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Homepage Archive - March 2019 (page 4)

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.

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See Page 1 | 2 | 3 | 4  of the March 2019 homepage archives.

Sunday 31

Engineering & Science Crossword Puzzle for March 31

RF Cafe Engineering & Science Crossword Puzzle March 31, 2019Since 2000, I have been creating custom technology-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been 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 ...

Friday 29

Industrial Electronics: Should We Sell to the Russians?

Industrial Electronics: Should We Sell to the Russians?, April 20, 1964 Electronics Magazine - RF CafeHere is an instructive look back at the near post World War II and Korean War timeframe when U.S. bureaucrats and industry titans were considering the pros and cons of selling our technology to foreign countries - especially to present and recent past sworn enemies. 1964, when this article appeared in Electronics magazine, was the Bay of Pigs era when the threat of nuclear war was on everybody's mind. In those days there were still company directors who would rather sacrifice potential profit in order to assure that their country would retain its technological leadership, its military superiority, and its national security. Others adopted the attitude that is the overwhelming rationale today - if we don't sell products and along with it the technological intelligence - then somebody else will. That philosophy slowly but surely ...

Custom MMIC Looking for a Senior MMIC Design Engineer

Custom MMIC Looking for a Senior MMIC Design Engineer - RF CafeCustom MMIC, a leading independent microwave and millimeter wave circuit design center, seeks an experienced Senior MMIC Design Engineer to join their design team. The candidate should have a strong background in high frequency integrated circuit design (especially above 5 GHz) using a variety of GaAs and GaN semiconductor processes including, but not limited to: MESFET, PHEMT, mHEMT, and HBT. The candidate must be able to handle all aspects of circuit design, from specification review to simulation, layout, and prototype testing. Experience in amplifiers (low noise, drive, power), mixers, switches, phase shifters, and/or attenuators is required. This position requires significant independent work with minimal supervision ...

Aircraft Detection Prior to the Invention of Radar (Acoustic Defense)

Aircraft Detection Prior to the Invention of Radar (Acoustic Defense) - RF CafeBeginning in the middle of the 1930s, engineering labs in the U.S. and Europe were experimenting with radar systems. Early radars did not have the slick plan position indicator (PPI) displays that modern systems use for plotting target movement for indication of azimuth (direction) and range (distance). Instead, oscilloscopes showed radar returns as amplitude blips along a time base that represented range. Azimuth was determined by where the operator pointed the antenna (rotating versions came later). Since radar cross section stealth technology had not been invented yet, the amplitude of the signal was useful a measure of the size of the target. Prior to the invention of radar (RAdio Detection And Ranging), other means were needed to detect ...

Invisible Women Programmed America's 1st Electronic Computer

Invisible Women Programmed America's First Electronic Computer - RF CafeThe history of AI is often told as the story of machines getting smarter over time. What's lost is the human element in the narrative, how intelligent machines are designed, trained, and powered by human minds and bodies. In this six-part series, we explore that human history of AI - how innovators, thinkers, workers, and sometimes hucksters have created algorithms that can replicate human thought and behavior (or at least appear to). While it can be exciting to be swept up by the idea of super-intelligent computers that have no need for human input, the true history of smart machines shows that our AI is only as good as we are. Part 2: The Invisible Woman Programmers of ENIAC ...

R&D Framework Devises On-Glass Antennas

R&D Framework Devises On-Glass Antennas - RF Cafe"By completing the anechoic chambers in Europe, AGC has established a framework for accelerating the research and development of antennas to meet demand for 'connected' cars in the age of IoT and supporting automobile development by its customers on a global scale. With the completion of this R&D facility, AGC has established a tri-polar R&D framework for automotive on-glass antennas in Japan, the United States and Europe for the first time in the glass industry. In a future mobility society, cars will be equipped with devices such as cameras, LiDARs and sensors. Cars will need to be both connected to each other and have communicative functionality that delivers V2X ..."

VidaRF: Passive RF & Microwave Components

vidaRF passive RF & microwave components - RF CafeAt 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!" ...

Thursday 28

Readers Comment: Radar Beeps

Readers Comment: Radar Beeps, April 20, 1964 Electronics Magazine - RF CafeOops, I forgot to post the piece after posting back in September the "Radar Adds Beep to Home Sets" article from the February 28, 1964 issue of Electronics magazine. The April 20th issue published a reader response to the problem of the U.S. Air Force recently commissioned AN/FPS-24 long range "superpower radar" in some of the country's major seaboard and northern cities. Designed to watch for ICBM's and intruding long-range aircraft from the U.S.S.R., it operated in the 214 to 236 MHz band (VHF) at a 7.5 megawatt peak power output. Immediately there were massive reports from surrounding homeowners and businesses about the annoying beeps being heard on radio and television every time the rotating antenna pointed in their direction ...

App Note: Theory and Method to Characterize the IP2 of Wideband Amplifiers

Theory and Method to Characterize the IP2 of Wideband Amplifiers - RF CafeThe good folks at Custom MMIC just posted a new application note titled, "Theory and Method to Characterize the IP2 of Wideband Amplifiers." It begins, "We are excited to release our new Application Note that describes the theory and method used by Custom MMIC to characterize the second order intercept point (IP2) of its wideband amplifiers. We offer a large selection of wideband amplifiers as standard products with superior IP2 levels. Distortion in amplifiers can take many different forms. One type of distortion occurs when the output signal level gets large and approaches the 1 dB compression point of the amplifier. In this case, the output waveform is compressed or even clipped, and this action generates unwanted harmonics ..."

Capacitor Circuit Quiz

Capacitor Circuit Quiz, June 1968 Popular Electronics - RF CafeHere is a nice quiz on calculating total equivalent capacitance for circuits containing various combination of series, parallel, and series-parallel connections. To help in calculation, all of the individual capacitor values are the same. Many of them you can probably solve in your head, especially if you mentally rearrange the circuit into a more readily recognizable configuration. For instance, circuit #1 can be redrawn having two parallel branches across the source. One branch has just a single capacitor while the other has two parallel capacitors in series with one capacitor. The equation is then C + (2C2/3C) = C + 2/3C = 5/3C. For C = 6 pF, Ctotal = 5/3*6 pF = 10 pF ...

Smiths Interconnect Seeking a Senior RF Engineer

Smiths Interconnect Seeking a Senior RF Engineer - RF CafeSmiths Interconnect currently has a job opportunity for a Senior RF Engineer. Smiths is always looking for curious minds. For new colleagues who want responsibility and relish a challenge. Responsible for all phases of product development from conception through production of RF / microwave / mm-wave components (e.g. couplers, power dividers, LNAs, mixers, PAs, switches, phase shifters, attenuators, oscillators, antennas, ferrite devices, etc.) and subsystems (e.g. transceivers, frequency converters, RADAR front-ends, radiometer front-ends, LO sources, frequency synthesizers, switch matrices, arrays) built up from these components. Other possible duties include bid & proposal ...

Army to Build Ground-Penetrating Radar Drones

Army to Build Ground-Penetrating Radar Drones - RF Cafe"The Army's Engineer Research and Development Center wants to put radar systems that identify environmental phenomena on unmanned aerial and ground vehicles so they can be used to survey previously inaccessible locations and cover more territory from the air. Currently, ground-penetrating radar systems are large arrays mounted on the front of military vehicles to detect improvised explosive devices. Smaller commercial versions exist as well. Ground penetrating radar has non-military uses as well; it is currently being used to find cracks and corrosion in pavement. The Robotics Assisted Bridge Inspection Tool ..."

RF Superstore: Supplier of RF & Microwave Components

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 $99. We're leading the way again!

Wednesday 27

Microwave Plumbing Replaces Circuitry

Microwave Plumbing Replaces Circuitry, September 1948 Radio & Television News - RF CafeHere is a great treatise on waveguide theory put in layman's language. Although published in a 1948 issue of Radio & Television News at a time when microwave frequencies were just coming into common use, the language and descriptive drawings are similar to what you will find in modern textbooks. Waveguide is not practical for use at lower frequencies because the physical dimensions are prohibitively large. For instance, for the FM radio band (88-108 MHz), waveguide width for a TE10 cutoff frequency at 88 MHz is around 67.5 inches. According to Wikipedia, the first waveguide was proposed by J. J. Thomson in 1893 and experimentally verified by Oliver Lodge in 1894 ...

World's Longest Flexible PCB

World's Longest Flexible PCB - RF CafeThis could easily by a publicity scheme by PCB maker Trackwise Designs, of Tewkesbury, UK, but it is not. "Trackwise has shipped a 26-metre long multilayer flexible printed circuit (FPC), believed to be the longest ever produced, for distributing power and control signals across the wings of a solar-powered, unmanned aerial vehicle (UAV). The circuit is one of over fifty supplied by Trackwise into this vehicle. The entire interconnect system (power and signal) of the vehicle is made of FPCs representing an estimated total systems weight saving of 60% over traditional wire harness. This will enable the UAV, which is being manufactured in the U.S., to achieve higher payload and/or improved speed and range ..."

Non-Destructive Transistor Tester

Non-Destructive Transistor Tester, March 1971 Popular Electronics - RF CafeIn the days before just about every multimeter had a built-in diode and transistor tester, there was not much - if anything - available for the hobbyist. Some of the vacuum tube test sets, like my 1961 vintage B&K Dyna-Quik Model 650, surprisingly included diode and transistor test sockets. This article for a "non-destructive" type - as opposed to the popular "destructive" type - homebuilt transistor tester appeared in a 1971 issue of Popular Electronics magazine. It can identify PNP vs. NPN, measure DC gain, and measure leakage current. The tester will verify diode integrity as well. There's also a bonus "Parts Talk" comic on the page at no extra cost ...

NFC Technology for Tire Identification and Diagnostics in Auto Apps

NFC Technology for Tire Identification and Diagnostics in Auto Apps - RF Cafe"The University of Luxembourg and the Goodyear Innovation Center in Luxembourg have launched a new research project to study the use of Near-Field Communication (NFC) in automotive safety systems. The 4-year research project has the potential to initiate major innovations in the automotive sector. It is funded by the Luxembourg National Research Fund (FNR) and Goodyear. Near-field communication is poised to fundamentally change the automotive sector. It is a form of short-range wireless communication that relies on electric and magnetic fields generated around a transmitting antenna. This communication technology is now being explored for automotive applications ..."

Reactel: RF & Microwave Filters of All Types

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

Tuesday 26

Electronics Newsletter: UK to Get NTSC Color TV

Electronics Newsletter, March 6, 1964 Electronics Magazine - RF CafeThis issue of Electronics magazine's Newsletter page contained, as usual, a number of topics, but the two that caught my eye were on the BBC (British Broadcasting Corporation) lobbying their International Radio Consultative Committee (CCIR) to consider adopting America's NTSC standard for color television. The two competing standards were France's SECAM (Sequential Color with Memory) and Germany's PAL (Phase Alternating Line). The main difference between NTSC and the other two standards is NTSC used 525 scan lines whereas the other two used 625 scan lines (different frame rates, too). All three were designed to be backward-compatible with the existing black & white (B&W, or "monocolor" in Europe) television broadcast scheme ...

Thanks to Copper Mountain Technologies for Continued Support

Copper Mountain TechnologiesCopper Mountain Technologies develops innovative and robust RF test and measurement solutions for engineers all over the world. Copper Mountain's extensive line of unique form factor Vector Network Analyzers include an RF measurement module and a software application which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware via USB interface. The result is a lower cost, faster, more effective test process that fits into the modern workspace in lab, production, field and secure testing environments ...

Temperature Chamber Choices

Temperature Chamber Choices (TotalTemp technologies) - RF CafeThe good folks at TotalTemp Technologies, experts in the realm of thermal testing methods and equipment, has published a new Blog topic titled, "Temperature Chamber Choices." Per TotalTemp's post: "Thermal testing testing of products can't be ignored. Knowing your product stands up to the harshest environments it will be exposed to over the life of the product provides proof of the design and verified quality. With TotalTemp Temperature Chambers and Thermal Platforms you can most effectively run thermal tests for burn-in or design/production verification. Products meant for consumers have to be tested, but it's safe to say, products going into space need far more rigorous verification. Life tests or inappropriate tests can go too far, thus shortening the life so it is important ..."

A Few Electronics-Themed Comics

Electronics Themed Comics, September 1945 & December 1947 Radio-Craft - RF CafeHere are a few more electronics-themed comics from magazines of the days of yore - in this case Radio-Craft. The country's fascination with all things electronic is apparent - including robots, which should have taken over the world by now. It is rare to find a comic in a technical or hobby magazine these days. I don't know why that is. Enjoy ...

Argonne National Laboratory Exascale Supercomputer by 2021

Argonne National Laboratory Exascale Supercomputer by 2021 - RF Cafe"Intel Corporation and the U.S. Department of Energy (DOE) will build the first supercomputer with a performance of one exaFLOP in the U.S. The system being developed at DOE's Argonne National Laboratory in Chicago, named 'Aurora,' will be used to dramatically advance scientific research and discovery. The contract is valued at over $500M and will be delivered to Argonne National Laboratory by Intel and sub-contractor Cray Computing in 2021. The Aurora systems' exaFLOP of performance - equal to a 'quintillion' floating point computations per second - combined with an ability to handle both traditional high performance computing (HPC) and artificial intelligence ..."

Electro-Photonics Offering RF & Microwave Products

Electro-PhotonicsElectro-Photonics is a global supplier of RF & Microwave components. Their products include SMT hybrid and directional couplers, wire bondable passive components, mounting tabs, filters, transmission lines, and very useful test boards for evaluating components (spiral inductors, single-layer capacitors). The Electro-Photonics team can support your small R&D design requirements with RF & Microwave test fixtures and save you valuable design and characterization time. Please take a moment to visit Electro-Photonics' website and see how your project might benefit ...

Monday 25

Leslie Effect Simulator

Leslie Effect Simulator, March 1971 Popular Electronics - RF CafeAn RF Cafe visitor wrote to ask that I scan and post this article on the Leslie Effect Simulator, which appeared in a 1965 issue of Popular Electronics. "What the heck is the Leslie effect?" you are probably asking, as did I. Basically, it is a mechanism for artificially creating the "wobbulating" effect of a pipe organ in a large echoing environment. Inventor Donald Leslie worked for the Hammond organ company and developed an electromechanical contraption that rotated a baffle in front of speakers to create the effect. Commercial electronic Leslie Effect products were sold back in the 1960s and 1970s when high fidelity (hifi) stereo equipment was the "in" thing, like computers were in the 1990s and cellphones are now. There were a lot of electronics hobbyists that loved to build projects printed in magazines ...

Time Domain Scans and Stepped Frequency Scans in EMI Test Receivers

Rohde & Schwarz Time Domain Scans - RF CafeRohde & Schwarz has published an application note titled, "Comparison of Time Domain Scans and Stepped Frequency Scans in EMI Test Receivers." For EMI testing, the use of Time Domain Scan greatly reduces measurement time without compromising accuracy. The paper takes a critical look at the technology and its advantages. It compares measurement speed and level measurement accuracy of a conventional stepped frequency scan versus an advanced FFT-based time domain scan, learn the principles of overlapping in the time and frequency domain, and discuss how to choose the right measurement tool for CISPR and MIL-STD testing. During product development, the frequency spectra of disturbances need to be measured frequently and compared ...

Find a Signal's Bandwidth from Its Harmonics

Find a Signal's Bandwidth from Its Harmonics - RF CafeBob Witte has an interesting article on the website titled, "Find a Signal's Bandwidth from Its Harmonics." It begins, "There are several ways to evaluate the bandwidth of a signal in the time domain and frequency domain. Previously we looked at the classic relationship of rise time (tr) and bandwidth (f3db), captured by this equation: Eric Bogatin also provided Rule of Thumb #2 for estimating the signal bandwidth from the clock frequency. Eric emphasizes that you really should use the rise time to calculate signal bandwidth, but you can get a reasonable answer quickly using this Rule of Thumb: In Eric's article, he makes a key ..."

How Far Can You Go in Electronics Without a Degree?

How Far Can You Go in Electronics Without a Degree?, September 1957 Popular Electronics - RF CafeThis story reads like an infomercial for IBM, which it probably is. Of course infomercials had not been invented by 1957, so IBM was ahead of its time. The answer to the article's title, "How Far Can You Go in Electronics Without a Degree?" was the same 55 years ago as it is today: As far as your intellect and ambition will take you. Back then, as with today, few people could rise to the level of design engineer without a college degree. However, there are many aspects of electronics that requires no formal education at all if you possess the requisite skills. I never have bought into the feel-good lie about anyone being able to be whatever he or she wants to be. Some people simply cannot achieve the mastery necessary to do a particular job ...

Quantum Radio Can Detect Universe's Weakest Quantum Signals

Quantum Radio Detects Universe's Weakest Quantum Signals - RF Cafe"A new 'quantum radio' has been demonstrated that can detect the weakest signals allowable under quantum mechanics. Researchers have demonstrated how to detect the weakest radio signals allowed under quantum mechanics, opening the door to advances in radio astronomy and medicine, and physics. The Quanta in the Noise Researchers at Delft University of Technology (DUT) in the Netherlands have built a quantum circuit that allows them to listen to the faintest signal allowable under quantum mechanics, leading to possible advances in radio astronomy, medicine, and attempts to reconcile quantum mechanics and relativity ..."

TotalTemp Technologies: Thermal Platforms for −100°C to +200°C

TotalTemp Technologies - RF CafeTotalTemp Technologies has more than 40 years of combined experience providing thermal platforms. Thermal Platforms are available to provide temperatures between −100°C and +200°C for cryogenic cooling, recirculating circulating coolers, temperature chambers and temperature controllers, thermal range safety controllers, space simulation chambers, hybrid benchtop chambers, custom systems and platforms. Manual and automated configurations for laboratory and production environments ...

Sunday 24

Engineering & Science Crossword Puzzle for March 24

RF Cafe Engineering & Science Crossword Puzzle March 24, 2019Since 2000, I have been creating custom technology-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been 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, if you don't already know, might surprise you ...

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    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...

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