Homepage Archive for September 2019 (Page #2)

A Primer on Single Sideband, September 1974 Popular Electronics - RF Cafe

Single-sideband (SSB) modulation was a big deal when it was first introduced at a time when the radio spectrum was getting pretty crowded - particularly in the commercial broadcast bands. It allowed more channels / stations to be packed into available space, which was obviously a good thing, but the other main benefit of SSB is the transmission efficiency - especially when a suppressed carrier format is used. At really high powers, electronic component, antennas, cabling, and facilities are very expensive, so being able to broadcast a signal over a given distance at a lower power represents a cost savings. As the old saying goes, though, "there is no free lunch." Modulators in transmitters ...

Get a Charge Out of Device Capacitance-Voltage Testing - RF Cafe

Axiom Test Equipment has posted a new blog entry entitled, "Get a Charge Out of Device Capacitance-Voltage Testing." Read their latest blog to learn what to look for when selecting test equipment for semiconductor device capacitance-voltage (C-V) measurements and learn how C-V measurements can greatly assist the modeling and design of circuits with semiconductor devices. "Transistors and integrated circuits (ICs) make many of our modern electronic 'toys,' such as cellular telephones and computers, possible. But before it is possible to reliably design supporting circuits for new semiconductor devices, they must be accurately tested to better understand their electrical characteristics. Last month's blog looked at the ways in which current changed with changing voltage. As a follow-up, this blog will explore capacitance ...

A.C. Calculations for Parallel and Series-Parallel Circuits, June 1944 QST - RF Cafe

When you read a lot of tutorials about introductory electronics on the Internet, most are the same format where stoic, scholarly presentations of the facts are given. Those of you who don't have enough fingers and toes to count all of the college textbooks like that which you have read know of what I speak. When hobby articles are written in a similar fashion, it can quickly discourage the neophyte tinkerer or maybe even a future Bob Pease. The ARRL's QST magazine has printed a plethora of articles over the years that are more of a story than just a presentation of the facts. My guess is the reason is because often the authors are not university professors who have forgotten how to speak to beginners. This article on basic calculations for AC series and parallel circuits is a prime example ...

"Have you ever accidentally misplaced your phone on a wireless charger and consequently woken up with a phone that has an almost empty battery? ZENS, a wireless charging expert has solved this problem with the launch of ZENS Liberty - a wireless charger with 16 overlapping charging coils. The 16 coils will give complete freedom of placement, allowing you to place two devices anywhere on the charging pad. So far, existing wireless chargers only have a few charging coils and your device needs to be placed on a specific spot on the charging pad. ZENS will launch two variations of the 16-coil wireless charger ..."

Electro-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.

The Hi-Fi Power Rating Hassle, October 1972 Popular Electronics - RF Cafe

President Ronald Reagan once stated that the nine most terrifying words of the English language were, "I'm from the government and I'm here to help." I share the sentiment generally while acknowledging that there are some areas where government oversight and regulation is needed. Problems arise where the opinions and beliefs of a self-appointed group of "experts" are allowed to impose subjective standards toward the creation of objective standards. Such was the case in the 1970s when the FTC sought to publish a set of rules by which high fidelity (hi-fi) stereo equipment manufacturers must publish performance parameters. The EIA had their own ideas for how equipment specs should be reported. Popular Electronics magazine published hundreds of product reviews for receivers, recording and playback devices, power amplifiers, equalizers, speakers ...

Nikola Tesla - Master of Lightning - RF Cafe

I ran across this full-length video of the documentary titled, "Nikola Tesla - Master of Lightning," which was aired by PBS in 2000. It is the most extensive visual resource of information on Tesla that I have seen. Most people, if they have ever even heard of Nikola Tesla, associate him with gigantic high voltage generators making his hair stand on end, but his contributions to the world of electricity go far beyond that. Aside from the lightning machines, he also developed almost single-handedly the basic concept of alternating current (AC) power generation, distribution, and motors. The battle, both personally and corporately, with Thomas Edison and his proposed direct current (DC) system is epic and tragic. Documentaries like this one tend to flourish the tale a bit with exaggerations that build sympathy for the featured good guy du jour ...

Custom MMIC Intros Low Noise Amplifiers for 2-16 GHz - RF Cafe

Custom MMIC, a leading designer and manufacturer of high performance monolithic microwave integrated circuits (MMICs), is proud to introduce three new Low Noise Amplifier (LNA) MMICs to its industry leading portfolio of high-performance RF and Microwave MMIC products. These three new GaAs devices offer customers a broad frequency range that addresses many popular wireless applications in the Aerospace, Defense and Instrumentation markets. The CMD308P4 is a broadband MMIC low noise amplifier housed in a leadless 4x4 mm plastic surface mount QFN package. The device operates from 2 to 6 GHz and delivers 31 dB of gain with a corresponding output 1 dB compression point of +12 dBm and a noise figure of 1.6 dB. The CMD308P4 includes on chip blocking capacitors and is internally matched to 50 ohms which eliminates ...

RF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge (of course a gratuity will be graciously accepted). 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors ...

Electronics and IGY, March 1958 Popular Electronics - RF Cafe

"The International Geophysical Year (IGY) was an international scientific project that lasted from July 1, 1957, to December 31, 1958. It marked the end, after Joseph Stalin's death, of a long period during the Cold War when scientific interchange between East and West was seriously interrupted. As many as 67 countries participated among which were all major ones with the exception of mainland China. The IGY encompassed eleven Earth sciences: aurora and airglow, cosmic rays, geomagnetism, gravity, ionospheric physics, longitude and latitude determinations (precision mapping), meteorology, oceanography, seismology and solar activity. Both the U.S. and the Soviet Union (USSR) launched artificial satellites ...

Navy's New Radar For Nimitz Class Carriers and Amphibious Assault Ships - RF Cafe

"A new generation of advanced and highly capable modular radar systems is going to be deployed across the Navy's fleet in many configurations. A staple feature on Nimitz class supercarriers and America's 'Gator Navy' of amphibious assault ships may begin to disappear in the not so distant future and in its place will be a very different looking system. The AN/SPS-48 three-dimensional air-search radar has been fielded across the Navy for over five decades. Today, a modernized version - the AN/SPS-48G - of the big, square, billboard-like, spinning array can still be found on Nimitz class carriers, San Antonio class landing platform docks, and Wasp and America class amphibious assault ships. But that is slated to slowly change ..."

Withwave RF & Microwave Components - RF Cafe

Withwave manufactures an extensive line of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch, board edge, panel mount), calibration kits (SOLT), a fully automated 4-port vector network analyzer (VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures for calibration and multicoax cable assemblies. Frequency ranges from DC through 110 GHz. Please contact Withwave today to see how they can help your project succeed.

Bell Telephone New Diode Speeds Voices, August 1958 Popular Electronics - RF Cafe

The first time I saw a microwave diode in this type of ceramic package was in the detector stages of the S-band airport surveillance radar (ASR) and the X-band precision approach radar (PAR) that made up the AN/MPN-14 radar system I worked on in the U.S. Air Force back in the late 1970s / early 1980s. Both radars were primarily vacuum tube systems with a few upgrades to solid state components in areas where suitable substitutes for the original tubes were available. By the time this Bell Telephone Laboratories advertisement appeared in a 1958 issue of Popular Electronics magazine, no transistors had yet been invented for operation in the microwave realm, at least not other than the "laboratory curiosity" type. It had only been a decade since Drs. Brattain, Shockley, and Bardeen announced ...

In this September 2019 Rohde & Schwarz newsletter, we provide you the latest information in RF Measurements, Signal and Power Integrity. We've curated the most recent documents, videos and webinars to support you in your on going education. Included are Making Effective Use of Doherty Architecture, Measurement of the Phase Difference Between Several Signals, and our Mixer & Frequency Converter Fundamentals Seminar on October 16th. If you'd like to learn more, talk to your dedicated representative, get a product demo or quote, please click on the button below. We're here to support your projects and business needs.

If you or someone you know is just starting in the realm of radio and want a really nice pictorial presentation of the basics of radio wave propagation, then this one-page article from a 1935 edition of Short Wave Craft is just what you need. Phormula phobia (aka formula fobia) will not be an issue for anyone. The fundamentals have not changed in the intervening 85 years, and this same sort of analogy is still used in introductory physics classes today.

Electro-Photonics Intros 500 MHz-50 GHz RF & Microwave Filters - RF Cafe

Electro-Photonics LLC, a market leader in RF and Microwave components has released a new series of band pass filters featuring frequencies from 500 MHz – 50 GHz. Our new wide bandwidth filters future high stop band suppression and compact size. These RF/Microwave and mmWave filters can dissipate up to 20 W of continues wave power. Electro-Photonics, LLC, is a global supplier of high-frequency components and services. Our products include, SMT hybrid and directional couplers, high frequency test fixtures, evaluation test boards, and wire bondable passive components.

"A team of researchers from the Institute of Science and Technology Austria demonstrated a quantum radar that relies on using entangled photons and operates at such low power levels that it can hide behind background noise, making it useful for biomedical and security applications. One of the advantages of the quantum revolution is the ability to sense the world in a new way. The general idea is to use the special properties of quantum mechanics to make measurements or produce images that are otherwise impossible. Much of this work is done with photons. But as far as the electromagnetic spectrum is concerned, the quantum revolution has been a little one-sided. Almost all the advances in quantum computing, cryptography, teleportation ..."

TotalTemp 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. Please contact TotalTemp Technologies today to learn how they can help your project.

Islamic terrorist attack on UAL Flight 93, September 11, 2001 - RF Cafe

Islamic terrorist attack on the Pentagon, September 11, 2001 - RF Cafe

Islamic terrorist attack on the twin towers, September 11, 2001 - RF Cafe

Incredibly, 18 years has passed since the extremist Islamic attack on American soil on the morning of September 11, 2001. Nearly 3,000 citizens died that day. World leaders have embarked on a path of colonizing our homelands with groups of people that are known to harbor sympathies for the terrorists. They dwell among us now and mean to do us harm when opportunity presents itself - which it has on numerous occasions in the past many years. Never forget the people who died in the burning towers, the Pentagon, and the airplanes, and those left behind to grieve and get on with life. Never forget the police and military members who fought - and some died - to keep us safe and free. Never forget the rotten politicians who imperil our existence with their selfish agendas.

The Electron Microscope, May 1955 Popular Electronics - RF Cafe

This article published in a 1955 issue of Popular Electronics magazine is a really good primer on the history and working principles of the electron microscope. It also explains why such a device is needed; i.e., why an optical microscope cannot do the job when really high levels of magnification are required. As object dimensions are spaced at distances near to or less than the optical wavelength being observed, it becomes impossible to resolve into separate features. Accordingly, when observing at the upper end of the visible light spectrum at around 400 nm, under ideal conditions you would not be able to clearly discern two feature less than about 800 nm apart. Current (2019) CMOS gate thicknesses run about 5 μm, so visible light cannot be used to image those structures. Another resolution limiting factor is aperture size, which, depending on the wavelength causes diffraction patterns of two objects to overlap ...

A few decades ago I might have begun this sentence with, "Most of us know about 'The War of the Currents' that pitted Tesla's AC power distribution scheme against Edison's DC scheme." However, I'm not so sure the epic techno-battle has ever been heard of by those among us who entered the electrical / electronics world within that timespan - that is unless he or she is a frequent visitor to RF Cafe, where I make a point of reminding devotees of the places from whence we came. Fortunately, some movie producers appreciate science history and share the desire to present it to their audiences. Some include a political agenda while others stick to the facts (with a little artistic license thrown in, including modifying the most commonly used title). "The Current War" movie is coming to theaters in October. Hopefully, we'll get just the facts.

Radio Astronomy, June 1954 Radio & Television News - RF Cafe

Super-low-noise-figure receivers are absolutely essential in radio astronomy work. The need has driven major advances in the state of the art of cryogenically cooled front ends with noise temperatures near absolute zero. Antenna technology has also benefitted from radio astronomy due to the need for precision steering and narrow beam widths. Phased arrays (aka interferometers) for interstellar targets requires that element spacing be large enough to require separate antennas as the elements, which creates a very large effective aperture, hence greater angular resolution. Networks located continents apart are synchronized with the use of atomic ...

Stacked 9- & 17-Element Yagi TV Antenna Project (Dave Jones, N1UAV), Kirt's Cogitations #314 - RF Cafe

Antenna builder extraordinaire Dave Jones (N1UAV) outdid himself by replacing his 9-element dual stacked Yagi antenna array with a 17-element version. He provides some written instructions and, most helpfully, a YouTube video showing how he did it. There is also a parts list that, where possible, has Lowe's item numbers for easy procurement. Dave originally sent me a note back in July about the stacked television antenna project he undertook after finding the "How to Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts" article from the November 1965 issue of Popular Electronics magazine here on RF Cafe. He lives in an area prone to multipath effects when receiving signals from a rather distant television station, so he decided to muster his considerable antenna building skills to see whether a stacked array would work for him ...

Metal Corrosion Sensor Mounts on PCBs - RF Cafe

Designed to help prevent equipment failure, Mitsubishi Electric's metal corrosion sensor is small enough to mount on a PCB and detect the progressive metal corrosion caused by exposure to aggressive atmospheres, such as those containing sulphur compounds. Each sensor consists of a thin metal film with resistors. The progress of any corrosion can be gauged by measuring the increase in electrical resistance of the corrosion sensors, which can be adjusted by changing the composition and thickness of their metal content. The 1.6x0.8 mm device can be deployed as multiple sensors with different levels of corrosion resistance in order to detect various degrees of corrosion in stages, helping industrial OEMs to prevent ...

Custom 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.

Cleveland Institute of Electronics "Troubleshooters", January 1968 Popular Electronics - RF Cafe

The Cleveland Institute was one of many electronics training organizations that exploited the rapidly growing electronics service industry in the last century. Although this particular two-page spread appeared in a 1968 issue of Popular Electronics magazine, the trend began back in the 1930s. Earlier electronics hobby and professional electronics publications like Short Wave Craft and Radio News were pitching the unlimited opportunities for anyone with the smarts and motivation for technical subjects as employees and/or owning a business. Even in the days when there were user-serviceable parts (primarily vacuum tubes and fuses) inside many electronic products, few people were willing to risk causing harm to themselves or their hard-earned radio and television sets. Even by 1968 when most of the electronics industry had shifted to solid state circuitry, the vast majority of existing equipment still had tubes in them. The television set my parents owned ...

Anatech Electronics Product Update September 4, 2019 - RF Cafe

Anatech Electronics, Inc. offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Anatech has introduced three new filter designs for the 5G NR (New Radio) bands: an n257 Band / 26.1 GHz cavity bandpass filter with N-type connectors, an n258 Band / 28 GHz cavity bandpass filter with 2.92 mm (SMA) connectors, and an n260 Band / 39 GHz cavity bandpass filter with 2.92 mm (SMA) connectors. Custom RF filters designs are used when a standard cannot be found, or the requirements are such that a custom approach is necessary.

"All-American" TV Technicians Win General Electric Awards for Public Service, February 1958 Radio-Electronics - RF Cafe

In the middle of the last century, television technicians were considered nearly as god-like as doctors, especially those who made house calls to cure an ailing entity - be it a TV with its vertical synch circuit running amok or a child running a fever. OK, I exaggerate a bit, but General Electric mounted a media campaign to build a favorable image of TV repairmen in the public eye. People from every walk of life and of every type employment (ok, maybe not mafia hit men and politicians), gave of their free time to help community efforts in charitable ways without any expectation of returned favors (which is why I included politicians along with mafia hit men). This 2-page advertisement which appeared in a 1958 edition of Radio-Electronics depicted TV technicians who were bestowed the "All American Award" for public service ...

World's Most Powerful RF Emulator National Wireless Research Asset - RF Cafe

The Colosseum - a massive RF channel emulator used to run DARPA's Spectrum Collaboration Challenge - transitions to National Science Foundation's PAWR Program after October finale. Over the past three years, DARPA's Spectrum Collaboration Challenge (SC2) has relied on a custom-built virtual testbed called the Colosseum to host thousands of competitive matches and scrimmages, which will include the final match to determine the winner of the $2M grand prize. Supporting SC2's mission to reimagine new spectrum access strategies in which radio networks autonomously collaborate to determine how the RF spectrum should be used moment-to-moment required the development of a research environment capable of emulating communication signals at real-world scope and scale. Working with engineers ...

Transient Specialists specializes in EMC test equipment rentals and carries a complete line of ESD guns, surge immunity test equipment, and EFT generators. Rentals available for military (Mil-Std 461), automotive (ISO 7637), and commercial (IEC 61000-4) EMC testing. Flexible terms, accredited calibrations and technical support on EMC testing equipment offered. Equipment consists of top EMC Test System manufacturers, including Teseq, Thermo Keytek, EM Test and EMC Partner. Contact Transient Specialists today for your ESD / EMC / RFI testing needs.

Engineering & Technical Headlines Crossword Puzzle September 8, 2019 - RF Cafe

This RF Cafe Engineering & Technical Headlines Crossword Puzzle contains at least 10 words from headlines posted on the homepage during the week of September 2 through September 6, 2019 (marked with an asterisk*). These custom-made engineering and science-themed crossword puzzles are done weekly for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. Every word and clue - without exception - in these RF Cafe puzzles has been personally entered into a very large database that encompasses engineering, science, physical, astronomy, mathematics, chemistry, etc. Let me know if you would like a custom crossword puzzle built for your company, school, club, etc. (no charge).

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.

2012: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 (no archives before 2012)