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RF Cascade Workbook 2018 (GS) - RF Cafe
Homepage Archive - February 2019 (page 3)

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

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


See Page 1 | 2 | 3 | 4  of the February 2019 homepage archives.
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Friday 22

Extra-Terrestrial Relays, by Arthur C. Clarke

Extra-Terrestrial Relays, by Arthur C. Clarke - RF CafeAsk and ye shall receive... at least sometimes. I posted a request for an article by science fiction writer Arthur C. Clarke, of 2001: A Space Odyssey fame, describing a geostationary satellite system that was published in the October 1945 edition of Wireless World magazine. Thanks to RF Cafe visitor Terry W., from the great state of Oklahoma, it is now available for everyone to enjoy. Clarke was not just a sci-fi writer, but also an educated visionary and card-carrying member of the British Interplanetary Society, who proposed many technological solutions to issues of his day. In this instance, the challenge was developing an efficient means to distribute TV signals across Europe and the world. Clarke's calculations for the necessary number of repeater towers proved that concept impractical, so he proposed using modified surplus German V2 rockets to launch Earth-orbiting "artificial satellites," powered ...

Webinar: Deep Learning for RF Systems

Webinar: Deep Learning for RF Systems - RF CafeAnalog Devices and Arrow Electronics will be presenting a free webinar on March 21st titled, "Deep Learning for Radio Frequency Systems." Deep learning within RF shows promise for dealing with a congested spectrum by enhancing reliability and simplifying the task of building wireless systems. This webinar will discuss a software defined radio that can perform real-time DSP and deep learning with an NVIDIA GPU and an Analog Devices front end. We'll discuss system performance, training of RF data, software used to deploy algorithms, and take a deep dive into one application. Attendees will learn: Applications of deep learning for systems and signals ...

R&S White Paper: An Introduction to EMC Amplifiers

Rohde & Schwarz White Paper: An Introduction to EMC Amplifiers - RF CafeRohde & Schwarz USA (R&S USA) has published a white paper titled, "An Introduction to EMC Amplifiers." This white paper describes not only the basics of EMC amplifiers, but also intricacies, discusses parameters and characteristics that have the greatest influence on amplifier performance. It provides a technical overview of EMC amplifiers as well as a practical discussion of how amplifier class, compression points, VSWR, foldback, etc. impact amplifier performance in real-world scenarios. Broadband amplifiers are necessary for generating the field strengths required for most EMC radiated immunity tests. This whitepaper provides a brief overview of the role of amplifiers in EMC testing as well as a discussion of the parameters and characteristics which have the greatest influence on amplifier performance ...

Cheap Flexible Sensor Detects Magnetic Fields down to 20 nT

Cheap Flexible Sensor Detects Magnetic Fields down to 20 nT - RF Cafe"A team of researchers from Germany and Argentina have devised an ultra-thin planar Hall effect (PHE) sensor capable of detecting very faint magnetic fields even when flexed or wrapped around a wire. In a paper titled "Highly compliant planar Hall effect sensor with sub 200 nT sensitivity" published in Nature's npj Flexible Electronics journal, the researchers describe a very simple fabrication process, whereby asymmetrical Permalloy (Py) Hall crosses just 20 nm thick are patterned on 6 µm-thick PET foils before being magnetized through multiple magnetic field sweeps (between ±3 mT) ..."

QuinStar Technology: mm-Wave Active & Passive Components

QuinStar Technology mm-Wave Products - RF CafeQuinStar Technology designs and manufactures mm-wave products for communication, scientific, and test applications along with providing microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, Oscillators, Switches, Attenuators, Circulators, Isolators, Filters, Waveguide, Antennas, Phase Shifters, Transceivers, Mixers, Detectors. QuinStar specializes in cryogenic amplifiers, circulators, and isolators. Please visit QuinStar today to see how they can help your project ...

Thursday 21

Kynar Pennsalt Vinylidene Fluoride Resin Advertisement

Kynar Pennsalt Vinylidene Fluoride Resin Advertisement, April 6, 1964 Electronics Magazine - RF CafeDid you know that at least originally the term "Wire-Wrap" was - and maybe still a - registered trademark of Gardner-Denver Company? Kynar insulation, whose full name is Kynar polyvinylidene fluoride (PVDF) resin, is most likely a familiar type of insulation due to its widespread use on wire-wrap wire. It had very recently been introduced to the electronics world when this advertisement appeared in a 1964 issue of Electronics magazine. The contemporary name used by its manufacturer, Arkema, is Kynar500®, and the coating's use has expanded well beyond the electronics industry into architectural and mechanical coatings. I did a LOT of manual wire-wrapping on Mil-Spec equipment while working as a technician at Westinghouse Oceanic Division ...

HF Dipole Antennas for Amateur Radio

HF Dipole Antennas for Amateur Radio - RF CafeARRL's HF Dipole Antennas for Amateur Radio, just released a few days ago is a collection of 20 HF dipole antenna designs published in QST, ARRL's membership journal, between 2000 and 2017. It includes innovative antenna projects for single-band and multiband antennas, as well as antennas for portable applications. Some of the featured antennas are: "An Easy-to-Make Three-Band Dipole for ARRL Field Day," "A Field-Portable Multi-Band Rotatable Dipole Antenna," "A Small, Portable Dipole for Field Use A Portable Twin-Lead 20-Meter Dipole," "The NJQRP Squirt Multiband Antennas," "A Shortened 60 Meter Dipole That Also Covers 15 Meters," "A Compact Multiband Dipole," "A Folded Skeleton Sleeve Dipole for 40 and 20 Meters ..."

How to Use Radio Propagation Predictions

How to Use Radio Propagation Predictions, December 1947 Radio-Craft - RF CafeShort wave radio was a boon to both professional and amateur radio operators because of its ability to be received over longer distances using significantly lower transmitter power. The problem was (and still is) that short wave bands typically suffer from atmospheric ionization effects that vary depending on time of day, local weather, solar activity, pollution, and other phenomena. Long wave's advantage was that although it required higher power and longer antennas, it was (and is) extremely reliable. For other than the most critical applications, idiosyncrasies of short wave communications were accepted as the price of more convenient and lower cost operation. Widespread adoption of short wave communications brought extensive studies and characterization of atmospheric influences in particular frequency bands. Discovery of distinct 'F' layers (regions) in the ionosphere and their effects on radio transmission has allowed ...

Free Engineering Magazines for February 2019

Engineering White Papers & Books, February 2019 - RF CafeWhitepapers, pamphlets, books, magazines, and chapter examples listed here are a small sample of a lot of new items that are offered for FREE through TradePub. The publishers make them available to qualifying people as a promotional campaign for their full line of offerings. Whitepaper topics include careers, manufacturing, and engineering, while magazine titles include Microwave Engineering Europe, Electronic Design, and Microwave Product Digest. Note: I earn a few pennies (literally) when you download one of these or the many other pubs available, so please help yourself ...

Anatech Electronics February 2019 Newsletter

Anatech Electronics February 2019 Newsletter - RF CafeSam Benzacar, of RF and microwave filter company Anatech Electronics, has written as part of his February newsletter this piece titled, "'Mysterious' Cuban U.S. Embassy Weapon: It Wasn't Crickets." Sam keeps abreast of all the latest news in the wireless world, which is not unexpected given his company's long-time involvement in helping others make their products play well together in an increasingly crowded electromagnetic spectrum - both licensed and unlicensed. Beginning in late 2016, news reports told how many U.S. and Canadian embassy staffers and their families told of hearing strange sounds in their heads and experiencing nausea and headaches. I read many of them. Of course no conclusive evidence as to the source has ever been discovered since officials of the western hemisphere's only Communist nation (Cuba) allows ...

QuinStar Technology: mm-Wave Active & Passive Components

QuinStar Technology mm-Wave Products - RF CafeQuinStar Technology designs and manufactures mm-wave products for communication, scientific, and test applications along with providing microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, Oscillators, Switches, Attenuators, Circulators, Isolators, Filters, Waveguide, Antennas, Phase Shifters, Transceivers, Mixers, Detectors. QuinStar specializes in cryogenic amplifiers, circulators, and isolators. Please visit QuinStar today to see how they can help your project ...

Wednesday 20

Are You Thinking About Producing a Webinar?

How to Become a Superstar Webinar Presenter - RF CafeWebinar presentations have become a huge part of ongoing training for engineers and managers - both by attending and conducting them. Your opportunity for becoming well-known in the industry can be greatly enhanced with an effective, attention-grabbing production as the star of a webinar (of course a bad performance can sink you just as easily). Register for your free OnDemand webcast now titled, "How to Become a Superstar Webinar Presenter." The last thing you want to hear is that your presenter was dull and people weren't engaged. A bored audience means low viewing time, low content retention, and, sometimes, total brand rejection. Don't let that happen to you! In this on-demand webinar, you'll learn how to find great webinar talent and best practices to make your existing presenters more engaging and presentations more fun ...

Magnetoresistance: Better than Hall-Effect Multipliers

Magnetoresistance: Better than Hall-Effect Multipliers, April 6, 1964 Electronics Magazine - RF CafeI'm having a hard time writing this with my eyes rolled back in my head. The last time I experienced this level of overwhelmedness was probably the third or fourth week of my feedback and control class at UVM. Even though electricity and magnetism shares many complimentary and parallel concepts, for some reason thinking in terms of magnetics when describing amplifiers, mixers, modulators, etc., has always caused brain freeze. Maybe it has to do with an ingrained bias due to my earliest dealings with circuits being from a technician background before earning an engineering degree. The equations of electric fields and magnetic fields are very similar so that helps lower the barrier a bit. An engineer I worked with once had the uncanny ability to comprehend time domain waveforms in the frequency domain, and vice versa, when viewing an o-scope or spectrum analyzer display. Sure, simple things like sine waves or square waves can be recognized by most people who have been in the field for a couple years, but this guy's ability ...

Withwave Intros 1.85 mm Vertical Launch Connectors

Withwave Intros 1.85 mm Vertical Launch Connectors - RF CafeWithwave's vertical launch 1.85 mm connectors are specially designed for solderless vertical PCB launch on test & measurement board. These connectors have excellent electrical transition performance up to 67 GHz as well as reduce installation time by eliminating soldering. It is the best solution available for easy use in test & measurement boards, high speed digital test boards. We solve your performance and cost problems ...

Current Flow: + to − Or − to +?

Electromagnetism and Magnetic Circuits Current Flow Convention - RF CafeThis chapter from the 1949 edition of the U.S. Navy's Electrician's Mate 3 course (NAVPERS 10548) requires an important clarification. Current flow in this article is defined as going from negative to positive, which is opposite of today's convention. Per the text: "Modern experiments have shown that a current of electricity is really a flow of electrons, and the direction of flow is from negative to positive." Beginning sometime in the 1960s, concurrent with the great amount of research being done in semiconductor electronics, the convention of positive-to-negative current flow was adopted, defined as the direction of positive charge carriers (holes). The negative-to-positive convention is defined based on the direction of negative charge carrier (electron) flow. I personally never understood the crisis that retaining the electron flow convention would have caused, but higher authorities decreed it to be done. We have gone from + to − current flow ...

NI AWR App Note Features Network Synthesis for Matching-Circuit Design

App Note Features NI AWR Software Network Synthesis for Matching-Circuit Design - RF CafeA new application note titled "Network Synthesis Wizard Automates Interactive Matching-Circuit Design" features the network synthesis wizard in NI AWR software that automates interactive matching-circuit design, thus reducing design time. Network synthesis is helpful at the earliest stages of a design to help determine reasonable performance targets based on device performance limits, device sizing (decisions on active device periphery), part selection for discrete packaged transistors and other early design decisions. Available as a free download now ...

Tuesday 19

The Transistor in Industry

The Transistor in Industry, May 1956 Radio & Television News - RF CafeIf you want to know what was really going on at some point in the past, there is usually nothing more reliable than reading a print story or advertisement from the era. That way you're getting the news "straight from the horse's mouth," so to speak, rather than being interpreted or filtered by some unassociated source. This report on "The Transistor in Industry" was written in 1956 by Mr. Frank Durat, a product manager at Raytheon, at a time when transistors were first making inroads for replacing the venerable vacuum tube (valve) which had launched and propelled the electronics industry since 1908 when Lee de Forest introduced the triode Audion amplifier. Germanium and silicon were the semiconductor base crystals du jour, and achieving the requisite purity was a primary concern for advancing the state of the art for higher frequencies, power handling, and circuit density (for integrated circuits) ...

Guerrilla RF's Automotive-Qualified Ultra-LNA

Guerrilla RF's Automotive-Qualified Ultra-LNA for SDARS, Compensator and GPS Applications - RF CafeGuerrilla RF, a leading provider of high performance MMICs, today introduces GRF2073-W, a new addition to the company's growing list of AEC-Q100 automotive-qualified amplifiers. This ultra-low noise amplifier is targeted at high-volume applications, with first-stage satellite radio LNAs and GPS modules being prime examples. It is offered in an industry-standard, ultra-small 2.0 x 2.0 mm DFN-8 package thus sharing a common pin out with other infrastructure-class devices from Guerrilla RF. "Guerrilla RF is proud to offer this new amplifier for automotive applications which addresses an industry need for a cost-effective, first-stage LNA delivering outstanding RF performance with low power ...

What's Wrong with This Picture?

ARRL Business of the Future (March 2019 QST) - RF CafeYou've probably heard the old saying regarding "getting it into gear," when attempting to motivate a company, person, or group of people who are stuck in an intractable rut to start moving in a new direction. A couple years ago I ran across a drawing similar to the one shown here. It was on a technical venue where whoever used it should have recognized that as shown, the meshed gears would never move due to a rotation direction conflict (see my arrows). I posted a screen shot of it here on RF Cafe. The scheme as depicted is antithetical to the concept of motion. In fact, it is the very epitome of being locked in place with no hope of moving (other than slop between the cogs). Sadly - and I hate to even draw attention to it - the image shown appeared in the March 2019 issue of the ARRL's QST magazine. I know for a fact those guys are way, way smarter than I am, so how it slipped past the editors is a mystery. BTW, the other entity eventually corrected its mistake by "unmeshing" the three gears. ...

San Francisco Circuits Updates Turnkey PCB Assembly Capabilities

San Francisco Circuits Updates Turnkey PCB Assembly Capabilities - RF CafeSan Francisco Components (SFC) has updated its printed circuit board (PCB) turnkey assembly capabilities. Full turnkey PCB assembly through SFC reduces the customer's responsibility to source components (and the surrounding issues), manage the bill of materials (BOM), inventory, and logistics associated that can be encountered when working with a PCB assembly partner. SFC's turnkey and partial turnkey or consigned assembly options are designed to meet the individual needs of their customers, depending on how much of the assembly process they want to manage versus outsource. SFC's turnkey PCB specialists can help guide customers through the benefits of each approach and ultimately deliver the optimal product and service ...

Ultra-Low-Cost Flexible RFID ICS for Smart Packaging

Ultra-Low-Cost Flexible RFID ICS for Smart Packaging - RF Cafe"Designed for use in closed HF RFID systems, PragmatIC's PR1101 and PR1102 flexible integrated circuits (FlexICs) are the first products in the company’s ConnectIC family. Developed using PragmatIC's unique platform of patented technologies, ConnectICs deliver connectivity solutions at the lowest cost point in the market, claims the manufacturer, delivering an ultra-thin and flexible solution that can be embedded into a wide range of substrates, including paper and plastic. The devices reduce the complexity of inlays by using single layer antennas, delivering a further step down in cost to brand owners and retailers. These ConnectICs are extremely attractive ..."

KR Electronics: RF & Microwave Filters

KR ElectronicsKR Electronics designs and manufactures high quality filters for both the commercial and military markets. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop and individually synthesized filters for special applications - both commercial and military. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Please visit their website today to see how they might be of assistance ...

Monday 18

Little Known Facts About Dr. Robert M. Page

Little Known Facts About Dr. Robert M. Page - RF CafeJust about everyone who has worked in the radar field for a long time is familiar with the name of Dr. Robert M. Page. He was the first to come up with the concept of monopulse radar, and he invented the familiar Plan Position Indicator (PPI) radar display and the RF duplexer which allows one antenna to be connected to both the transmitter and the receiver. Amazingly, I recently received an e-mail from Dr. Page's son, John Page. An interest in his father's career combined with insight that only growing up under the loving care of Dr. Page can provide has afforded him some unique tidbits of information that many (most, per John) historical accountings omit. Rather than me summarizing his letter, you will want to read it yourself as presented below. World War II aficionados will particularly appreciate the information. John pays homage to his father's co-workers ...

VidaRF Intros Broadband Directional Couplers for 0.5-18 GHz

VidaRF Intros Broadband Directional Coupler for 0.5-18 GHz - RF CafeVidaRF, a manufacturer of high performance RF and microwave high performance isolators, circulators, power dividers, couplers, and other passive components, is proud to introduce the VDC-05180-XX line of Directional Couplers with SMA connector, operating from 0.5 to 18 GHz. It is available with coupling value of 10 dB, 20 dB and 30 dB and can handle up to 50 watts of RF power. VidaRF's product line includes drop-in, coaxial, and waveguide configurations for many items. Custom designs available ...

Electronics-Themed Comics, 1950s Radio & TV News

Electronics-Themed Comics, May 1952 and May 1956 Radio & Television News - RF CafeI don't know about the rest of the country, but this Monday morning in Erie, Pennsylvania, is cold and snowy. That means people going to work had to shovel their driveways, maybe brush snow and ice off their windows, and brave hazardous conditions on the streets on the way to the office. Moods are understandably less than jovial and nerves might be shot. For those of you who identify with this scenario, these electronics-themed comics from a couple vintage Radio & Television News magazines might help assuage your anxieties. The same goes for those who are in Southern California and managed to arrive safely from a commute on the notoriously unfriendly highways there. As with many of these old comics, you have to be privy to the mindset of the day to fully appreciate the topic. TV repair was big business and people were fascinated with the boob tube innovation rapidly consuming the attention of domestic dwellers ...

Circuit Platform Made of Strongly Interacting Microwave Photons

Circuit Platform Made of Strongly Interacting Microwave Photons - RF Cafe"A team of researchers at the University of Chicago has developed a circuit platform for the exploration of quantum matter made of strongly interacting microwave photons. In their paper published in the journal Nature, the group outlines their platform and how it might be used. As part of the effort to create a useful quantum computer, scientists have been investigating superconducting circuits, which are controllable, have long coherence times and have strong interactions - characteristics required when studying quantum materials with microwave photons. The researchers note also that photon losses in such circuits ..."

Innovative Power Products: RF & Microwave Passive Components

Innovative Power ProductsInnovative Power Products (IPP) has over 30 years of experience designing & manufacturing RF & microwave passive components. Their high power, broadband couplers, combiners, resistors, baluns, terminations and attenuators are fabricated using the latest materials and design tools available, resulting in unrivaled product performance. Applications in military, medical, industrial and commercial markets. Take a couple minutes to visit their website and see how IPP can help you today ...

Sunday 17

Engineering & Science Crossword Puzzle for February 17

RF Cafe Engineering & Science Crossword Puzzle February 17, 2019Beginning in 2000, I have created hundreds of 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 start 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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Webmaster:
    Kirt Blattenberger,
    BSEE - KB3UON

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 Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

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