 Friday 18 Thursday 17  All RF Cafe quizzes would make perfect fodder in employment interviews for technicians or engineers - particularly those who are fresh out of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons who are going to be interviewed for a job. This quiz is based on the information presented in High-Frequency Integrated Circuits, by Rosin Voinigescu.
 Sam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his October newsletter that features his short op−ed entitled "Coming: Plasma Antennas." Plasma antennas have been appearing in the news items I collect, and Sam does a pretty good job summarizing their operation and benefits. One feature I do not recall seeing elsewhere is that in the "off" state, the plasma antenna presents a very small radar cross section (RCS), which is strategically advantageous for stealth aircraft (and surface ships). In other news, Sam includes other news related to our RF industry ...
 Please take a few moments to visit the everythingRF website to see how they can assist you with your project. everythingRF is a product discovery platform for RF and microwave products and services. They currently have 227,460 products from more than 1210 companies across 285 categories in their database and enable engineers to search for them using their customized parametric search tool. Amplifiers, test equipment, power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything else. Please visit everythingRF today to see how they can help you.
 "Today's cellular networks and Wi-Fi systems rely on microwave radiation to carry data but the demand for more bandwidth is quickly becoming more than microwaves can handle. That has researchers thinking about transmitting data on higher frequency terahertz waves, which have as much as 100 times the data-carrying capacity of microwaves. But terahertz communication technology is in its infancy - there is much basic research to be done and plenty of challenges to overcome. It's been assumed that terahertz links would require a direct line of sight between transmitter and receiver ..."
 Nova Microwave is a leader in technically differentiated electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control critical commercial and military wireless telecommunications systems. Our staff is dedicated to research and development of standard and custom design quality Ferrite Circulators and Isolators from 380 MHz to 26.5 GHz. Available in single or multi-junction topographies, the Nova Microwave product line of is specifically designed for use in varied environmental and temperature extremes.
Wednesday 16  According to an item in this late 1944 issue of Radio News magazine, the six-hour delay which occurred between the time the armistice was signed at the end of World War I and the time news reached the battlefields, many men, women, and children on all sides died needlessly. Almost as many were maimed or injured. That might seem like a stretch, but in the 4 years, 3 months, and 2 weeks of the "the war to end all wars," an estimated 14 to 19 million lives were lost. It is an average of 375 to 500 casualties per hour, or 2,200 to 3,000 in six hours. Planners expected that the widespread availability of wireless communications (radio) meant that when the end World War II was finally announced, a cease fire on all fronts would be effected in less than half an hour ...
Characterizing Uncertainty in S-Parameter Measurements  A team of authors from the Federal Institute of Metrology (METAS), Berne-Wabern, Switzerland, have published an article in Microwave Journal entitled, "Characterizing Uncertainty in S−Parameter Measurements," which poses - and answers - the question, "If it is that easy to take two measurements and obtain different results, how can one know which measurement is correct?" "Every measurement, no matter how carefully performed, inherently involves errors. These arise from imperfections in the instruments, in the measurement process, or both. The 'true value of a measured quantity' (atrue) can never be known and exists only as a theoretical concept. The value that is measured is referred to as 'indication' or (aind) ..."
 Unlike other websites, I never require you to provide personal information in order to access someone else's (or my own) app notes / whitepapers. The app note entitled "Introduction to SAW Filter Theory & Design Techniques," by API Technologies, can be downloaded directly from the company website without registration. It begins, "In theory, an ideal filter would possess no loss, an instantaneous transition from the pass band to the stop band, infinite stop band attenuation, no signal distortion introduced by the filter and have very small size and cost. In reality, many tradeoffs need to be considered when selecting a filter for a system design. An advantage of SAW filter technology ..."
 At VidaRF, the phrase 'Providing Simple Solutions for Complex Connections' is more than just a slogan – it's a mindset, a mission, and a driving force behind everything we do. Their pledge is to design and distribute high performance, cost effective RF Microwave products to fit each customer's unique applications. Please visit VidaRF today to see how their lines of Attenuators & Terminations, Directional Couplers, Power Dividers, Coaxial Connectors, and Circulator & Isolators can be of use to your project. "When the standard just will not do, VidaRF has the solution for you!"
 Just as the test and measurement equipment manufactures scrambled to produce lines of spectrum, network and communications analyzers, oscilloscopes, power meters, electromagnetic field sensors, and many other types of products specifically for the cellphone and Wi-Fi industries, companies were scrambling to provide for the needs of FM radio and television development labs and production lines. This 1947 advertisement from Radio Corporation of America (RCA) is an example that appeared in Radio News magazine. In fact, TV was so new that just a few months later, in September of 1948, editor Hugo Gernsback changed the publication's name to Radio and Television News ...
 "Very thin nylon films were created that can be used in electronic memory components. The films are several hundreds of times thinner than a human hair and could be used in bendable electronic devices or for electronics in clothing. Nylon synthetic polymers consist of a long chain of repeated molecular units in which each repeated unit contains a specific arrangement of hydrogen, oxygen, and nitrogen with carbon atoms. Besides use in textiles, some nylons also exhibit ferroelectric properties - positive and negative electric charges can be separated and this state can be maintained. The ferroelectric materials are used in sensors, actuators, memories, and energy-harvesting devices ..."
 PCB Directory is the largest directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet. We have listed the leading printed circuit board manufacturers around the world and made them searchable by their capabilities - Number of laminates used, Board thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing, fabrication, assembly, prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
Tuesday 15  If you are a Ham radio operator - especially a DX (long distance) operator, you have been required to study and learn about how the various layers of the Earth's ionosphere can, under predictable conditions, be an excellent reflector of certain radio wavelengths, thereby facilitating over-the-horizon communications. Reading this article is like a flashback from the license preparation manuals - particularly for the General license exam. There is a lot of information here. When this article was published in a 1958 issue of Radio & TV News magazine, the world was nearing the end of the International Geophysical Year (IGY), which had as its goal learning as much as possible about the properties of the upper atmosphere. The first earth-orbiting satellites were being launched and manned space flight was only months away, so there was much interest in learning ...
 Rohde & Schwarz has published an app note entitled, "dB Or Not dB?" (a rather contrived attempt - yet not unlike something I might try to get away with - at an allusion to Shakespeare's "To be or not to be..."). The subtitle is, "Everything you ever wanted to know about decibels but were afraid to ask..." It begins, "%, dB, dBm and dB (μV/m) are important concepts that every engineer should understand in his (or her) sleep. Because if he does not, he is bound to be at a disadvantage in his work. When these terms come up in discussions with customers or colleagues, he will have trouble focusing on the real issue if he is busy wondering whether 3 dB means a factor of 2 or 4 (or something else). It is well worth the effort to review these concepts from time to time and keep familiar with them ..."
 A while back, I purchased a May 29, 1948, edition of The Saturday Evening Post, because it contained one of Charles Schulz's Li'l Folks (which became Peanuts) comics. There were a couple things that stood out as I perused the magazine. First was the vitriolic tone of the Letters to the Editor, ripping the publication for articles in previous editions. Another was that the majority of the artwork for stories and advertisements was either a painting or a pencil drawing - almost no photographs. There was not a single ad for any television set - B&W or color - even though RCA had been selling color sets for four years by that time. The following story was on the last page of the magazine. You'll get a kick out of its premise ...
 The 2019 IEEE International Symposium on Phased Array Systems and Technology will be held from October 15th through 18th at the Westin Hotel in Waltham, Massachusetts, on Boston's famous Route 128 Technology Highway. The symposium will include keynote and plenary sessions, parallel technical sessions, poster sessions, tutorials, and a student paper contest. Social events will include a welcome reception with dinner and an awards banquet. This symposium will present the most recent advances in phased array technology and provide a unique opportunity for members of the international community to interact with colleagues in the field of phased array systems and technology.
 "After many years of continuous growth, the global smartphone market saw a slowdown in 2018. This slowdown had a direct impact on the RF Front-End market which also saw a decline in demand last year. According to a recent Yole Développement (Yole) report, 5G will come to the rescue and drive the RF Front-End market to grow at a CAGR of 8% from 2018 to 2025. The market was estimated to be USD $15B in 2018, and is expected to reach USD $25.8 billion by 2025. With LTE, RF front-end market growth came from carrier aggregation and MIMO technologies. 5G will augment RF front-end market ..."
 Empower RF Systems is a global leader in power amplifier solutions. Empower RF Systems is an established and technologically superior supplier of high power solid state RF & microwave amplifiers. Our offerings include modules, intelligent rack-mount amplifiers, and multi-function RF Power Amplifier solutions to 6 GHz in broadband and band specific designs. Output power combinations range from tens of watts to multi-kilowatts. Unprecedented size, weight and power reduction of our amplifiers is superior to anything in the market at similar frequencies and power levels.
Monday 14  Once upon a time, all non-passive electronic products and test equipment used vacuum tubes. Since tube diodes need a voltage bias, even something as simple as a rectifier circuit was "active." Even though modern day transistorized equipment has largely overcome most of the disadvantages of solid state versus vacuum tube, in the early days of silicon and germanium transistors and diodes issues like voltage and power handling and input impedance was a limiting factor to some applications. Until the advent of rugged and reliable field-effect transistor (FET) transistors, if you needed a very high input impedance for an oscilloscope or multimeter, a vacuum tube circuit was a necessity. A high impedance test instrument input is required with high impedance device under test (DUT) in order to avoid loading down ...
 The Association of Old Crows is holding their 56th Annual AOC International Symposium Convention in Washington, D.C., on October 28-30. It is regarded as the industry's leading event and brings together nearly 2000 professionals from 30+ countries spanning industry, military, and government sectors. "Learn from subject matter experts and influencers from military, government, academia and industry who will speak to a multitude of topics around the theme of 'Building the EMS Enterprise.' Whether it is from a main stage keynoter, a breakout session panelist, or an Innovation Stage message, plan to walk away equipped with the latest developments in technology and governance in pursuit of EMS capability superiority. ..."
 Here is an advertisement for Delco radios that I scanned from my copy of the April 1945 QST magazine. "'Control the Air' has a new meaning today." That's the tag line referring to the need to dominate wireless communications in the effort to conduct effective warfare. Radio certainly wasn't a new science in 1945, but secure communications - including spread spectrum techniques - was a vital technique both for transmitting and receiving messages and for jamming the communication of our enemies. Even though Hollywood actress Hedy Lamarr and music composer George Antheil came up with the concept of frequency hopping spread spectrum in the early years of World War II, the U.S. Department of War stuck mostly with codebook encryption techniques ...
 This article entitled "Avoiding Electrical Damage with Conductive Lubrication" appeared in the October 2019 edition of NASA's Motion Design publication. It highlights the new problems being faced by automotive design engineers as they replace 12 V electrical systems, which have been the standard for over half a century, with increasingly preferred 48 V systems. The motivation (pun not intended) is, among other things, to enable use of smaller gauge wire, and the resulting lower weight and expense, in the ever-increasing amount of electrical cabling in modern vehicles. The downside of a higher voltage is a larger difference of potential induces larger leakage currents in metallic components without bonded connections - as in bushings and ball bearings. Engineers and scientists are now developing conductive lubricants to help mitigate the problem ...
 "Imperfections in diamond enable a 10-qubit register - a collection of qubits that can store data in a quantum computer - report researchers at Delft University of Technology in the Netherlands and Element Six in the UK. Their diamond-based system is capable of preserving an arbitrary single-qubit state for over a minute - a record for a solid-state qubit. The multiqubit register signifies important progress in quantum-information processing, which requires a large number of qubits. Realizing multiqubit registers is challenging for two reasons: the quantum gates require selective control of qubits, and unwanted interactions must be avoided ..."
 Anatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed.
Sunday 13  For two decades, I have been creating custom engineering- and science-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. This October 13, 2019, puzzle contains the names of at least eight advertisers* who help deliver RF Cafe to you every day. Otherwise, it uses a database of thousands of words which I have built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which ...
|  Exodus Advanced Communications is pleased to introduce our high power 10 kHz to 100 MHz 1000-watt, class A/AB linear LDMOS, rack mountable amplifier. Exodus AMP2080E-1 produces 1000 W minimum, >1100 W nominal power, P1dB 700 W typical. The minimum power gain is >60dB with excellent gain flatness. Included are amplifier monitoring parameters for Forward/Reflected power, VSWR as well as voltage, current & temperature sensing for optimum reliability & ruggedness for all applications. Nominal weight is 120 lbs., and dimensions of 19"W x 30"L x 17.5"H ...
 This photo from an article entitled, "Exploring Electronics with Simple Projects," which appeared in a 1958 issue of Popular Electronics magazine, made me think of "The Radio Boys" series of books written in the 1920s. A shorter series entitled "The Radio Girls" appeared as well. Both titles told tales of a group of youngsters who were caught up in the "wireless" craze of the era. They built their first receivers entirely from homemade parts, including winding the tuning coil and fashioning a moveable tap on the coil. Motivated by more knowledgeable adults - of which there were few in the day - the kids progressed on to single-tube sets and then, after earning their licenses, built and operated transmitters. Today such do-it-yourselfers are called "Makers," and there is an entire industry and culture ...
 How's Your Radio Geography?
 RF Cafe typically receives 8,000-15,000 website visits each weekday and about half that on weekends. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 7,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn, Facebook, and Twitter. If you need your company news to be seen, RF Cafe is the place to be. Banner advertising begins at $175/month ...
 RF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features ...
 With more than 780 custom-built symbols, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every object has been built from scratch to fit proportionally on the provided A- and B-size drawing page templates (you can use your own page if preferred). Components are provided for equipment racks (EIA and ETSI) and test equipment, system block diagrams and conceptual drawings, and for schematics ...
|  "Recently discovered two-dimensional (2D) materials with superlative properties have the potential to advance semiconductors but creating 2D devices with both good electrical contacts and stable performance has proved challenging. A nearly ideal transistor made from a two-dimensional material stack - with only a two-atom-thick semiconducting layer - was fabricated using a completely clean and damage-free fabrication process. The method shows vastly improved performance compared to 2D semiconductors fabricated with a conventional process and could provide a scalable platform for creating ultra-clean devices in the future. The two-step, ultra-clean ..."
 "Silver dipoles are arranged across the folds of a Miuri-Ori pattern to enable frequency blocking. Researchers at the Georgia Institute of Technology have devised a method for using an origami-based structure to create radio frequency filters that have adjustable dimensions, enabling the devices to change which signals they block throughout a large range of frequencies. The new approach to creating these tunable filters could have a variety of uses, from antenna systems capable of adapting in real-time to ambient conditions to the next generation of electromagnetic cloaking systems that could be reconfigured on the fly to reflect or absorb different frequencies. The team focused on one particular pattern of origami ..."
 "Researchers from Japan have developed a highly sensitive rectifying element in the form of a nanowire backward diode, which can convert low-power microwaves into electricity. The research was carried out by leading communication technology company, Fujitsu, in partnership with the Japan Science and Technology Agency (JST), and the Tokyo Metropolitan University. Through JST's Strategic Basic Research Programs, the technology was developed by researchers led by Kenichi Kawaguchi of Fujitsu Limited and Professor Michihiko Suhara of the Tokyo Metropolitan University. The new technology can generate electricity from ambient radio waves ..."
 "Researchers in Switzerland and the U.S. have a non-destructive technique that can reverse engineer an entire chip without damaging it. Ptychographic X-ray laminography can scan an entire chip or zoom in on a particular spot to reveal its circuits. Scientists and engineers in Switzerland and California have come up with a technique that can reveal the 3D design of a modern microprocessor without destroying it. Typically today, such reverse engineering is a time-consuming process that involves painstakingly removing each of a chip’s many nanometers-thick interconnect layers and mapping them using a hierarchy of different imaging techniques, from optical microscopy for the larger features to electron microscopy for the tiniest features ,... "
 "Researchers from the University of Maryland, the National Institute of Standards and Technology (NIST), the National High Magnetic Field Laboratory (NHMFL) and the University of Oxford have observed a rare phenomenon called re-entrant superconductivity in the material uranium ditelluride. The discovery furthers the case for uranium ditelluride as a promising material for use in quantum computers. Nicknamed "Lazarus superconductivity" after the biblical character who rose from the dead, the phenomenon occurs when a superconducting state arises, breaks down, then re-emerges in a material due to a change in a specific parameter - in this case, the application of a very strong magnetic field ..."
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