times Square on Sunday, electronic billboards blinking and scrolling behind him. These new 'spying' billboards raise serious questions about privacy, Schumer said ..."
Tech News: May 6
FCC Proposes $51 Million in Penalties for Lifeline Program (aka Obamaphones)
Researchers Develop Dissolvable Memristor
"Researchers at two Chinese universities, the Cavendish Laboratory at Cambridge University and the University of Bolton in the UK, have produced a so-called memristor device made from egg proteins, magnesium and tungsten. A memristor – sometimes simply called a non-volatile resistive memory – is a two-contact variable device that not only controls the flow of electrical current, like a resistor, and does so as a function of its previous history, a memory effect and hence the memristor name. Transient electronics and memristors have previously ..."
25 Highest Paying Companies in America for 2016
"According to Glassdoor's latest report revealing the 25 Highest Paying Companies in America for 2016, several companies are offering employees six figure paychecks. This report is based on each company's median total compensation, compiled by looking at salary reports ..." Unfortunately, but not surprisingly, companies likely to employ electrical and RF engineers and technicians are not well-represented.
#1: A.T. Kearney - $167,534
#3: Juniper Networks - $157,000
#5: Google - $153,750
#10 : Cadence EDA - $150,010
#12: Facebook - $150,000
#19: LinkedIn - $145,000
#22: Microsoft - $141,000
#25: Broadcom - $140,000
Crowd-Funding an SDR Platform: Lime Microsystems
"Lime Microsystems has launched a crowd-funding campaign to bring its LimeSDR software defined radio platform into full-scale production. The campaign, hosted on the Crowd Supply platform, aims to raise $500,000 to fund the final stages of development and mass production of the LimeSDR platform. The LimeSDR platform is a low cost application-enabled software defined radio (SDR) platform that can be programmed to support virtually any type of wireless standard – including Wi-Fi, ZigBee and Bluetooth through to cellular standards such as UMTS, LTE and GSM and to the emerging IoT ..."
Mac's Radio Service Shop: A Breathing Spell
We are accustomed these days with stores having "no questions asked" return policies for just about anything. I once watched a guy successfully return a 4" PVC plumbing fitting that had clearly been smeared with glue in the coupling areas. Another time a guy returned a painting drop cloth that was full of paint, declaring that it wasn't what he wanted. The return counter bins of Walmart and other stores are always chock full of stuff. Such was not always the case, though. This episode of Mac's Radio Service Shop, mentions, among other thing, how busy he and sidekick Barney had been right after Christmas doing troubleshooting and repair on various electronic equipment that had been received as gifts. Imagine receiving ...
Introducing the Disposable Laser
"Since lasers were invented more than 50 years ago, they have transformed a diverse swath of technology - from CD players to surgical instruments. Now researchers from France and Hungary have invented a way to print lasers that's so cheap, easy and efficient they believe the core of the laser could be disposed of after each use. The team reports its findings in the Journal of Applied Physics, from AIP Publishing. 'The low-cost and easiness of laser chip fabrication are the most significant aspects of our results,' said Sébastien Sanaur, an associate professor ..."
Z-Communications Intros Fixed Frequency 5,900 MHz PLL
Z-Comm announces a new fixed frequency phase locked loop model RFS5900A-LF in the C-band. The RFS5900A-LF is a fully integrated synthesizer operating at 5900 MHz which is phase locked to a 10 MHz reference with a stability of ±2.5 ppm. This low cost PLL features a typical phase noise of -80 dBc/Hz, -85 dBc/Hz, and -103 dBc/Hz at the 1 kHz, 10 kHz and 100 kHz offsets, respectively. The RFS5900A-LF is designed to deliver an output power of 3۬±2 dBm while operating off a VCO voltage supply of 5Vdc and drawing ...
Military Services Look to Promote 'Intrepreneurs'
"Among the expanding efforts to transform the way the U.S. military develops and deploys new technologies based on models perfected by Silicon Valley entrepreneurs is a new project designed to support what organizers call a cadre of 'military intrapreneurs.' The Athena Project convened last week in Silicon Valley to stage what amounted to a project-pitching session. The idea is to develop new acquisition skills akin to technology startups that would eventually allow the military services ..."
2016 Engineering Education and Research Resources DVD
Keysight is dedicated to meaningful collaboration with educators and researchers at every level around the world. This year's DVD has been updated with almost 200 new items in 7 key focus areas relating to education and research. You will find timely application notes, white papers, case studies, informative videos, and webcasts, as well as additional resources relative to Keysight solutions in these focus areas: • Software Design & Simulation Solutions • Communications Technology • Test & Measurement Science • Nanotechnology & Material Measurement Classroom ...
Building Your Engineering Team: Finding and Retaining Talent
"While there are common elements to building and retaining a team regardless of experience level, there are some unique considerations involved in recruiting and retaining your experienced team members. Here are some tips for recruiting and keeping your high value, senior engineering talent: 1. It's Your First Level Network - An individual's personal network is not a thing that is built overnight. It represents the value of your relationship with people over a period of years ..."
Honeywell Seeking a Sr. RF Engineer
The Sr. RF Engineer will perform as a competent specialist, consultant, and/or advisor on assignments requiring advanced application of technical or engineering principles relative to Radio Frequency Engineering. Assignments are generally complex in nature with considerable discretion given to work details and approaches utilized. Specific responsibilities will include: •Provides support in the design, development, and testing of radio frequency (RF) and/or microwave systems architecture, components, circuits or products. Efforts may include analog and digital circuits or products, frequency synthesizers, amplifiers, transmitters and receivers, down converters, frequency multipliers, digital logic ...
Lockheed Martin's Laser Defense Takes Down Any Missile
"Part of the issues that have held laser defense systems back in the past is the incredible amount of power needed to operate the mechanisms, as well as their operating inefficiencies. In theory, the technology has shown a lot of promise when it comes to defense integration, and it would appear that Lockheed Martin has begin to overcome some of the previously limiting factors in the industry. Lockheed Martin claims to have developed 'innovative fiber lasers, sophisticated beam control and auxiliary technologies,' pushing the boundaries of what laser systems can do. Lasers can ..."
How to Find an Engineering Apprenticeship
"Doing an apprenticeship is a great way of having real-life work experience and getting a feel of what it's like to actually work in the industry. It is also one of the ways to avoid going to university but still getting a career you desire. If this is something you'd be interested in, continue reading! The following are top 10 tips that will help you find an apprenticeship: 1. Research is crucial! Read about all the different areas of engineering you can potentially work in, which companies take more interns in, what skills are necessary, etc. 2. Choose an area you are most interested ..."
Antenna Design Turns Vehicles into Broadcast Equipment
"High-frequency antennas transmit radio waves across vast distances and even over mountain ranges using very little energy, making them ideal for military communications. These devices, however, have one big problem: They need to be huge to operate efficiently. Instead of adding more bulk, University of Wisconsin–Madison engineers are working to increase the effective size of antennas by turning the military vehicles that carry them into transmitters—using the structures that support the antennas themselves to help broadcast signals. Troops in remote locations need to communicate by radio ..."
KR Electronics Intros 8 Channel High Frequency Multiplexer
KR Electronics announces the availability of an 8 Channel High Frequency Multiplexer, part number 3225. The contiguous multiplexer has low input VSWR across the entire band and uses selective elliptic filters for each band. Please contact KR Electronics for details ...
Times Microwave Weatherproofing Kits for RF Connectors
"Times Microwave Systems in Wallingford, Conn., is introducing the IPB weatherproofing kits for RF and microwave connectors in long-term outdoor deployments and mission-critical short term deployments. The IPB boots come in two different interface sizes (N and 7/16 DIN). The 'N' boots will cover anything smaller than a mini DIN. Boots are sized for a particular cable and are available with either male or female threads. Boots are available for LMR-400 and 600 as well as quarter-inch and half-inch helically corrugated cables, and half-inch and 7/8-inch annularly corrugated cables. O-rings are ..."
James Clerk Maxwell on Education
"The aim of an experiment of illustration is to throw light upon some scientific idea so that the student may be able to grasp it. ...The educational value of such experiments is often inversely proportional to the complexity of the apparatus." - James Clerk Maxwell, The Scientific Papers of James Clerk Maxwell - Vol. 2, p243, by W.D. Niven.
Ground Resistance and Its Measurement
An old electrician's saying goes "Ground is ground the world around," implying that every point on Earth's surface is at the same potential - specifically 0 volts. We know, of course, that it is not so. Maybe on average such a claim could be made, but just as 'sea level' is not the same at all points on the ocean's surface (hence we speak of 'mean sea level'), neither is the voltage potential the same everywhere. Further, just as the salinity of all points on the ocean surface do not have the same salinity (and thereby conductivity), the conductivity of various places on dry land vary - often significantly. Electric power systems are very concerned with soil electrical conductivity in the vicinity of power generation installations ...
Honeywell Seeking a Sr. Antenna Test Engineer
The Sr. Antenna Test Engineer shall oversee and manage personnel and resources associated with supporting antenna testing and environmental testing of systems on program. Additional duties shall include: • Act as technical resource regarding testing of antennas on antenna ranges to include far field, spherical and planar near-field systems. • Develops and documents test procedures and schedules associated with conducting antenna and material testing covering a wide frequency spectrum. Analyzes test results and provides formal test reports to customer. • Develops and documents test procedures and schedules associated with conducting environmental ...
Bendable Smartphone Uses Display Made of Graphene
"As of now, graphene is too expensive to manufacture at an industrial scale, however, scientists are actively working on producing a cheaper more viable method to apply it to devices. The new smartphone displayed at the convention still lacks the standard image qualities set by LCD and OLED displays. Although the image quality may not be at par with current HD screens, the new bendable graphene touchscreen phone remains an exciting feature to look forward to when it will enable devices to be thinner, lighter, and incredibly tougher. Let us know in the comments below what you think ..."
"Do Engineers Complain Too Much About Pay?"
the Engineer, a UK website, recently did a reader poll titled "Do Engineers Complain Too Much About Pay?" It was a big hit. "We've rarely had such an emphatic response to a poll. Of the 591 readers who responded, 2/3 picked the option that engineers did not complain too much about pay and were not paid enough. Unfortunately, we can't separate out whether respondents were agreeing with both parts of the statement or only one. Of the remaining respondents, 15% thought that engineering ..."
Exploring Phosphorene as Super Fast Semiconductor
"Two-dimensional phosphane, a material known as phosphorene, has potential application as a material for semiconducting transistors in ever faster and more powerful computers. But there's a hitch. Many of the useful properties of this material, like its ability to conduct electrons, are anisotropic, meaning they vary depending on the orientation of the crystal. Now, a team including researchers at RPI has developed a new method to quickly and accurately determine that orientation using the interactions between light and electrons within phosphorene ..."
Pasternack PIN Diode Switches for 10 MHz to 67 GHz
Pasternack, a leading provider of RF, microwave and millimeter wave products, greatly expands their portfolio of in-stock solid state PIN diode switches covering frequencies from 10 MHz to 67 GHz. 69 unique new models of 50 ohm PIN diode switches are available in compact connectorized package styles and display impressive isolation, insertion loss, and switching speed performance. Pasternack's new PIN diode switches offer a broad range of solutions in applications where fast switching and long lifetime are ...
Quantum Filter Integrates 20,000 Josephson Junctions
"Arrays containing as many as 20,000 Josephson junctions have been created by physicists at CSIRO in Australia. The devices are made from a high-temperature superconductor and operate at liquid-nitrogen temperatures. With further development, the devices could be used in a range of applications, including magnetic-field sensing and as radio-frequency antennas. The devices are called superconducting quantum interference filters (SQIFs), which are 2D arrays of superconducting interference devices (SQUIDs). A SQUID is ..."
Thomas Edison in John Hancock Ad in The Saturday Evening Post
Presenting yourself or your company as being modeled after a person of great accomplishment has been a common promotional tactic for as long as there has been print media. The John Hancock chose in this issue of The Saturday Evening Post to suggest, albeit by an indirect approach, to elicit the admiration Americans had for Thomas Edison's lust for innovation and desire to make people's lives better in hopes that readers would associate Edison with the insurance company. While the juxtaposition is strained, I do like one line in particular, "He lured electricity into a bottle and taught it to glow with good cheer." This short tribute to on of the world's greatest engineers is worth your a few moments of your valuable time ...