Today in Science History -
 A momentous development that changed the field of radio communications warranted merely a half-page announcement in 1935 when frequency modulation inventor Edwin Armstrong had his article published in Radio-Craft magazine. It indisputably changed the world while causing poor Mr. Armstrong much grief in defending his right to the invention. Spread spectrum modulation / demodulation would be the next big communications advance that began with the frequency hopping (FHSS) scheme dreamed up by Hollywood actress Hedy Lamarr and pianist Antheil George during World War II. Direct sequence spread spectrum (DSSS) followed in the digital age, and since then I do not know of any fundamentally new communications technology in that time...
 RF 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 (of course a gratuity will be graciously accepted). 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...
 Precision ruggedized VNA cables from ConductRF offer RF engineers great alternatives to costly OEM cables that are now past their best days, and now you can reach out to Digi-Key for a quick and easy replacement. We have standards for applications at 18 GHz, 27 GHz, 40 GHz, 50 GHz & 70 GHz. Our torque resistant connector heads and phase stable constructions ensure great performance for many tests to come. ConductRF VNA series provides customers with reliable ruggedized solutions for lab and production vector network analyzer testing. We Know, Results Count...
 "Engineers from the ESA and Sweden’s Royal Institute of Technology (KTH), have designed a novel 'water drop' antenna lens for directing radio wave signals. In the same way that optical lenses focus light, waveguide lenses serve to direct electromagnetic radio wave energy in a given direction. This can be used to minimize energy loss when sending out a radar or a communication signal. Traditional waveguide lenses have complex electrically-sensitive dielectric material to restrict electromagnetic signals as desired. But once the top plate of this water drop waveguide lens has been added on, it comes down purely to its curved shape for directing signals through it. The inventors of this new lens design, which received an ESA Technical Improvement award in February 2017, likes to call it..."
 Keysight Technologies' Matt Ozalas and Thomas Winslow will present a free webinar entitled, "Designing for Stability in High Frequency Circuits," on January 29th at 1:00 pm ET. "High-frequency circuit designers often struggle with stability. Learn techniques to identify and solve stability problems in the design phase before they become headaches in the lab. Classical techniques will be discussed, and a new technique will be introduced using a bidirectional impedance probe in PathWave Advanced Design System (ADS) called the 'Winslow Probe.' Techniques to identify and solve stability problems in the design phase Basic design examples to compare various stability techniques Realistic examples of a successful high frequency power amplifier design..."
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 One of the photos in this 1958 Radio & TV News magazine article on the Jodrell Bank radio telescope shows what appears to be the largest multi-conductor cable connector I have ever seen. It looks like a early Photoshopping of a DB−9 connector with a heavy metal back shell. The cable bundle is three to four inches in diameter. Rather than use slip rings to transfer the control, data, and power signals from the base to the steerable 250-foot diameter parabolic dish of the Jodrell Bank radio telescope (now called the Lovell telescope), a single massive cable does the job. The science of radio astronomy was barely three decades old at the time it was built. It was in 1931 that Karl Jansky first determined that radio signals were coming from our Milky Way galaxy. He eventually ended up working for Bell Labs in Homdel, New Jersey, where he built a radio telescope to investigate background noise in the 10-20 meter wavelength band, where Bell planned to use its microwave relay system...
 This 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...
 Mr. Mark Misfud, chairman of the Asia Pacific Electromagnetic Compatibility Symposium 2020 (APEMC 2020) wrote asking to have the event announced. It will be held May 19-22 at the Hilton Hotel, in Sydney, Australia. Per the website, "Modern Society is increasingly becoming more connected and the technology that is enabling this to happen is operating in a complex and hostile electromagnetic environment. As such knowledge and practical experience in EMC design, mitigation and testing is increasingly in demand. Developing technology such as 5G and autonomous vehicles present exciting possibilities but also provide challenges to those in the field due to the dynamic nature of the electromagnetic environment that the technology operates in. For the uninitiated EMC is black magic but those in the industry know it is application of common sense principles based on established electromagnetic theory and implementation of good design..."
 "2-D semiconductors could have very useful applications, particularly as channel materials for low-power transistors. These materials display very high mobility at extreme thicknesses, which makes them particularly promising alternatives to silicon in the fabrication of electronics. Despite their advantages, implementing these materials in transistors has so far proved to be challenging. In fact, 2-D semiconductors are of a dangling-bond-free nature; thus, it is notoriously difficult to deposit ultrathin high-κ gate dielectrics (i.e., substances with dielectric properties or insulators) on the materials via atomic layer deposition (ALD), often resulting in discontinuous films..."
 Mya Rae Nelson has an excellent article in the current issue of Fine Woodworking magazine entitled, "The Science Behind Epoxies." I was surprised to read that epoxy has only been around since the 1940s, so when I first used it in the early 1970s, it was only a three decade old technology. As with cellphones, now that we have epoxy, how did we ever get along without it? Ms. Nelson uses layman terms to describe the molecular makeup of both the epoxy resin and the hardener, and describes how the bonds between the resin atoms are broken then reestablished with the insertion of hardener atoms into the matrix. If you attended classes for and understood the basics of chemistry, that will help with understanding the technical side of epoxy curing and strength, but even without the nerd knowledge you will still gain a better understanding of how this indispensible modeler's brew works.
 Alliance 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. Please visit Allied Test Equipment today to see how they can help your project.
 Before there was the annual International Microwave Symposium (IMS) trade show, the Institute of Electrical and Electronics Engineers' (IEEE) Microwave Theory and Techniques Society (MTT-S) hosted the show, which was widely known as the MTT-S show. Before that, the event went by a variety of names, including "Intercon," (International Convention and Exposition) as reported in this 1972 issue of Popular Electronics magazine. For the first few decades since its inception in the 1950s, New York City was the venue, often in a hotel. As with tides and solar cycles, enthusiasm and attendance waned and ebbed over the years. 1972 was one of the low years. Per the story, about half the number of people were there compared to two years prior. I could not locate a chart of attendance numbers over the years, nor the numbers to generate my own chart...
 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.
 One day in late spring of 1973 I found myself walking around the gymnasium of Annapolis Junior High School (AJHS) trying to decide which courses I would prefer upon beginning tenth grade the following fall. It was one of the final days of ninth grade, which had been by far my least happy year in school. Living in Mayo, Maryland, I and my fellow neighborhood ninth graders should have attended Southern Senior High School (SSHS) in Harwood, Maryland, where our predecessors had gone for ninth grade, but overcrowding caused the Anne Arundel School Board wizards to decide that for at least that year, we would remain at AJHS for another term. Historically, kids from my area went to AJHS only for seventh and eighth grades and then switched to SSHS. Annapolis, being the capital city of Maryland, was significantly more urban than the rural areas to which SSHS type people were accustomed. The clientele was much more aggressive in the big city. Sure, we had our "red neck greaser" rowdies in the southern part of the county, but at least their parents would whip them if they got caught getting into trouble...
 "Researchers at Imec have demonstrated what they believe to be the first functional GaAs-based heterojunction bipolar transistor (HBT) devices on 300 mm Si, and CMOS-compatible GaN-based devices on 200 mm Si for mm-wave applications, showing cut off frequencies in the 40/50 GHz region. In wireless communication, with 5G as the next generation, there is a push towards higher operating frequencies, moving from the congested sub-6GHz bands towards mm-wave bands (and beyond). The introduction of these mm-wave bands has a significant impact on the overall 5G network infrastructure and the mobile devices. For mobile services and Fixed Wireless Access (FWA), this translates into increasingly complex front-end modules..."
 Copper Mountain Technologies (CMT) has produced a series of videos to help users of its diverse line of vector network analyzers (VNAs) get the most out of their extensive capabilities. Proprietary features in both hardware and software supplies VNAs designed by CMT with capabilities far beyond similar equipment by other companies. This video entitled, "Automatic Calibration Module Confidence Check," is one of a series of videos that can be found on the Copper Mountain Technologies website. "How many times have you completed a series of measurements to find them tainted by a bad cable...
 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...
 Imagine reading an article from a 1958 magazine that references the schematic for a specific radio manufactured in Germany, and then being able to download a copy of it for free on the Internet. Such is the case with this Mac's Radio Service Shop story entitled, "Was Ist Los?" Mac is describing to his sidekick Barney the difficulty in troubleshooting and repairing a Metz Transformatoren: Babyphon 56 that a serviceman had purchased while stationed overseas. The diagram is of course in German, which requires Mac to pull out a language translation dictionary. The problem was that many words unique to technical jargon were not in it. Additionally, units of measure for the capacitors and inductors were not like U.S. units. Mac noted that many capacitor values were labeled with units of "u," "n," and "p," for "micro," nano," and "pico." He mentions the "micro" prefix for the letter "u," but never calls the "n" and "p" by the now-standard terms...
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