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Homepage Archive - April 2019 (page 2)

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 | 5 of the April 2019 homepage archives.
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Friday 12

Electronics Inventors Quiz

Electronics Inventors Quiz, November 1963 Popular Electronics - RF CafeMost of these matches of the devices and its inventor are pretty easy for people who have been around electronics for any length of time (well, not if the length of time is a day or two), but a couple just might stump you. This Electronics Inventors Quiz appeared in a 1963 edition of Popular Electronics, so you won't be challenged with knowing the inventors of the LCD or MEMS devices, but neither will you have to know who came up with the abacus or the Archimedes screw :-) ...

Microsatellites Cluster for HawkEye 360's Commercial RF Geolocation Project

Microsatellites Cluster for HawkEye 360's Commercial RF Geolocation Project - RF Cafe"Small-Sat technology leader, Space Flight Laboratory (SFL), has received the prime contract to develop the next generation cluster of formation-flying microsatellites for HawkEye 360. The HawkEye Constellation, consists of multiple clusters of three satellites each. It is the first system of its kind to detect and geo-locate RF signals for maritime, emergency response, and spectrum analysis applications directly from space. SFL built the platforms and integrated the HawkEye 360 Pathfinder cluster which was launched into a low-Earth orbit in December 2018 and commissioned early this year. The three formation-flying Pathfinder microsatellites have successfully demonstrated geolocation of VHF ..."

All About Reed Relays

Reed Relays, April 1967 Electronics World - RF CafeThis April 1967 edition of Electronics World featured a handful of articles covering different types of relays and circuits for controlling them: reed relays, time-delay relays, stepping relays, mercury-wetted relays, resonant reed relays, operate and release times, relay coil considerations, and more. Even with the advent of transistor switching, there are still many uses in modern circuits for electromechanical relays, so this material should prove useful. Links are provided to the other relay articles ...

Custom MMIC Recognized as BAE Systems 2018 "Partner 2 Win" Gold Supplier

BAE Systems Recognizes Custom MMIC as a 2018 "Partner 2 Win" Gold Supplier - RF CafeWe're honored to be the only semiconductor supplier to receive BAE Systems' distinguished GOLD Supplier award for 2018. As part of their "Partner 2 Win" Supplier Program BAE Systems conducts a comprehensive annual review of all their key suppliers and brings the top performing suppliers together for an evening of appreciation and to acknowledge their outstanding support over the previous year. Dave Folding, VP of Operations, and Erik Sauve, Director of Quality, attended the Partner 2 Win Supplier Symposium ceremony held on April 2, 2019 and accepted the award on behalf of the Custom MMIC team. "We are both honored and proud to have been selected to receive this prestigious award from BAE Systems. This customer acknowledgement reaffirms Custom MMICs commitment to providing ...

Phased-Array Ka-Band Antenna Demos 2-Way Wideband Data Links

Phased-Array Ka-Band Antenna Successfully Demonstrates Two-Way Wideband Data Links - RF Cafe"ThinKom Solutions, Inc., has announced the successful completion of in-flight connectivity trials of its ThinAir Ka2517 phased-array antenna mounted on the Proteus high-altitude long-endurance aircraft. The Proteus satellite data communication package was developed as a joint effort involving ThinKom, Inmarsat Government and Scaled Composites. The trials included initial tests in Chantilly, Virginia and the Mojave Air and Space Port, California, culminating in a series of demo flights at White Sands Missile Range, New Mexico. The ThinAir antenna delivered a 25 Mbps return link and a 5 Mbps forward link operating at over 50,000 feet altitude through an Inmarsat Global Xpress Ka-band satellite in geostationary orbit ..."

Rohde & Schwarz USA: RF & Microwave, Analog, Digital, & Optical Test Equipment

Rohde & Schwarz USA Pocket Guides - RF CafeRohde & Schwarz develops, produces and markets test & measurement, information and communications technology. Focus is on test and measurement, broadcast and media, cybersecurity, secure communications, monitoring and network testing. Markets serviced are wireless, the automotive industry, aerospace and defense, industrial electronics, research and education, broadcast and media network operations, consumer electronics, cybersecurity for business and governments, communications and security solutions for critical infrastructures and the armed forces, reconnaissance equipment for homeland and external security, and much more ...

Thursday 11

Are You Ready for CONELRAD?

Are You Ready for CONELRAD?, April 1955 Radio & Television News - RF CafeBefore the Emergency Alert System (EAS) was activated on January 1, 1997, which followed the August 5, 1963 activation of the Emergency Broadcast System (EBS), there was the 1951 implementation of the CONtrol of ELectromagnetic RADiation (CONELRAD). Born out of the Cold War era, CONELRAD was devised in order to not just provide timely forewarning of enemy nuclear and/or bomber and/or submarine-based attacks, but also to silence all commercial broadcasters whose transmitting installation could potentially be exploited as homing signals for the aforementioned bad guys. The Germans had used just such a scheme during the recently concluded World War II to knock out Allied radio stations. CONELRAD used designated "clear channel" installations (no, not the moniker appropriated by iHeartMedia) whose super high power outputs would reach across the land to give warning to even remote areas ...

Direct Antenna Modulation to Improve Signal Quality

Direct Antenna Modulation to Improve Signal Quality - RF Cafe"Engineering researchers have demonstrated that a longstanding theoretical method called Direct Antenna Modulation (DAM) has real-world utility for boosting the quality of radio signals when transmitting at high data rates. The finding has applications in fields such as military communications. Signal quality can always be improved by using a larger antenna, but that's simply not practical for many wavelengths. For example, antennas operating in the high frequency range i.e from 3 to 30 MHz - would be 5 meters long or longer. DAM (Direct Antenna Modulation) can improve signal quality dramatically when using much smaller antennas. The researchers have demonstrated the concept using antennas one-third the size ..."

RF Stencils for Visio v3.1 Available!

RF Microwave Wireless Analog Block Diagrams Stencils Shapes for Visio - v3 - RF CafeWith more than 780 custom-built symbols, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every object has been built from scratch to fit proportionally on the provided A- and B-size drawing page templates (you can use your own page if preferred). Components are provided for equipment racks (EIA and ETSI) and test equipment, system block diagrams and conceptual drawings, and for schematics ...

The Propagation of Short Waves

The Propagation of Short Waves, December 1931/January 1932 Short Wave Craft - RF Cafe"Short waves," with their ability to support long distance communications under certain conditions, became a phenomenon in the late 1920s, and a market developed for converting commercial broadcast receivers to short wave receivers. Magazines at the time were full of advertisements for the devices. The particulars of short waves and the way they propagated in the upper atmosphere were not yet well understood early on. In fact, the government considered transmission frequencies above 1.5 MHz (≤200 meters) so useless that they assigned those bands to amateur radio operators. The presence of an electrically conductive layer, known as the ionosphere, was not verified until 1927 by Edward Appleton ...

Algorithms to Antenna: Where Should I Locate My Radar?

Algorithms to Antenna: Where Should I Locate My Radar? - RF CafeDid you know that planning is in the works to install a massive collection of radar surveillance cells across the country to monitor the airspace for aircraft - manned and unmanned - that have a low probability of detection by existing radars? Per this article by Rick Gentile, Jacob Halbrooks, and Honglei Chen, "In a previous blog, we wrote about ways to visualize antenna patterns on a map. We want to revisit this topic by sharing another example related to planning a small network of radar systems. First, a bit of background. The Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) at the University of Massachusetts Amherst has described a concept in which new gap-filling radars could be used to augment existing radar networks ..."

U.S. Army Using an Inflatable Satellite Antennas

U.S. Army Using an Inflatable Satellite Antennas - RF Cafe"The U.S. Army's 8th Army Unit soldiers, positioned in South Korea, have now been granted access to an inflatable satellite antenna. The soldiers are training on how to set up and use the Combat Service Support Very Small Aperture Terminal (CSS VSAT) Inflatable Satellite Antenna (ISA). For Army logisticians who sustain their units with critical supplies, repair resources and parts, one of their most important tools is the Combat Service Support Very Small Aperture Terminal (CSS VSAT), a mobile satellite terminal found everywhere they operate. Originally fielded in 2004, this workhorse was game changing for logisticians, allowing them to complete supply transactions and receive real-time status updates ..."

Thanks Once Again to everythingRF for Long-Time Support!

everything RF Searchable Database - RF CafePlease take a few moments to visit the everythingRF website to see how they can assist you with your project. everythingRF is a product discovery platform for RF and microwave products and services. They currently have 227,460 products from more than 1210 companies across 285 categories in their database and enable engineers to search for them using their customized parametric search tool. Amplifiers, test equipment, power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything else. Please visit everythingRF today to see how they can help you ...

Wednesday 10

All About Ovonics

All About Ovonics, May 1969 Radio-Electronics - RF CafeStanford R. Ovshinsky is a name with which most people are probably not familiar, even though some of his 400+ patented inventions can be found in many products. The most notable is the nickel-metal hydride (NiMH) battery. He also delved deep into phase change memory and amorphous semiconductors. What caught my attention in this 1969 Radio-Electronics magazine article was the claim that use of an ovonic switch matrix in conjunction with red, green and blue (RGB) phosphor light sources could produce the world's first large screen, flat panel video display that would not require scanning electron beams or rear projection. History shows that the idea never came to market, probably due to a combination of technical, financial, and manufacturability issues. Ovonics (a portmanteau of "Ovshinsky" and "electronics") is still used in aspects of the alternative energy industry ...

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

Engineering Job Board - R 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 ...

Design PCBs for EMI, Part 2: Basic Stack-Up

Design PCBs for EMI, Part 2: Basic Stack-Up - RF CafePart 2 of Kenneth Wyatt's "Design PCBs for EMI" series focuses on Basic Stack-Up strategy. "Part 1 of this series described how digital signals propagate through PC boards. In part 2, we look at specific board designs to achieve low EMI. The biggest issue I see in my clients' board designs is poor layer stack-up. Reiterating the two fundamental rules from part 1 and realizing digital signals and power (transients) are electromagnetic waves moving in the dielectric layer, we see there are two very important principles when it comes to PC board design: Every signal and power trace (or plane) on a PC board should be considered a transmission line. Digital signal propagation in transmission lines is really the movement of electromagnetic fields ..."

Transistor that Functions Perfectly at All Current Ranges

Transistor that Functions Perfectly at All Current Ranges - RF Cafe"Transistors, currently are used almost everywhere, ranging from mobiles and home appliances to aircrafts. But they often operate only within a restricted current range. Working towards solving this problem, physicists at LMU (Ludwig-Maximilians University) have now developed an organic transistor that functions perfectly under both low and high currents. Transistors are semiconductor devices that control voltage and currents in electrical circuits. To reduce economic and environmental costs, electronic devices must become smaller and more effective. This applies above all to transistors. In the field of inorganic semiconductors, dimensions below 100 nanometers are already standard ..."

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 ...

Tuesday 9

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 ... 

Thanks to TotalTemp Technologies for Continued Support!

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 ...

Carl & Jerry: Electrical Shock

Carl & Jerry: Electrical Shock, September 1955 Popular Electronics - RF CafeIn his usual manner, John T. Frye uses tech-savvy teenage experimenters Carl Anderson and Jerry Bishop to teach a lesson while writing a compelling saga. In this case Jerry gets "bitten" by house current while fiddling with a receiver chassis. Before certain safety measures were required by law, many electrical devices - radios, televisions, vacuum cleaners, shop tools, kitchen appliances, etc. - were sold with with either existing shock hazards or the potential for (no pun intended) a shock hazard in certain usage or failure modes. Before the advent of polarized two-pronged plugs and grounded 3-prong plugs, some devices presented hazardous voltage levels to the user by virtue of a direct connection to exposed conductive (metal) surfaces. In this instance, under normal operational conditions with the chassis installed in its wooden case and plastic or phenolic control ...

ConductRF Low PIM RF Cables

ConductRF Low PIM RF Cables - RF CafeConductRF offers a diverse range of solutions for common applications including Low PIM cables. Flexible and hand-formable, corrugated, multiple connector and cable combinations. ConductRF has a wide range of "Performance" related solutions built and 100% tested up to 70 GHz at our own facility. If your solution requires Low Loss or VSWR or if you have ruggedization or waterproofing needs, we see this as a performance solution which requires our expertise to turn in to finished product solution for you. Built in the USA ...

C-Band Debate Poised to Pivot

C-Band Debate Poised to Pivot - RF Cafe"While the C-Band Alliance (CBA) proposal for the 3.7-4.2 GHz band remains in the lead, other proposals for this important midband spectrum could catch up, according to analysts at New Street Research. The 3.7-4.2 GHz band, also referred to as the C-band, is seen as one of the best chances for the U.S.terrestrial wireless industry to get midband spectrum for 5G. However, while the wireless industry deems 100 MHz per carrier as the ideal for 5G, the current satellite companies occupying the C-band say they realistically are only able to relinquish 200 MHz out of the total 500 MHz for the sake of 5G. In a note to investors ..."

Monday 8

A New Approach to Long-Distance Transmission

A New Approach to Long-Distance Transmission, April 1955 Radio & Television News - RF Cafe This story in the April 1955 issue of Radio & Television News might be the first public disclosure of Bell Telephone Laboratories' flexible waveguide design. Operating at 50 GHz, the new waveguide will replace hundreds of existing coaxial cables that can each carry only 600 telephone channels and two television channels. It can also increase the distance between amplifiers from 12 miles to 50 miles. Construction consists of a hollow flexible tube lined with a spiral winding of copper wire. Incidentally, the lower cutoff frequency for circular waveguide with a 2-inch diameter, as reported here, works out to around 1.8 GHz. I was skeptical about the claim of operation at 50 GHz since that kind of spectrum was the domain of laboratories back in the day, not commercially deployed systems. 2 GHz was doable, so the new waveguide accommodated ...

The Parametric Measurement Handbook by Keysight

The Parametric Measurement Handbook, Keysight - RF CafeKeysight (formerly Agilent, formerly HP) has just published the 4th Edition of their very popular "The Parametric Measurement Handbook." It is 277 pages chock full of information of terminology and definitions, source / monitor unit (SMU) fundamentals, on-wafer measurements, time-dependent and high-speed measurements, making accurate resistance & capacitance measurements, and power device characterization. Hundreds of drawings and photographs help illustrate concepts. The price is right: Free for downloading!

Many Thanks to MECA Electronics for Their Long-Time Support!

MECA Electronics

Since 1961, MECA Electronics has designed and manufactured an extensive line of RF & microwave components for in-building, satellite, radar, radio, telemetry, mobile radio, aviation & ATC. Attenuators, directional & hybrid couplers, isolators & circulators, power dividers & combiners, loads, DC blocks, bias-Ts and adapters & cables. MECA has long been the 'backbone' of high performance wired and air-interfaced networks such as in-building applications, satellite communications, radar, radio communications, telemetry applications, mobile radio, aviation & air traffic communications ...

COTS Electronics Replace Legacy Systems

COTS Electronics Replace Legacy Systems - RF CafeMilitary & Aerospace Electronics is offering a free webcast titled, "COTS Electronics Replace Legacy Systems That Are No Longer Maintainable," which originally aired on January 29, 2019. Description: "The life cycle of many electronics systems is a long one often spanning decades and even generations. The F-16 is 42 years old and the B-52 is old enough to collect social security. However, both systems are still active and still need to be maintained even though they may be on third or fourth generation electronics. Industry is full of electronic systems that were developed over twenty years ago. Many of these are based on technologies, or at least products that can no longer be replaced or repaired. As firms and particularly the military try to keep their systems operational ..."

Liquid-Crystal Metasurfaces Enhances Lidar

Liquid-Crystal Metasurfaces Enhances Lidar  - RF Cafe"The market for lidar sensors for use in autonomous vehicles is now hotly contested; almost every month a new supplier appears on the scene. The US startup Lumotive now wants to grab one of the top places - with an innovative technology and a financial injection from Bill Gates himself. Gleb Akselrod, CTO and co-founder of Lumotive, explains that the difference to available lidar sensors lies in their beam steering technology. The engineers from Seattle in the U.S. state of Washington use a Liquid Crystal Metasurface (LCM) to control the infrared laser. This means that the entire Lidar sensor requires no mechanically moving parts and thus has the prospect of significantly increased reliability and a longer service life compared to its competitors ..."

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 ...

Sunday 7

Engineering & Science Crossword Puzzle for April 7

RF Cafe Engineering & Science Crossword Puzzle April 7, 2019Since 2000, I have been creating custom engineering-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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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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