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 App Notes Calculators Education Engineering magazine articles Engineering software Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Stencils for Visio RF & EE Shapes for Word Advertising RF Cafe Homepage Thank you for visiting RF Cafe!
Exodus Advanced Communications

- Welcome to the RF Cafe Website -
"The slide rule helped to design the very machines that would render it obsolete." - Robert Ragen

Today in Science History

Tech Industry Headlines

Tech Industry Headlines - RF Cafe- Archive -

• Automotive Production Stalled by Semiconductor Shortages

• Germany to Boost Chip Manufacturing in Wake of Auto IC Shortages

• European Operators Sign MoU and Commit to Open RAN

• Japan's Fugaku Supercomputer Tackling World's Biggest Problems

• Optical Data Transmission Speed Increased by at Least 10,000x

• Sweden Completes 5G Spectrum Auction in One Day

• Supreme Court Hears Media Ownership Arguments

• FCC Issues Multiple Citations for Unlawful Marketing of RF Devices

• Swedish 5G Auction Completes Despite Huawei Opposition

Radio Repair in Bed

Radio Repair in Bed, July 1945 Radio & Television News - RF CafeI learned a new word from this Radio-Craft article: "chemurgic," which refers to chemurgy, the science of creating products such as soybean gear shift knobs and cellulose movie film from agricultural raw components. It has nothing to do with the story other than to describe the town in which the subject, Wesley Rushing, lived. As the title suggests, Mr. Rushing established and thrived at a radio repair business built while confined to bed with a crippling illness. He worked an average of 10 hours per day and repaired two hundred radios each month. Although not a veteran himself due to his sickness, the story was offered as a means of support to the thousands of returning World War II veterans who suffered disabilities in battle. Today's handicapped veterans need and deserve similar encouragement, so if you have a can-do story, please submit it to one of the trade or hobby magazines; it will be greatly appreciated by many...

Embedded Trends and Tech to Watch in 2021 - RF Cafe"Shawn Prestridge, Lead FAE Engineer and U.S. FAE Team Manager at IAR Systems offers his insights and predictions about embedded development - the technology, markets, and tools - in 2021. We’ve seen R&D groups at large customers dabble with RISC-V to see if they want to base a platform on it, and we've seen smaller customers start to use it. A few large companies have really committed to using it in at least some business units. While part of the RISC-V trace specification was ratified this past February, there will still be a few tweaks made in 2021. Ultimately, you'll see a good deal of high-quality debug information like live instruction trace, interrupt visibility, power usage, and other metrics that can be fed through the debug port. Amongst other things, this will truly empower embedded developers to produce..."

Gain Efficiency with Fragmented-Aperture Phased Arrays

Gain Efficiency with Fragmented-Aperture Phased Arrays - RF CafeCarl Novello has an interesting article on the Electronic Design website entitled, "Gain Efficiency with Fragmented-Aperture Phased Arrays." I've always been skeptical of repetitive, pixelated type antenna patterns like the use of fractals and the seemingly random pattern (but probably computer optimized - looks Fragmented Phased Array looks like Space Invaders characters - RF Cafelike shapes from Space Invaders) used here. Evidently, there is something to it, though. He begins: "The world's demand for broadband connectivity has created a new generation of high-throughput satellites in geosynchronous Earth orbit (GEO), medium Earth orbit (MEO), and now low Earth orbit (LEO). But technology innovation in the ground segment has struggled to catch up to the space segment, especially when it comes to developing the most elusive of all antennas: Those that are low-cost and electronically steerable to power these next-generation, lower-orbit satellite networks. Electronically steerable antennas (ESAs), often referred to as flat panels..."

Bell Telephone Laboratories Salutes 3 New Nobel Prize Winners

Bell Telephone Laboratories Salutes Three New Nobel Prize Winners, February 1957 Radio & Television News - RF CafeAnyone visiting RF Cafe (other than by accident) almost certainly knows of Drs. Bardeen, Brattain and Shockley fame for their transistor invention while jointly working at the Bell Telephone Laboratories. The trio shared The Nobel Prize in Physics in 1956. Bell was so proud of their employees' efforts that they ran full page advertisements to boast of the accomplishment. This one appeared in the February 1957 edition of Radio & Television News. Alas, Ma Bell's moment of glory was a bit diminished by needing to add a footnote admitting that Drs. Bardeen and Shockley no longer work there. Note that while the ad says the transistor was announced in 1948, the first demonstration to Bell managers was in December of 1947...

Out of Order: Of Pointy-Haired Bosses

Out of Order: Of Pointy-Haired Bosses  - RF CafeThis story, submitted by RF Cafe visitor Jerry L., of Cincinnati, OH, reminds me of a certain manager in a popular engineering comic strip. Do you have a good work-related anecdote to share in the "Out of Order" feature? Please email it to me for consideration. Jerry Writes: "I worked in the defense electronics industry for my entire career and it is hard to think of a project in more than four decades that was not made infinitely more difficult due to the 'helpful' input of project managers. One experience in particular comes to mind as a perfect topic for your Out of Order feature. In the mid 1970s I was a "fresh-out," as new engineering college graduates were called at the time. Newly minted as a Masters degreed electrical engineer, my aspirations were high and I was ready to set the mobile radio system world on fire. A synergistic combination of my own zeal and aptitude (I earned my Ham license at age 16) with that of a seasoned engineer mentor...

Please Visit Empower RF's Website in Appreciation of Their Support

Empower RF Systems - RF CafeEmpower 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.

Science Theme Crossword Puzzle for January 24th

Science Theme Crossword Puzzle for January 24th, 2021 - RF CafeThis Science Theme crossword puzzle for January 24th contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword 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., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Electronics-Themed Comics

Electronics-Themed Comics, January 1951 Radio-Electronics - RF CafeThe January 1951 issue of Radio-Electronics magazine had a big collection of electronics-themed comics - five of them. All of them are pretty good, and you don't need to have been there during the early TV era to appreciate the humor. The comic from page 127 is a good first step in troubleshooting for today, and is usually at the top of the problem solving section of consumer gear throughout the electronic age. The page 126 comic is an oft-used gag for garage-related funnies. Although not directly related, it reminds me of how early wireless garage door openers had their antennas stretched underneath of the car...

RF Cafe Quiz: Gigabit μ−wave and mm−Wave Communications

RF Cafe Quiz #34: Multi-Gigabit Microwave and Millimeter-Wave Wireless Communications - RF CafeAll RF Cafe Quizzes make great fodder for 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 Multi-Gigabit Microwave and Millimeter-Wave Wireless Communications, by Jonathan Wells.

Microstrip Circuit and Material Characterization System

Microstrip Circuit and Material Characterization System - RF Cafe"Characterizing microstrip superconducting film at millimeter-wave frequencies is difficult without undergoing a complex thin film fabrication process. This characterization includes measuring the ohmic loss at a resolution of 10100 parts per million (ppm). Typically, characterizing microstrip superconducting film utilizes antenna-coupled bolometers as part of the superconducting film structure. Bolometers are components that measure incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance; however, this process is disadvantageous as embedded detectors, such as bolometers, make the superconducting film fabrication process more difficult. This process also requires various millimeter-wave components, further complicating film fabrication. Additionally, characterizing superconducting film..."

Bandwidth Requirements for Pulse-Type Transmissions

Bandwidth Requirements for Pulse-Type Transmissions, February 1945 QST - RF CafeIn 1945, when this article was published in QST magazine, radar was still in its infancy. Engineers were already aware of the need to shape pulse waveforms from experience with CW keying and the need to mitigate the effects of "chirping." A perfectly rectangular pulse in the time domain, as we learned in our signals and systems courses, creates a sin (x)/x response in the frequency domain. The Fourier transform shows that a perfectly square pulse in the time domain is the summation of an infinite number of odd harmonics of the fundamental (1st harmonic). The first few harmonics are audible to the CW copier as higher frequency "chirps." To reduce the annoyance (and wasted transmitted energy), time constants were added to the leading and trailing edges of the waveform to remove the higher frequencies, while leaving the pulse shape sufficiently rectangular to achieve its goal. The same type issue applies to radar pulses...

Tales from the Cube

Tales from the Cube - RF CafeHere's a trip down Memory (640 kB) Lane for those of us around during the early PC days, using MS−DOS. EDN magazine has been running their column "Tales from the Cube" (a take-off of the equally long ago "Tales from the Crypt" TV show) where readers submit sagas of (usually) troubleshooting experiences. Most often the problem is the result of an intermittent event or of human error (pronounced "stupidity"). This is a case of the latter. If you fondly recall the times when 256-color VGA CRT monitors, 3½" floppy disks, 20 MB hard drives, and an i80287 math coprocessor were to die for, when you were deemed a computer expert if you could write batch files, and half your computer's CPU power was not consumed by antivirus programs (no WWW, just Kermit for local net access), then you might like this "The Mysterious MS-DOS Reboot" anecdote by Robert Yankowitz. Enjoy!

Post Your Engineer & Technician Job Openings on RF Cafe for Free

Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

Thanks to Axiom Test Equipment for Continued Support!

Axiom Test Equipment - RF CafeAxiom Test Equipment allows you to rent or buy test equipment, repair test equipment, or sell or trade test equipment. They are committed to providing superior customer service and high quality electronic test equipment. Axiom offers customers several practical, efficient, and cost effective solutions for their projects' TE needs and is committed to providing superior customer service and high quality electronic test equipment. For anyone seeking a way to offload surplus or obsolete equipment, they offer a trade-in program or they will buy the equipment from you. Some vintage items are available fully calibrated. Please check out Axiom Test Equipment today!

Radio Lands the Plane

Radio Lands the Plane, August 1938 Radio News - RF CafeConsidering that only three-and-a-half decades had passed since the brothers Wright first flew their eponymous "Flyer" off the sands of Kitty Hawk, North Carolina, it is pretty impressive to think that by 1938 the majority of commercial air transport planes were under the able control of electromechanical apparatus(es?). Rudder, elevator, aileron, and throttle, driven by electrical servomechanisms rather than human hands and feet, responded to the signals to analog computers fed data from onboard barometer, accelerometer, level, and compass sensors, and from ground-based radio directional beams. That was for mostly straight and level flight from one fixed waypoint to another. An ability to program vectored flight paths came later. This "Radio Lands the Plane" article discusses progress being made in the realm of completely automated landings. As can be seen, the framework for modern instrument landings systems was being laid...

Withwave Intros 2.92 mm to SMPM Adapter Series (DC to 40 GHz)

Withwave Intros 2.92 mm to SMPM Adapter Series (DC to 40 GHz) - RF CafeWithwave's precision 2.92 mm to SMPM mm Adapter Series are designed based on precision microwave interconnection technologies. These adapter series are manufactured to precise microwave specifications and constructed with male and female gender on both sides. The precision microwave connector interfaces ensure an excellent microwave performance up to 40 GHz. VSWR is 1.2:1 (max), M-M, M-F, F-F, F-M interface combinations, passivated stainless steel body. Useful in laboratory and productions test setups, prototyping, and production interconnections...

Electronic Devices Printed Using Graphene Inkjet Process

Next-Gen Electronic Devices Printed Using Graphene-Based Inkjet Process - Airplanes and Rockets"A team at the University of Nottingham used graphene, a material with high electrical conductivity, in an ink-jet printing process to build up mesh together electronic structures that can perform functions such as converting light into electricity. Related: New 2D Materials Show Promise for Future Electronic Devices The approach demonstrates a new way to use the material for 3D printing processes as well as provides insight into the design of next-generation electronic devices, researchers said. Led by Professor Mark Fromhold, head of the university’s School of Physics and Astronomy, the team used quantum mechanical modeling to identify how electronics move through 2D-material layers..."

Microwaves Part II: Generation of Microwaves

Microwaves Part II: Generation of Microwaves, August 1945, Radio-Craft - RF CafeThe Barkhausen-Kurz (B-K) oscillator is credited as being the first high power microwave generator that exploited the electron transit time effect. It was developed in 1920 by German physicists Heinrich Georg Barkhausen and Karl Kurz. As this article's author points out, the vacuum tube and supporting circuits were difficult to produce and were not very well understood theoretically. Shortly thereafter, the magnetron and klystron tubes came along and dominated the high power microwave generation realm. Included in Part II of "Microwave - Generation of Microwaves" is a good, brief explanation of the operation of both B-K and magnetron circuits...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Triad RF Systems MPDevice microwave devices - RF Cafe
Windfreak Technologies Berkeley Nucleonics Model 855B Signal Generator - 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 typing 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:  AirplanesAndRockets.com


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

These Are Available for Free