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 Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Forums Magazine USAF Radr Shop Sponsor RF Cafe RF Electronics Symbols for Visio RF Electronics Symbols for Office Word RF Electronics Stencils for Visio Thank you for visiting RF Cafe!
Berkeley Nucleonics Academy RF Boot Camp - RF Cafe
ConductRF Phased Matched RF Cables - RF Cafe

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:


RF Superstore (RF Components) - RF Cafe

- Welcome to the RF Cafe Website -
Remember When ... a dress shirt, tie, and sport jacket were the uniform of the day?

Today in Science History

Tech Industry Headlines

Tech Industry Headlines - RF Cafe - Archive -

• Semi Content in Electronic Systems Tops 33%

• 8 U.S. Schools and Organizations Host Ham Radio Contacts with ISS

• Post-Lithium-Ion Battery Breakthrough

• Magnetic Surprise Revealed in "Magic-Angle" Graphene

• Free Mobile's 5G Footprint Reaches 77% of France

• Chinese Lab Claims >206 Gbps in 6G Mobile Technology

• Wealth of World's 10 Richest Men Doubled During Plandemic 

• 6G Research Collaborative Efforts in Initial Phase

• China's Chang'E-5 Detects Water on Moon

Serviceman's Experiences

Serviceman's Experiences, July 1938 Radio News - RF CafeAs I have reminded you many times when posting these articles from vintage electronics magazine like the 1938 Radio News, in-home service calls were commonplace for just about everything serviceable in the house. That included humans - particularly children - who were tended to in domus by their family doctors. Successful servicemen learned the lesson related in this story: "I work on the set owner in the house, and save the set work for the shop." That of course holds true for situations where the radio, television, record player, etc., needed to go back to the shop for repair. When repairs could be effected in situ, a combination of customer relations and technical skills was required. In addition to the aforementioned, another skill that needed to be honed was getting the customer to pay his bill. There were no credit cards in the day, so cash or an in-store line of credit was required for payment. In most cases the customer did not already have that credit line. If a piece of equipment is in the shop, then it can at least be sold in lieu of payment, but walking out of someone's house...

Basic Navy Training Courses: Transformers

NAVPERS 10622 Chapter 20: Transformers - Basic Navy Training Courses - RF CafeElectronics technicians trained by the U.S. Navy (and, ahem, the U.S. Air Force) have always been highly regarded in private industry because of the excellent classroom instruction, rigorous on-the-job training (OJT), and hands-on experience maintaining both legacy and state-of-the-art equipment. Electronics tech schools begin with teaching the fundamentals of electricity and electronics, and then branches off into areas of specialty, depending on the type of equipment the enlistee will be assigned to maintain. The military works under the assumption that you have no significant former knowledge of the topic - although being admitted into certain programs requires passing an aptitude exam prior to enlistment. This NAVPERS 10622 course chapter introduces concepts and governing equations for transformers...

Electron's Wave Nature Constructed in Lab

Electron's Wave Nature Constructed in Lab - RF Cafe"Researchers at the University of California at Santa Barbara in the US have reconstructed a representation of the electron's wave nature - its Bloch wave function - in a laboratory experiment for the first time. The work could have applications in the design and development of next-generation electronic and optoelectronic devices. Like all matter, electrons behave as both particles and waves. One of the main goals of condensed-matter physics is to understand how the wavelike motion of electrons through periodically-arranged atoms give rise to the electronic and optical properties of crystalline materials. Having such an understanding is especially important when designing devices that take advantage of the electron's wavelike nature, explains Joseph Costello, who co-led the UC Santa Barbara team..."

Antenova Atta Embedded Antenna for 410/450 MHz LTE

Antenova Atta Embedded Antenna for Remote Devices 410/450 MHz LTE - RF CafeAntenova Ltd, the UK-based manufacturer of antennas and RF antenna modules for M2M and the IoT, has revealed its latest antenna, Atta, part number SRFI079, for LTE and smart wireless deployments in the 410 MHz and 450 MHz bands. The Atta antenna is a flexible printed circuit (FPC) form and measures 101.0 x 20.0 x 0.15 mm. It is supplied with an I-PEX mating connector for direct integration to a circuit board, and a self-adhesive pad to fix it easily in position. It is therefore easy to integrate into a design. The LTE 450 spectrum is relatively new, with 65 deployments in North America, South America, Europe, Africa and Asia, and LTE 450 is available in 25 of these. This is expected to grow, as spectrum is allocated in more regions...

Dynamic Soaring and Pumped Laser Systems

Dynamic Soaring and Pumped Laser Systems - RF CafeYou have heard of the pumped laser and maser. Here is a new type of pumped energy system: the "vaser." "Laser" is an acronym for "light amplification by stimulated emission of radiation," and "maser" is an acronym for "microwave amplification by stimulated emission of radiation." I coined the term "vaser" after reading an article in the June 2014 edition of Model Aviation about a relatively new form of radio controlled (R/C) model sailplane sport - dynamic soaring - that, using a specially developed technique to exploit geography and prevailing winds, produces aircraft speeds of more than 400 miles per hour. Per my definition, "vaser" is an acronym for "velocity amplification by stimulated enhancement of energy" (OK, it's a lame attempt at being clever). It occurred to me that the mechanism used to add energy to electrons in atoms is fundamentally the same as that used to add energy to the sailplane in dynamic soaring. In pumped laser and maser systems, an external power source (stimulus) is used to cyclically add energy...

Identify That Chassis

Identify That Chassis, June 1958 Radio-Electronics - RF CafeHaving spent many years professionally scouring the Internet while attempting to identify electronic components as part of a reverse engineering effort, I can appreciate how difficult life would be when the only resources available were a few manufacturers' databooks and a magazine article or two. You might think it would behoove a company to make certain that its products are clearly marked if not with a part number, at least with an easily identifiable logo. That way a researcher could call the company, describe the part, and get the required information. Even with today's nano-size packages, laser marking could do the job. Sometimes, the maker of the next higher assembly (which might be the finished product) purposely either removes the identification from select components or instructs the vendor to only partially mark or not mark the package. That is done for competition reasons specifically to prevent or make very difficult the reverse engineering of products. You have likely seen "teardowns" of consumer electronic items like smartphones...

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 stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Thanks to Amplifier Solutions Corporation for Continued Support!

Amplifier Solutions Corporation (ASC) - RF Cafe ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using gallium nitride (GaN), gallium arsenide (GaAs) and silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz.

Carl and Jerry: Joking and Jeopardy

Carl and Jerry: Joking and Jeopardy, December 1963 Popular Electronics - RF CafeThis episode of John T. Frye's "Carl and Jerry" technosaga entitled "Joking and Jeopardy" is another of the slightly far-fetched adventures of the popular pair of electronics hobbyist chums, but as usual the story is a combination of drama and technical instruction. In this case it involves a remote-controlled model submarine which is signaled underwater by a pulsed ultrasonic transducer. The receiver decoded commands by causing a stepper relay (not a stepper motor) to increment a predetermined number of spaces to make the craft dive or surface, turn left or right, or start and stop. Remote control systems for models - be they airplanes, cars, or boats - did not have the luxury and convenience of proportional control in 1963 when this appeared in Popular Electronics magazine as we have nowadays...

UK RF/Microwave: Birthplace of Radar and Gas MMIC

The RF/Microwave Industry in the UK and Ireland, Birthplace of Radar and the GaAs MMIC - RF CafeHelen Duncan has an interesting article in the January 2022 issue of Microwave Journal magazine entitled "The RF/Microwave Industry in the UK and Ireland, Birthplace of Radar and the GaAs MMIC." In it, she recounts the proud history of her native country's role in research, development, and system production beginning with "The Father of Radar," Robert Watson Watt (a great surname for an electronics guy), and Arnold Wilkins during World War II. She writes, "This review of the microwave marketplace in my home country is inevitably a more personal one than those in previous years. In addition to profiling some of the main players in the market in 2021, I will reflect on some of the home-grown heroes of the microwave industry in the U.K. and Ireland who have influenced my own career and whose achievements continue to shape the landscape today..."

Kirt's Cogitations #216 - Points of Inflection

Kirt's Cogitations #216 - Points of Inflection - RF CafeWhen reading technical articles, I very often see the authors incorrectly refer to a certain point on a curve as being the inflection point. It is not merely a point at which a curve changes direction. That was the case in an article I read today that dealt with open-loop polar modulation in EDGE amplifiers. There exists an unambiguous definition of an inflection point, and all engineers were taught it in school. Pardon me if this seems trivial or picayune, but the purpose of the magazine articles is to teach, so if this factoid can eliminate the misconception in future articles, then it will have accomplished its objective. Here is a brief review of what an inflection point is, and, equally important, what an inflection point is not. An inflection point is the point at which the second derivative of a continuous curve equals zero. Accordingly, it is the point where a curve changes from concave up to concave down. A curved region is concave up if all the data points in that region lie above a line tangent to it. A curved region is concave down if all the data points in that region lie below a line tangent to it. The Excel plot that accompanies this article illustrates all of these concepts...

Bittele Electronics Fast and Easy Online Ordering Service

Bittele Electronics Fast and Easy Online Ordering Service 2022 - RF CafeBittele Electronics, a Toronto-based Turn-key PCB Assembly firm specializing in prototype and low-to-mid volume printed circuit board (PCB) manufacturing and assembly, is highlighting its very successful Online Ordering Service featuring Live Chat and Zoom meeting support. This new, state-of-the-art tool allows customers to complete turnkey PCB assembly orders faster and with up to 25% price discounts. Bittele's Online Ordering Service enables a customer to complete all steps to complete a PCB Fabrication and Assembly order in under 20 minutes while qualifying for exclusive discounts that are automatically applied to the order. Once an online order is placed, it will be immediately processed and released to Bittele's production team. "Our goal with this service is to help simplify our customers' ordering experience, as well as giving them attractive benefits..."

Nanowire Transistor w/Integrated Memory for Supercomputers

Nanowire Transistor w/Integrated Memory for Supercomputers - RF Cafe"For many years, a bottleneck in technological development has been how to get processors and memories to work faster together. Now, researchers at Lund University in Sweden have presented a new solution integrating a memory cell with a processor, which enables much faster calculations, as they happen in the memory circuit itself. In an article in Nature Electronics, the researchers present a new configuration, in which a memory cell is integrated with a vertical transistor selector, all at the nanoscale. This brings improvements in scalability, speed and energy efficiency compared with current mass storage solutions. The fundamental issue is that anything requiring large amounts of data to be processed, such as AI and machine learning, requires speed and more capacity. For this to be successful, the memory and processor need to be as close to each other as possible..."

The Remarkable Transistor Observes Its 10th Birthday

The Remarkable Transistor Observes Its 10th Birthday - RF CafeJust before Christmas in 1947, Bell Labs' John Bardeen, Walter Brattain, and William Shockley announced their invention of the first semiconductor device capable of producing positive signal amplification. They dubbed it the "transistor" because it was a transconductance amplifier. In very short order, the laboratory experiment consisting of a metallic point contact (a piece of gold foil) interfaced with a slab of purified and doped germanium became commercially available at a price that easily competed with a vacuum tube amplifier when the cost of the socket and high voltage biasing transformers were factored in. Transistors would not be able to entirely replace tubes for many decades, especially for high power and high frequency applications, but as you can see today, the only vacuum tube the average person will find anywhere...

Promote Your Company on RF Cafe for As Little As $40/Month

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 12,000 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.

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Electrical Engineering Theme Crossword for January 16th

Electrical Engineering Theme Crossword Puzzle for January 16th, 2022 - RF CafeThis custom made crossword puzzle for January 16th, 2022, from RF Cafe has an electrical engineering theme. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword puzzle contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Transistor Dictionary

Transistor Dictionary, May 1958 Radio-Electronics - RF CafeA few (many, actually) new terms have been added to the transistor lexicon since 1958, but this list from Radio-Electronics magazine contains more than 150 definitions that are still useful today. It is amazing that this list was created just a decade after the transistor was invented, and now half a century later the most commonly used terms have not changed much. A huge number of elemental compounds, configurations, and process terms have been added since then, though. All of these are included in my custom dictionary used for creating the weekly crossword puzzles - compiled over more than two decades...

Hobnobbing with Harbaugh: School Days

Hobnobbing with Harbaugh: School Days - School Days, December 1963 Popular Electronics - RF CafeDave Harbaugh did a number of different humorous features for Popular Electronics magazine back in the 1960s and '70s (see list at bottom of page). "Hobnobbing with Harbaugh" was one of the more popular comic series he did. Article topics ranged from husband-wife relationships where the husband is an über-enthusiastic technophile of some sort and the wife has to put up with his crazy schemes and inventions. These comics poke fun at technical schools and colleges, and their alumni. My favorite is the "suicidal" waveform.

Quantum Radar Might Boost Accuracy

Quantum Radar Might Boost Accuracy - RF Cafe"A combined team of researchers from the University of Arizona and MIT reports that quantum radar might be able to boost the accuracy of radar systems more than has been thought. In their paper published in the journal Physical Review Letters, the group describes a new approach to developing quantum radar and the obstacles that stand in the way of its development. Radar works by firing microwave radiation at an object and then measuring the signals that bounce back from it. And while quite effective for many applications, it still falls short for long-distance applications. Over the past few decades, as scientists came to learn more about quantum entanglement, some suggested it might be used to improve radar systems. And indeed, sending just one of two paired photons to a target..."

Greek Alphabet Quiz

Greek Alphabet Quiz, December 1963 Popular Electronics - RF CafeThis "Greek Alphabet Quiz" created by Robert Balin appeared in the December 1963 issue of Popular Electronics magazine. Years from now most people will probably have forgotten about how prominently Greek letters appeared in the news in this current era (2022) regarding the COVID-19 plandemic and the destruction caused by politicians and others with power and financial agendas. Delta and Omicron variants (but notably not Xi since it might offend the leader of the country of the virus' origin) are the most publicized. For centuries prior, from a scientific and engineering perspective we looked either positively or benignly toward Greek letters when assigning them as unique identifiers for quantitative units or physical configurations. When Robert Balin created this "Greek Alphabet Quiz" for Popular Electronics magazine in 1963, he had no idea how the aforementioned people would manage to bastardize the revered letters. No vaccination, mask, or social distancing is required while working this quiz...

Please see the RF Cafe Homepage Archives for previous items of interest...

Exodus Advanced Communications Best in Class RF Amplifier SSPAs
Sponsor RF Cafe
TotalTemp Technologies (Thermal Platforms) - RF Cafe
RF Cascade Workbook 2018 by RF Cafe

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

These Are Available for Free