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Homepage Archive - February 2020 (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

2020:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
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
2014:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2012:  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13


See Page 1 | 2 | 3 | 4 | of the February 2020 homepage archives.
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Friday 21

Milestone in Space Communication

Milestone in Space Communication, February 1973 Popular Electronics - RF CafeIn 1971 the International Telecommunications Union (ITU), convened a meeting dubbed the World Administrative Radio Conference for Space Telecommunications (WARC-ST). The ITU was a specialized agency of the United Nations for telecommunications, with a membership of 140 nations. Satellite communications was barely a decade old, but already the need for international agreements on spectrum usage had become very apparent. Prior to the 1971 meeting, there was the 1963 Extraordinary Administrative Radio Conference held in Geneva, Switzerland. Amateur radio had its presence in the game acknowledged with further allocations for its members' OSCAR birds; six had been flown already. As of this writing there are about 20 OSCAR satellites still in operation. Amateur satellites take many forms these days, including the newest trend in CubeSat platforms with a well-defined set of specifications on dimensions and mass per cube. Launches are provided on a space available basis at a substantially discounted cost...

Copper Mountain Technologies Partners with Purdue University

Copper Mountain Technologies Becomes Corporate Partner of Purdue University - RF CafeTo help grow the next generation of RF Engineers, Copper Mountain Technologies (CMT) has become a corporate partner with the Purdue University Electrical and Computer Engineering (ECE) Program in West Lafayette, Indiana. The mission of CMT is to extend the reach of engineers by providing vector network analyzers that are portable, accessible, and affordable. By partnering with Purdue, we hope to promote growth in the increasingly important field of RF engineering. Despite a recent rise in engineering students and degree options, there is a shortage of RF engineers. With the abundance of wireless and IoT devices being created around the world, the requirement for engineers researching, designing, and working with these devices has grown and the demand for these professionals is not being met. There is a wide range of job opportunities for RF engineers in industries...

Hams in Combat -One Life to Give

Hams in Combat - One Life to Give, July 1944 QST - RF CafeQST did a regular series of articles titled "Hams in Combat" during World War II. This story is unique in nature in that it tells of a newspaperman-turned-soldier who, in the story writer's mind, would have been the most suited for the job of author. It tells a far different story of the South Pacific than we were treated to in weekly episodes of McHale's Navy! "Had this story been written by the man who should have written it - Capt. William H. Graham, W9BNC - it would have been one of the greatest "Hams in Combat" yarns ever told in these pages. But Bill Graham never got around to writing his story. He was too intensely occupied with the living of it - too keenly aware of the new paragraph... Note the letter I received from Capt. Graham's great grandson.

Improving 5G Network Security

Improving 5G Network Security - RF Cafe"Emerging 5G mobile wireless networking technologies are slated to dramatically increase in both scale and speed, enabling much faster access to data collected from billions of connected devices. This supercharged information highway is envisioned to play an important role across several industries, ranging from medicine to manufacturing. Major advances in 5G, including new core network features will make it easier to customize the network at a wide variety of locations. This new flexibility offers many benefits, but at the same time introduces novel security challenges. Today's proprietary 5G technologies make it difficult to achieve the transparency necessary for security-related risk analysis and mitigation. This lack of security assurance makes it harder..."

How to Derive -40°F = -40°C

How to Derive -40°F = -40°C - RF Cafe UniversitySome of what you and I consider common knowledge is largely unrealized by most people. Call me a geek, but I take pleasure in pointing out to people that the Fahrenheit and Centigrade scales are equal at -40°, and I especially enjoy working out the simple proof for them. Most people appreciated the effort and are amazed, claiming to have never seen that before. When I read the following in Smithsonian magazine, "Winter temperatures here, some 250 miles northeast of St. Petersburg, sometimes plunge to minus 40 degrees Fahrenheit," I wondered whether the author knew that -40°F = -40°C. Maybe he just didn't want to confuse his readers by omitting the redundant superfluous 'F' or 'C,' and it couldn't be 'K' because there are no negative Kelvin degrees. It could also be that he knew but figured most people do not...

Custom MMIC: Off-the-Shelf and Custom MMICs

Custom MMIC- RF CafeCustom MMIC is a fabless RF and microwave MMIC designer entrusted by government and defense industry OEMs. Custom and off-the-shelf products include switches, phase shifters, attenuators, mixers and multipliers, and low noise, low phase noise, and distributed amplifiers. From next-generation long range military radar systems, to advanced aerospace and space-qualified satellite communications, microwave signal chains are being pushed to new limits - and no one understands this more than Custom MMIC. Please contact Custom MMIC today to see how they use their modern engineering, testing and packaging facility to help your project. 

Thursday 20

A New Approach to Beam Antennas

A New Approach to Beam Antennas, February 1950 Radio & Television News - RF CafeThis article describes a method for tuning beam antennas from the ground rather than needing to experiment with matching capacitors and/or inductors at the antenna end of the transmission line. The scheme uses a separate length of transmission line attached to the reflector element at a length an integer number of half-wavelengths as required to reach the ground. That way, tuning elements can be installed and adjusted for one or more bands without needing to climb up to the antenna. The method can be used for any number of elements, but of course it could get a bit messy with more than a couple. The author, Major Charles E. Spitz (W7JHS), describes using a field strength meter to verify tuning correctness. Having read many QST magazine articles on antennas over the past decade or so...

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 (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...

Atoms Can Receive Common Communications Signals

Atoms Can Receive Common Communications Signals - RF Cafe"Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a new type of sensor that uses atoms to receive commonly used communications signals. This atom-based receiver has the potential to be smaller and work better in noisy environments than conventional radio receivers, among other possible advantages. The NIST team used cesium atoms to receive digital bits (1s and 0s) in the most common communications format, which is used in cell phones, Wi-Fi and satellite TV, for example. In this format, called phase shifting or phase modulation, radio signals or other electromagnetic waves are shifted relative to one another over time. The information (or data) is encoded in this modulation..."

90° Hybrid Coupled Power Amplifier Pros and Cons

90° Hybrid Coupled Power Amplifier Pros and Cons - RF CafeAn app note entitled "90° Hybrid Coupled Power Amplifier Pros and Cons," by NuWaves Engineering's Justin Wells, appeared in the latest edition of Aerospace & Defense Technology magazine. Mr. Wells has authored other app notes that, like this one, does a good job of distilling complex topics into articles understandable by newcomers to the RF trade. It begins, "Power Amplifiers (PAs) are commonplace in radio frequency (RF) systems extensively used in applications consisting of over-the-air wireless communications. Wireless communications is a broad market and PAs fill a wide array of those applications. Due to the broad range of applications, PA design techniques must be chosen carefully for each application-specific scenario. Single-ended PAs have limitations that restrict their practicality in many applications, especially where higher output power..."

Teledyne 2 in 1 Dual L/S-Band SSPA for Satcom C&C

Teledyne Paradise Datacom 2 in 1 Dual L/S-Band SSPA for Satcom Command & Control - RF CafeTeledyne Paradise Datacom, part of the Teledyne Defense Electronics Group, today announced the wide availability of a new, leading edge L- and S-Dual Band solid state power amplifier (SSPA) for today's evolving satellite command systems. Both S- and L-band frequencies have been the industry's bands of choice for positioning and tracking applications like global positioning systems (GPS) and Tracking, Telemetry, and Control (TTC) ground stations. This new dual band product offers customers a virtual "two for the price of one" SSPA solution that dramatically lowers the costs of command and control, leaves a much smaller footprint, but also delivers higher reliability compared to traditional klystron power amplifiers...

Nova Microwave: RF & Microwave Circulators & Isolators

Nova Microwave Circulators & Isolators - RF CafeNova Microwave is a leader in technically differentiated electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control critical commercial and military wireless telecommunications systems. Our staff is dedicated to research and development of standard and custom design quality Ferrite Circulators and Isolators from 380 MHz to 26.5 GHz. Available in single or multi-junction topographies, the Nova Microwave product line of is specifically designed for use in varied environmental and temperature extremes. 

Wednesday 19

Jury Told of Fraud in Radio Telephone (1917 NYT)

Jury Told of Fraud in Radio Telephone (New York Times - Thursday, November 27, 1913) - RF CafeMotivated by the series of articles about Lee de Forest in the January 1947 issue of Radio-Craft magazine, I did a search of U.S. newspapers from 1905 through 1947 looking for news items on him. In particular, I was hoping to find something about the lawsuit levied by the Marconi Company against Lee de Forest wherein the judge was reported to have told him, "...to forever desist from the manufacture, sale or operation of any system of wireless telegraph." Alas no such information was discovered, but the search will continue. I did find this piece and many other interesting items that will be posted as time permits. Here, Mr. de Forest sued, with the assistance of the U.S. Government, an investment company for defrauding investors in regard to company stock sales, using a charge of mail fraud to assist in prosecution. Mail fraud, tax evasion, interstate commerce and other such non-state related charges were (and still are) routinely used by the Feds...

Electronic Wrist-Watches

Electronic Wrist-Watches, February 1973 Popular Electronics - RF CafeTry as I did, I could not find any instance of the Ness Clocks all-digital liquid crystal display (LCD) desktop clock which appeared in this 1973 Popular Electronics article. There must not have been many produced. LCDs had only been commercially available for a year or so when this went on sale. Of the relatively few digital display clocks and watches available in the 1970s, the vast majority used light-emitting diodes (LEDs), and most sold for north of $100 (~$600 in today's money). Portable devices with digital displays really began to flourish with the advent of both CMOS circuitry and LCD displays; i.e., low current devices that extended battery life. Wrist watches, which could only accommodate very small batteries with limited energy storage capacity, were amongst the greatest beneficiary...

Transistors Both Process and Store Information

Transistors Both Process and Store Information - RF Cafe"A computer chip can process and store information using two different devices. If these devices could be combined into one or put next to each other, there would be more space on a chip, making it faster and more powerful. Engineers have developed a way that the millions of tiny switches used to process information (transistors) could also store that information as one device. The method accomplishes this by solving another problem: combining a transistor with higher-performing memory technology than is used in most computers, called ferroelectric RAM. Researchers have been trying for decades to integrate the two..."

VITA67.3 Nano Miniature RF Cables for VPX Systems

VITA67.3 Nano Miniature RF Cables for VPX Modular Systems - RF CafeConductRF's close partnership with TE in its development of its new Nano-miniature RF Solutions for VITA67.3 has put us in a great position to support your VPX RF cable assembly needs. Modular solution supports 8 to 18 positions, flexible 0.047" diameter cable, supports frequency up to 70 GHz, use with standard solutions (SMA, SMPM, etc.), 2x density of Vita67.1. ConductRF's PFT33 Series of Micro Flexible Cable Assemblies has been designed directly with TE Connectivity involvement and in partnership to maximize the capabilities of TE's new Vita67.3 NanoRF VPX modular connector system. ConductRF offers its soft FEP jacketed ø0.047" cable to facilitate maximum flexibility and provides solutions for jumper cables ...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF 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...

PCB Directory: Printed Circuit Board Fabrication & Assembly

PCB  Directory - RF CafePCB Directory is the largest directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet. We have listed the leading printed circuit board manufacturers around the world and made them searchable by their capabilities - Number of laminates used, Board thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing, fabrication, assembly, prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.

Tuesday 18

Lee de Forest - Father of Radio

Lee de Forest - Father of Radio, January 1947 Radio-Craft - RF CafeLee de Forest, upon whom was conferred the honorary title "Father of Radio" by Radio-Craft editor Hugo Gernsback (and others), exemplifies personal traits of most great inventors: high intelligence, stick-to-itiveness, courage, passion for his subject, determination, and a willingness to endure a lot of personal and financial abuse. The January 1947 issue of Radio-Craft magazine celebrated the 40-year anniversary of Mr. de Forest's invention of the Audion vacuum tube by including a large number of articles by various authors who knew him personally and attest to his greatness. I will be posting a few of those pieces, and you will probably be shocked at some of the shenanigans that went on by conniving people and naysayers who tried to deny de Forest due credit. For example, based on his work to make more sensitive receivers a judge in a lawsuit brought by Marconi strictly enjoined him "to forever desist from the manufacture, sale or operation of any system of wireless telegraph...

Rad-Hard Microelectronics for Space Applications

Rad-Hard Microelectronics for Space Applications - RF CafeThis article entitled "Rad-Hard Microelectronics for Space Applications," from the February issue of Aerospace & Defense Technology magazine, does a nice job of boiling down the most significant problems and solutions faced by engineers and scientists. Due to the high weight and volume required to sufficiently shield electronics from the effects of damaging space-borne particles and rays, methods have been devised to live with some of the damage while still being able to function - even if in a crippled mode. Redundancy is a big part of the strategy, as is actively monitoring and avoid ejecta from the sun, known debris from asteroids, comet tails, asteroids, and man-made space junk.

Carl and Jerry: Ham Radio

Carl and Jerry: Ham Radio, April 1955 Popular Electronics - RF CafeHere is another exciting episode of the sleuthing adventures starring Popular Electronics' tech savvy teenagers, Carl and Jerry. The Hardy Boys of electronics are the creation of author John T. Frye, who created short story adventures for many years - long enough to at one point require a major modification in the boys' appearances to reflect more modern attire and eyewear (Carl's "The Far Side"-style glasses had to go). This particular adventure begins with Carl considering whether his ham radio hobby is more useful from the standpoint of its technical aspects or of its social aspects.

U.S. Marines Sponsor Ham Radio Licensing Course

U.S. Marines Sponsor Ham Radio Licensing Course - RF Cafe"U.S. Marines with Information Group II Marine Expeditionary Force (II MIG) participated in an amateur radio general licensing course January 27 – 31 on base as part of the group’s High Frequency Auxiliary Initiative. Members of the Brightleaf Amateur Radio Club of Greenville, North Carolina, helped the Marines in the class learn the principles of HF radio operations as a contingency against a peer-to-peer adversary in real-world operations. During the course, Marines learned ham radio theory, band allocations, conventional and field-expedient antenna theory, and general ham radio operation and control. II MIG Commanding Officer Colonel Jordan Walzer created the High Frequency Auxiliary Initiative after recognizing the need for additional options in combat environments..."

Video: In-Circuit Antenna Verification

Copper Mountain Technologies Video: In-Circuit Antenna Verification - RF 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. In this video entitled, "In-Circuit Antenna Verification," CMT's Brian Walker, Senior RF Design Engineer, shows how there can be significant variation of performance of a PCB mounted antenna when it is close enough to other objects to disturb the near field response. It is best to measure the return loss of an embedded antenna in its final configuration and be prepared to add matching elements to improve radiation efficiency...

Empower RF Systems: RF & Microwave Power Amplifiers

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.

Monday 17

Choosing the Right Antenna

Choosing the Right Antenna, September 1958 Radio & TV News - RF CafeWhereas this "Choosing the Right Antenna" from a 1958 issue of Radio & TV News magazine article concerns television antennas, the information applies generally for any application. Folded dipoles, conicals, Yagis, log periodic, and other types were used by homeowners sometimes desperate to receive a good signal from a far away broadcast station or from a location buried in obstacles (terrain, buildings, water bodies, automobiles, towers, etc.) blocking and reflecting otherwise strong signals, thus causing fading and multipath degradation. You might think the advent of cable and satellite TV, along with Internet access, might have removed the need for rooftop type over-the-air antennas, but it is not so. There are still plenty of people located in rural areas that struggle to get a good signal, as evidenced by RF Cafe visitor Dave Jones, (N1UAV) stacked 9- & 17-element yagi TV antenna project...

Developing Nano Antennas for Data Transfer

Developing Nano Antennas for Data Transfer - RF Cafe"A team of physicists from the University of Würzburg is hard at work developing technology that could one day allow for the creation of nanoscale antennas with remarkable data transfer properties. Theoretically, these nanoscale-sized directional antennas would have the power to share data between different core processors at the speed of light. In a paper published in the journal Nature Communications, physicists explained how they were able to generate directed infrared light with the help of an antenna that is both electrically driven and made out of gold. But this was no typical antenna; known as a Yagi-Uda antenna after the researchers who invented it back in the 1920s, this device has a few special features that set it apart..."

Blind to Learn Radio with Braille Diagrams

Blind to Learn Radio with Braille Diagrams, February 1935 Short Wave Craft - RF CafeUnless you live with or interact regularly with someone who is blind, it is easy to forget the difficulty everyday life poses for him or her. I do not know any blind people. A lot of effort has been put forth to help facilitate those who are severely sight impaired or totally blind. Helen Keller is probably the most well-known blind person (she turned out to be an outspoken Socialist Party member - ugh), but I think of Ray Charles when the subject arises. Melanie and I visited the Florida School for the Deaf and Blind while in St. Augustine a few years ago, where we learned Mr. Charles was fortunate to have attended as a child. His rendition of "America the Beautiful" is by far my favorite. This article from a 1935 edition of Short-Wave Craft reports on efforts to make the electronics trade accessible to blind people via, in this case, pseudo-Braille versions of schematics. Although theoretical design and analysis activities were possible, the potentially lethal...

Custom Control Sensors List Added on Vendor Page

Custom Control Sensors - RF CafeSince the late 1950's, Custom Control Sensors (CCS) has been a leader in providing pressure, temperature and flow sensing products that include sensors and switches for the Aerospace, Defense, Industrial and Energy industries. Headquartered north of LA in Chatsworth, CA, CCS is a full service company offering complete build to specification design, research and development, 3−D modeling, prototyping, manufacturing, testing, quality control and aftersales support capabilities. CCS has pioneered many programs from the original NASA spacecraft to leading commercial aircraft, to USAF fighter jets and bombers, and International Space Station (ISS). Custom Control Sensors is now listed on RF Cafe's "Sensors" vendor page. Please visit them to see if they can help with your project needs.

NEW - RF & Electronics Symbols for Visio

RF Electronics Wireless Analog Block Diagrams Symbols Shapes for Visio - RF CafeWith more than 1000 custom-built symbols, this has got to be the most comprehensive set of Visio Symbols available for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or use your own). Symbols are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing. The file format is XML so everything plays nicely with Visio 2013 and later. ...

Anatech Electronics: Off-the-Shelf and Custom RF & Microwave Filters

Anatech Electronics logo - RF CafeAnatech 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. 

Sunday 16

Engineering & Science Crossword Puzzle February 16

Engineering & Science Crossword Puzzle February 16, 2020 - RF CafeHere is a science and engineering-themed crossword puzzle for your next long flight or boring meeting. This one for February 16, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. 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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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...

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