Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Forums Magazine Sponsor RF Cafe RF Electronics Symbols for Visio RF Electronics Symbols for Office Word RF Electronics Stencils for Visio Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Anritsu Alliance Test Equipment Amplifier Solutions Anatech Electronics Axiom Test Equipment Berkeley Nucleonics Bittele Centric RF Conduct RF Copper Mountain Technologies Empower RF everything RF Exodus Advanced Communications Innovative Power Products ISOTEC KR Filters Lotus Systems PCB Directory Rigol RF Superstore San Francisco Circuits Reactel RFCT TotalTemp Technologies Triad RF Systems Windfreak Technologies Withwave LadyBug Technologies Wireless Telecom Group Sponsorship Rates RF Cafe Software Resources Vintage Magazines Thank you for visiting RF Cafe!

Homepage Archive - September 2021 (page 2)

See Page 1 | 2 | 3 | 4 of the September 2021 homepage archives.

Tuesday the 14th

Modelithics Welcomes Dr. Ali Boudiaf as Director of Lab Operations

Modelithics Welcomes Dr. Ali Boudiaf as Director of Lab Operations - RF CafeModelithics, the leader in providing simulation models for RF, microwave, and mmWave devices is pleased to welcome Dr. Ali Boudiaf to the company as Director of Lab Operations. Dr. Boudiaf comes to Modelithics with 30 years of experience in the RF, microwave, and mmWave engineering arena. In his new role at Modelithics, his responsibilities include managing all aspects of lab operations as well as advancing Modelithics microwave and millimeter-wave test system capabilities. Prior to joining Modelithics, Dr. Boudiaf was the CEO and co-founder of Smart MedTech. He also previously worked at ERZIA Technologies as Director of Amplifier Systems. Dr. Boudiaf's prior experience also includes positions with Maury Microwave, Focus Microwaves, Agilent Technologies, and ATN Microwave...

Lights, Phones, Laptops Wirelessly Charge in the "Charging Room"

Lights, Phones, Laptops Wirelessly Charge in the "Charging Room" - RF Cafe"In a move that could one day free the world's countertops from their snarl of charging cords, researchers at the University of Michigan and the University of Tokyo have developed a system to safely deliver electricity over the air, potentially turning entire buildings into wireless charging zones. Detailed in a new study published in Nature Electronics, the technology can deliver 50 watts of power using magnetic fields. Study author Alanson Sample, U-M professor of computer science and engineering, says that in addition to untethering phones and laptops, the technology could also power implanted medical devices and open new possibilities for mobile robotics in homes and manufacturing facilities. The team is also working on implementing the system in spaces that are smaller than room-size, for example, a toolbox that charges tools placed inside it."

Scanning Electron Microscope for Radio Engineers

New Scanning Electron Microscope Revealed to Radio Engineers, September 1942, Radio-Craft - RF CafeTelevision and radio facsimile machine electronics technology was credited for aiding in the development of a new type of scanning electron microscope (SEM) that could image the surface of opaque object to a resolution of 100 angstroms (Å). The television contribution part of the technology was precisely controlling a raster path for the electron beam. The facsimile part was the knowledge of how to assemble a printed image from streaming data. It is interesting to note that in order for an object to be imaged via SEM, its surface must be electrically conductive. Accordingly, non-metallic objects like bugs, plants, plastic, wood, etc., must receive a coating of metal by a process such as sputtering. Doing so can leave a few atoms thick later without losing too much resolution due to softening of features...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeNew Scheme rotates all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000 website visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 16,000 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. If you need your company news to be seen, RF Cafe is the place to be.

Thanks Again for Windfreak Technologies' Continued Support!

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

Monday the 13th

Amateurs Honor Hiram Percy Maxim

Amateurs Honor Hiram Percy Maxim, August 1940 QST - RF CafeHiram Percy Maxim is well-known by amateur radio operators as the founder of the American Radio Relay League (ARRL). He died in 1936 and was buried at Rose Hill Cemetery in Hagerstown, Maryland. A few years ago while visiting relatives in Hagerstown, I went to the cemetery, took some photos, got the exact GPS coordinates, and posted a short article on it (see Hiram Percy Maxim's Gravesite in Hagerstown, Maryland). If not for my documentation, there would be no way to know that the large grave marker shown in this 1940 QST article does not belong to the esteemed Mr. Maxim, but to the matron of his wife's family, Maryland Governor William T. Hamilton. Hiram Percy Maxim's gravesite is marked by a non-descript flush marker. I found it to be a great disappointment. Maybe his in-laws never really took kindly to him...

Proton Cooled w/Ion Cloud and Superconducting Circuit

Proton Cooled w/Ion Cloud and Superconducting Circuit - RF Cafe"The ability to trap charged particles and cool them down to a fraction of a degree above absolute zero is key to many tests of fundamental physics, including probes of any asymmetry between matter and antimatter. To reach lower temperatures more quickly, physicists in Germany and Japan have now shown how to extract heat from a single proton via a superconducting circuit connected to a cloud of laser-cooled ions several centimeters away - a technique, they say, that could easily be applied to antiprotons. The Standard Model of particle physics tells us that all physical processes must obey CPT symmetry..."

Hobnobbing with Harbaugh

Hobnobbing with Harbaugh, March 1970 Popular Electronics - RF CafeHere is a little electronics hobbyist humor in the form of a comic series titled "Hobnobbing with Harbaugh," compliments of Dave Harbaugh in the March 1970 issue of Popular Electronics. Citizens Band radio and dirty hippies were the topic of the day in the 1970, so that's what you see in a couple of these comics. The marriage proposal comic can be considered as "amateur" in more ways than one! You don't need to be an amateur radio operator to appreciate these comic strips...

Firmware Engineer for Power Electronics Digital Control Needed by Aegis

Firmware Engineer for Power Electronics Digital Control Needed by Aegis Power Systems - RF CafeAegis Power Systems, a designer and manufacturer of power electronics, is seeking a Firmware Engineer to join our growing team for an on-site position in the beautiful mountains of North Carolina! Aegis Power Systems, Inc., is seeking to design, develop, and maintain digital control for power electronics hardware. Come join our growing team for an on-site position in the beautiful mountains of North Carolina! The Firmware Engineer is responsible for ensuring firmware programming meets customer demands and internal development projects. This position works closely with our electrical engineers who design AC/DC, DC/DC, and DC/AC converters and inverters using a variety of power topologies. Candidate must have a programming background using microcontrollers for use in real time analog and digital controls with serial interfaces...

Many Thanks to San Francisco Circuits for Continued Support!

San Francisco CircuitsSF Circuits' specialty is in the complex, advanced technology of PCB fabrication and assembly, producing high quality multi-layered PCBs from elaborate layouts. With them, you receive unparalleled technical expertise at competitive prices as well as the most progressive solutions available. Their customers request PCB production that is outside the capabilities of normal circuit board providers. Please take a moment to visit San Francisco Circuits today. "Printed Circuit Fabrication & Assembly with No Limit on Technology or Quantity."

Sunday the 12th

RF Directional Coupler Theme Crossword for September 12

RF Directional Coupler Theme Crossword Puzzle for September 12, 2021 - RF CafeThis week's crossword puzzle has an RF Directional Coupler theme in that many of the words are related to the devices. All of the other words are, as usual, pulled from a custom-built dictionary containing only terms pertaining to engineering, mechanics, astronomy, mathematics, chemistry, and names of companies that make components for the aforementioned fields. Even Dilbert characters appear sometimes. You will not, however, find names of numbnut Hollywierd celebs or TV shows here...

Friday the 10th

Rider Service Manuals

Rider Service Manuals, April 1948 Radio News - RF CafeSams Photofact, by the Howard W. Sams Company, was undeniably the big name in electronics equipment service manuals in the 1947 timeframe, but they were not the only game in town. Rider Perpetual Troubleshooters Manuals were probably the next biggest when this promotion appeared in Radio News magazine. Rider had a very different approach to page layout and content compared to Sams Photofact publications. No instances of any of the manuals showed up on eBay when just checked, but the World Radio website has many of them posted for viewing...

NEETS - Introduction to Solid-State Devices

NEETS Introduction to Solid-State Devices and Power Supplies - RF CafeThe discovery of the first transistor in 1948 by a team of physicists at the Bell Telephone Laboratories sparked an interest in solid-state research that spread rapidly. The transistor, which began as a simple laboratory oddity, was rapidly developed into a semiconductor device of major importance. The transistor demonstrated for the first time in history that amplification in solids was possible. Before the transistor, amplification was achieved only with electron tubes. Transistors now perform numerous electronic tasks with new and improved transistor designs being continually put on the market. In many cases, transistors are more desirable than tubes because they are small, rugged, require no filament power, and operate at low voltages with comparatively high efficiency. The development of a family of transistors has even made possible the miniaturization of electronic circuits...

GaN-Based Complementary Logic ICs

Gallium nitride-based complementary logic integrated circuits - RF Cafe"Most integrated circuits (ICs) and electronic components developed to date are based on silicon metal-oxide-semiconductor (CMOS) technology. As silicon (Si) is known to have a narrow bandgap, however, in recent years engineers have been trying to develop ICs using other materials with a wider bandgap, such as gallium nitrite (GaN). ICs made of GaN could have notable advantages over conventional ICs based on silicon, particularly for the development of power electronics, radiofrequency power amplifiers and devices designed to operate in harsh environments. However, so far developing GaN CMOS logic circuits has proved to be highly challenging, due to the intrinsically low mobility of holes in the material and the lack of a suitable strategy for integrating n-channel and p-channel..."

Lead Electronics Technician Needed by Aegis

Lead Electronics Technician Needed by Aegis Power Systems - RF CafeAegis Power Systems, a designer and manufacturer of power electronics, is seeking a Lead Electronics Technician to join our growing team for an on-site position in the beautiful mountains of North Carolina! The Lead Electronics Technician supports the development and implementation of tests to evaluate, verify, troubleshoot, and repair our power supply products. This includes designing test fixtures to support test events, setup of test equipment, collecting data during test events, troubleshooting and root cause analysis during failures, and advising on repairs or alternate design paths. This position works closely with design engineers and production staff to test and resolve challenges in our power supply products. The Lead Electronics Technician must have a thorough knowledge of AC and DC circuitry, schematics interpretation...

Use it up, Wear it out, Make it do, Or do without

Use it up, Wear it out, Make it do, Or do without, March 1944 Radio-Craft - RF Cafe"Use it up... Wear it out... Make it do... Or do without" - what a great slogan! It was coined by the War Advertising Council during World War II to promote the dual need to conserve scarce resources and to help keep prices down by not generating excess demand. Most of us have seen videos or read articles about neighborhood materials collection efforts to round up old tires, scrap metal, glass, tools, electronics equipment, cloth and clothing, and many other items that could be recycled for used directly in the war effort. There was also an undertone of not abetting attempts by opportunists to profiteer off the war. Government policy did what it could to control the economy by instituting severely progressive income taxes and price controls (that way only the ultimate insiders could get rich). After 11.3% and 7.6% inflation rates...

Many Thanks for Alliance Test Equipment's Support!

Allied Test Equipment Products - RF CafeAlliance Test Equipment sells used / refurbished test equipment and offers short- and long-term rentals. They also offer repair, maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization with ability to source hard to find equipment through our network of suppliers. Alliance Test will purchase your excess test equipment in large or small lots. Blog posts offer advice on application and use of a wide range of test equipment. Please visit Allied Test Equipment today to see how they can help your project.

Thursday the 9th

High Frequency Heating at a Glance

High Frequency Heating at a Glance, May 1945 Radio-Craft - RF CafeChances are when you think about high power RF frequency sources, it pertains to transmitters for analog or digital data, or maybe for imaging applications like x-ray machines. There is, however, another very large industry that uses high frequency electromagnetic energy for heating of materials in product processing. Frequencies range from tens of kilohertz to tens of megahertz, with power levels into the megawatt realm. This article from a 1945 edition of Radio-Craft points out a few applications used in the day, and now there are many more areas where high power RF is used. Adhesive curing is a major area, especially for laminated materials like plywood and composite structures. Decontamination of medical and food products is another. Both inductive and capacitative heating methods are used in metals processing...

Solar Polarization Paradox Resolved

Solar Polarization Paradox Resolved - RF Cafe"A paradox that puzzled a generation of solar and atomic physicists - and occasionally pitted theories from one field against the other - has been resolved. The paradox concerns the polarization of light at a specific point in the solar spectrum, and previous attempts to explain it required either an extreme reduction in the Sun's magnetic field (which solar physicists deemed unlikely) or changes to the physics of atom-photon interactions (which atomic physicists did not observe). The latest research, however, indicates that no such adjustments are needed. Instead, careful numerical modeling showed that the discrepancy between solar observations and atomic theory vanishes after complex, previously neglected interactions are taken into account. Most sunlight is at least partly linearly polarized..."

Carl & Jerry: The Sparking Light

Carl & Jerry: The Sparking Light, May 1962 Popular Electronics - RF CafeIn this adventure from a 1962 issue of Popular Electronics magazine, Carl and Jerry use a pair of General Electric pnpn junction photoelectric switches to exact revenge on an engineering student 'friend' at Parvoo U. It involves embarrassing the guy in the presence of his YL (Hamese for young lady) date. The switches, per Jerry's tutelage, work like a silicon-controlled rectifier (SCR), except light is used to trigger the conduction path rather than an electrical gate signal. The devices are "solid-state kissing cousins of vacuum tube thyratrons." That's not necessarily the way I would have put it, but OK. You are also treated to a discussion of how and why to tame a chattering relay with a diode rather than a big capacitor. Author and creator John T. Frye ceased writing the stories before the two boys graduated from college, so we'll never know what became of them.

New for 2021! RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, 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 to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Stencils are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing. The file format is XML so everything plays nicely with Visio 2013 and later...

Please Thank RF Superstore for Their Continued Support

RF Superstore coaxial cable, connectors, adapters - RF CafeRF Superstore launched in 2017, marking the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally changed the way RF components were sold. Partner Jason Wright manages day-to-day operations, while working closely with Mr. Pasternack to develop RF Superstore into a world class RF and microwave component supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies, surge protectors, attenuators. Items added daily. Free shipping on orders over $25. We're leading the way again!

Wednesday the 8th

Simulations of Polymers a Quantum Puzzle

Simulations of Polymers a Quantum Puzzle - RF Cafe"Using computers to study polymers has always been a major challenge for scientific computation, especially for long and densely packed biomolecules, like DNA. New perspectives are now opening up through quantum computing. Scientists have now recast the basic models of polymer models as optimization problems that can be efficiently solved with quantum computers. This novel approach has made it possible to harness the considerable potential of these machines in a hitherto unexplored context. Many of the paradigms of scientific computing, from Monte Carlo techniques to simulated annealing - the authors explain - were developed, at least in part, to study the properties of polymers, including biological ones such as protein and DNA..."

ConductRF Performance Flexible RF Cables to 18 GHz

ConductRF LSA Performance Flexible RF Cables to 18 GHz, September 7, 2021 - RF CafeConductRF LSA series of Low Loss, Performance flexible RF cable assemblies, provide microwave system designers with a versatile solution for most applications. Here we offer customers a solution for 0.086" dia. cable that facilitates greater flexibility and handling or, 0.141" dia. that exploits the same great performance but with almost half the loss. Connector options include SMA, Type-N, TNC & SMP that provide excellent VSWR between DC and 18 GHz, also solutions for MCX & SMB are available in a wide array of configurations. These assemblies are built using our own double shielded, FEP jacketed cable, that was developed specifically for performance solutions. With shielding effectiveness exceeding 90 dB through 18 GHz, these cables minimize the threat of cross-talk effect...

Station Design for DX

Station Design for DX (Part III), November 1966 QST - RF CafeIn 1960, Paul Rockwell wrote a 4-part series for the ARRL's QST magazine on station design for long distance communications (DX) that covered antenna selection and siting (Part I), economics and construction (Part II), station configuration and receiver topics (Part III), and propagation quirks and operating tips (Part IV). This is part III, which discusses topics such as receiver preamplification, preselectivity and matching, audio and intermediate frequencies. A detailed example block diagram illustrates the various components comprising a typical DX station.

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). 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

Many Thanks to Reactel for Their Long-Time Support!

Reactel Filters - RF Cafe

Reactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.


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. About RF Cafe.

Homepage Archive Pages

2022:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2021:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2020:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2019:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2018:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2017:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2016:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2015:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2014:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2012:  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 (no archives before 2012)

Amplifier Solutions Corporation (ASC) - RF Cafe
RF Electronics Shapes, Stencils for Office, Visio by RF Cafe
Anatech Electronics (RF Filters) - RF Cafe

Exodus Advanced Communications Best in Class RF Amplifier SSPAs

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free


About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    Kirt Blattenberger,


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 World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website: