1996 - 2016
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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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.
Homepage Archive Pages
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Pasternack Ready-to-Use Semi-Rigid Test Probes for up to 6 GHz
Pasternack debuts a new line of semi-rigid test probes designed to assist in testing microwave circuits. By soldering the outer conductor to the signal ground and the exposed center conductor to the trace carrying the signal of interest, sampling measurements with these probes can be made without having to create a separate subassembly circuit board or add a connector to the circuit layout which can take up valuable real estate. Pasternack's new test probes are offered in 3 different diameters of semi-rigid ...
Webinar: Faster Analysis of Complex RF Signals (Using Power Sensors)
Defeating AdBlock Plus™
As someone who spends a lot of time surfing the Web in search of interesting electronics and technical news, I am painfully aware of the annoyances caused by intrusive, overwhelming advertisements. The most detestable are the full-screen ads that get in your face before ever seeing the webpage, and/or once on the page some cursed ad with video and audio plays automatically. It is no wonder that an exponentially increasing portion of Internet users are employing ad blocking software. If you are an advertiser paying for proprietary representation on a website, you are advised to determine whether your ads can be blocked. ...
MIT Researchers Turn Graphene Light On and Off
"A team of international researchers from the U.S. (MIT), Israel, Croatia, and Singapore, have discovered that under certain circumstances, a flow of electric current running through a sheet of graphene can exceed the speed of slowed-down light and produce a kind of optical 'boom': an intense, focused beam of light ..."
The Ham Who Was President
Since this is a presidential election year, I figured it would be a good time to post a tongue-in-cheek- story that appeared in the November 1952 issue of QST magazine about a fictional American president J. Willoughby Winkelspoof. The American Radio Relay League (ARRL) always has been and still is apolitical, so don't take seriously anything you read here. If you are an astute follower of politics, you might pick up on the nuances woven into the story, and might even marvel on how much the political landscape has changed in the half century since Pres. Winkelspoof graced the Oval Office ...
Peregrine Semiconductor Breaking High Frequency Barriers in RF SOI
Our UltraCMOS® high frequency portfolio debunks the industry's perceived boundaries of RF silicon-on-insulator (SOI) technology. It is our UltraCMOS technology platform that enables Peregrine to reach these high frequencies without compromising performance or reliability. At the International Microwave Symposium (IMS) 2016, we announced the addition of the UltraCMOS PE41901 image reject mixer into our growing portfolio ...
Keysight Intros SystemVue Phased Array Beamforming Kit
"The W1720 Phased Array Beamforming Kit provides system architects in 5G, Radar/EW, and Satellite communications with the essential tools to evaluate phased array and beamforming subsystems, including RF, Digital, and Hybrid beamforming architectures. Consider RF nonlinear & noise effects, Gain/Phase quantization, and Monte Carlo variations effects on total beam quality, sidelobe levels, and effective radiated power. Also supports dynamic system-level scenarios with algorithms for adaptive beamforming ..."
Comics in Electronics Magazines
Unashamedly I offer up these vintage yet timeless electronics-themed comics for your enjoyment. I freely admit to reaching for the comics page(s) of the newspaper to read the latest antics of Beetle Bailey, Dilbert, Hagar the Horrible, Peanuts, Blondie, and many others. As if that was not bad enough in some people's opinion, what would really keep me from getting invited to any more high class dinner parties if the word got out is the fact that I actually try to spot the 6 differences in Bob Weber, Jr.'s drawings ...
Graphene Can Have a Tunable, Stable Bandgap
"The knock against using graphene in digital electronics has been that it lacks an inherent band gap. However, over the years there have been a number of approaches that have been able to engineer a band gap into the material. One of the most promising methods has been nitrogen doping, which actually increases the material’s conductivity rather than reduces it. Now researchers ..."
Bluetooth 5 Bringing Double Range, Quadruple Speed
"Bluetooth 5 is set to make its formal debut June 16 at the Discover Blue media event in London, reported the Bluetooth Special Interest Group (SIG). The wireless standard is getting a major upgrade from Bluetooth 4.2. The newest version of Bluetooth will pack twice the speed, and four times the range, of existing low-energy Bluetooth transmissions ..."
Collins Radio Autotune Radio Advertisement
This advertisement for the Collins Radio 17D Autotune transmitters serves a couple purposes. The first and to me the most important is that it features the magnificent Douglas DC-3 twin engine commercial airliner. The military version, the C-47 Skytrain transport, was listed by Dwight D. Eisenhower as being among the four most important pieces of hardware (the others were the bazooka, the jeep, the atom bomb) that helped win World War II in the European theater. It dropped the paratroopers and towed troop gliders during the D-Day invasion. Interestingly, although Collins claims the 17D Autotune transmitters were widely installed ...
Sylvania Electric Duo Diode
When semiconductor devices first came onto the electronics scene, there was a lot of resistance (no pun intended) to adopting and designing them into circuits. Some of the reluctance (doh, another unintentional pun) was justified in that reliability could be an issue, due primarily to the mechanical contacts that interface wire leads to the semiconductor elements. In an effort to mitigate some of the fear of a new type of component, often times familiar names were given to them, such as with this duo-diode. Duo-diode vacuum tubes, the integration of two separate diodes into a single glass enclosure, were commonly used in balanced ...
Microsoft to Buy LinkedIn for $26.2B in Cash
"In a deal between companies that promise to unite "the world's leading professional cloud and network," Microsoft and LinkedIn have reached an agreement for Microsoft to pay $196 per share to acquire the professional networking service. That equals $26.2 billion or to put it in terms runners will understand, roughly one billion dollars for each mile of a marathon. The companies say that the deal has received the unanimous approval of both ..."
High-Q Tank Circuit for Ultra-High Frequencies
Ham radio operators who build their own equipment have never shied away from tackling leading-edge, technically challenging projects. Indeed, many Amateurs have pioneered radio circuit, antenna, and propagation concepts that were later adopted by military and commercial concerns. One of the first examples was the relegation of hitherto believed to be unimportant shortwave frequency bands for amateur radio use. Quite unexpectedly, Hams quickly took up the challenge and exploited the unique long range communications capabilities possible due to atmospheric channeling and reflection phenomena. Here, coaxial resonant cavities are used to ...
On-Chip Supercapacitors Dump Carbon in Favor of Silicon
"Tiny supercapacitors that can fit right on a chip have been hotly pursued for at least the last half decade. We've seen the usual suspects—graphene, titanium carbide and porous carbon—proposed for making the electrode material for these on-chip supercapacitors ..."
P1dB Releases Improved YouForm™ Conformable Cables
P1dB, an RF and Microwave component supplier, releases its improved YouForm™ conformable cable assemblies that can be built to an ultra low VSWR, such as 1.08:1, and at a comparable price to standard conformable cables. YouForm™ cables can also be phase matched to 1 degree, depending on the frequency and configuration. YouForm™ cable assemblies are available in 0.034 inch (0.86mm), 0.047 inch (1.19mm), 0.086 inch (2.18mm), 0.141 inch (3.58mm) and 0.250 inch (6.35mm) coax ...
Microwave Engineering Crossword Puzzle for June 12, 2016
For the sake of avid cruciverbalists amongst us, each week I create a new crossword puzzle that has a theme related to RF, microwave, electrical and mechanical engineering, mathematics, chemistry, physics, astronomy, mathematics, and other technical words. You will never be asked the name of a movie star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Enjoy! ...
Triad RF Systems Intros a 1.3-1.4 GHz 30 W BDA
The TTRM1081 is an L-Band bi-directional SSPA suitable for high data-rate wireless links. Applications include UAVs and military mesh networks. Rx noise figure is approximately 1.3 dB and Tx/Rx switching speed is 1 µS. This class AB LDMOS module is designed for both military and commercial applications. It is capable of supporting any signal type and modulation format, including but not limited to 3-4G telecom, WLAN, OFDM, DVB, and CW/AM/FM ...
Magnolia Radio Lab Ad - Would You Believe It?
A regular feature in the ARRL's magazine QST during the early days of radio was "New Receiving Tubes." It usually had your standard editorial listing of products, but the May 1941 installment included a comic commissioned my the Magnolia Radio Lab people that is done in the manner of Ripley's Believe It or Not. I'm guessing that there really is no Magnolia Radio Lab because nothing came up on a fairly extensive Internet search for the company. Most good humor has an element of truth in it that makes the subject matter believable - almost ...
Burgess Battery Advertisement
This could be a modern day photo of an American DHS or an Israeli IDF agent displaying a body bomb found on an attempted suicide bomber after thwarting an attack, but it's not. In actuality, it is a 1934 Burgess battery advertisement that appeared in QST magazine with the intent of demonstrating to Hams the kinds of research the company was doing. This design was called a 'ribbon battery,' and it could conveniently be wired in a flexible manner with almost any number of series and parallel connections to accommodate required voltage ...
Let's Use Neon Bulbs
Neon bulbs used to show up in lots of commercial, military, and consumer products, but have given way to LEDs because of efficiency in cost, size, weight, and reliability. The 1950s vintage radar I worked on in the USAF used lots of them as indicators. Before the availability of Zener diodes, they were used quite often as constant voltage references because of their characteristic of maintaining a fairly steady voltage value over a wide range of currents. One of the more useful tasks remaining for neon bulbs is for troubleshooting RF circuits because of their ability to glow in the presence of a strong electromagnetic field while only having physical ...
RF & Microwave Articles for June
Since the majority of people no longer receive paper copies of the magazines, I try to drive a little traffic to their websites by highlighting titles that appeal to my interest and like-minded RF Cafe visitors.
- 11 Myths About Antenna Design,
Southwest Antennas' New S-Band 2.1–2.5 GHz Body Worn Antennas
Southwest Antennas is pleased to announce the introduction of two new S-Band RHCP & LHCP patch antennas to their growing line of body worn antenna products. These two new products offer superior directional antenna performance over existing designs available on the market, and feature a best-in-class form factor that only weighs 1.3 ounces. Designed to be light weight and easily worn and hidden in tactical clothing, these body ...
Vintage Vacuum Tube Radio Data Service Sheets
I beg your indulgence again. Here are 4 more Radio Service Data Sheets for those who might be searching for such information as part of a restoration project. The Brunswick Panatrope was billed as the world's first all-electric phonograph (as opposed to the mechanical crank-up models), combined with an AM radio. It was designed with the assistance of RCA, many of whose components were integrated into the unit. A video of a restored Panatrope is embedded on the page. Brunswick Model 31 Combination Radio and Panatrope Radio Service Data Sheet, Stewart-Warner Series 900 Radio, Zenith 5-Tube Triple-Wave Superhet. Chassis nos. 5508 and 5509 Radios, Emerson Models 38, 42 and 49, 6-Tube Dual-Wave Super. (Chassis U6) Radio.
Sangamo Electric Company Advertisement
October 29, 1929, aka 'Black Tuesday,' is a date that will live in infamy. It was the beginning of the U.S. stock market crash that resulted in The Great Depression. Since magazines, particularly in the pre-digital era, went to press a month or two prior to hitting the postal system and store racks, almost nobody had any idea that by the time this issue of QST was being read, investors would be hurling themselves out of high rise building windows and off tall bridges. As the country was coming to grips with what would ultimately be a nearly two decade long financial struggle, nonessential creature comforts like concert quality recorded and broadcast music equipment like that facilitated by Sangamo Electric Company's ...
The Wavelength Factor
In this second part of a 3-part series, author Yardley Beers discusses propagation effects, modulation systems, and receiver techniques. A particularly interesting topic included in this installment is that of using a form of pulse modulation in FM broadcasting in order to exploit the 'capture effect' whereby a signal in the presence of noise will tend to suppress the noise. I don't think modern stations use that method, possibly because of incompatibility with stereo channels and data added for digital readouts ...
The Shack Is Back
Lou Frenzel, over at Design News, posted an article reporting on the - at least temporary - reemergence of the classic American electronics parts store Radio Shack, now formerly 'General Wireless Operations Inc. dba RadioShack.' Radio Shack, if you recall, filed for bankruptcy in 2015, and was bought by a hedge fund company. 1,700 of the original 4,000 brick-and-mortar shops were retained, and their online presence has been enhanced. The new management is hoping to exploit the growing Maker and DIY community as well as STEM education efforts. Read Lou's article and a follow-up here.
Able Signal Amplified Digital Outdoor HDTV Antenna Installation
Since I do not have time to watch television on a regular basis, paying for a cable or satellite subscription cannot be justified. My plan was to install a traditional FM/VHF/UHF television antenna on the roof along with a rotator. Some pretty nice models are still available from Channel Master, RCA, and a few others. TV broadcast stations in the Erie area are all within 10 miles or so, so signal strength would not be an issue. I listen to both AM and FM radio most of the day, so being able to get an FM signal boost from a steerable antenna would be a nice bonus since occasionally reorienting the FM dipole was needed to get a clear signal. The entire outfit would cost less than a year's ...
Television Set Shipments by Areas
According to a tally crafted by Radio & Television News magazine in 1949, the total number of television sets sold in the United States in 1947 and 1948 was 964,206. There were approximately 146 million people at the time per the U.S. Census. If there was an average of 4 people per household, that works out to around one television set for every 36 houses. Some households already had TV sets during that time, but far fewer than half owned a television. Nobody owned ...
Makerspaces & Maker Faires
DIY (do-it-yourself) is the relatively new term adopted to describe any activity engaged in by laymen and even professionals plying their trades after hours. Subjects range from hanging a kitchen cabinet or planting a tree, to a total engine rebuild or building a robot. Reasonable quality and capability tools for performing around-the-house chores are fairly cheap and available for purchase or rent for projects most people undertaking such challenges. Cordless saws and drills, stud finders, airless paint sprayers, and electronic readout levels can be had for under ...
Post Office Efficiency - Not
While on the subject of RF Cafe Book Drawing winners, you might find it interesting that that March 2016 winner, who lives in Canada, reported his book, which was mailed from Erie, PA, on April 18, finally arrived in Ottawa on May 22. It made its way to the Canada Post Office in three days, and then sat in Customs (per the online package tracking service) for more than a month! Books that have been shipped to Australia have gotten there in three weeks, and past books to Canada arrived in just a few days, so I can't imagine what took that one book so long in customs.
Portable Two-Way Radio Phone
This 1955-era photo of the "Portaphone" might be considered one of the world's first commercially available portable phones. It cannot be considered to be a cellphone in that there were no "cells" of transceiver stations capable of servicing sets moving between cell coverage boundaries. Early portable - or mobile - phones were serviced by a central tower that performed a relay service between the RF device (handset) and the local telephone service. The earliest of those systems, prior to automation, relied on a human operator to patch ...
VidaRF's High Performance SMD Circulators & Isolators for 0.3-3.0 GHz
VidaRF offers high performance "SMD" circulators and isolators with Low IMD covering the frequency band of 0.7-3.0 GHz. This rugged design uses a screwed in cover and machined housing. Units are fully tested to perform vibration, thermal shock and moisture making suitable for base station and other infrastructural environments. RoHS Compliant ...
Congrats to May 2016 Book Drawing Winner Ivor B. !
Ivor B., of San Diego, CA, is the lucky winner of my May 2016 Book Drawing. Ivor wisely selected Quantum Mechanics of Nanostructures, by Vladimir V. Mitin, Dmitry I. Sementsov, and Nizami Z. Vagidov. Each month I choose one or more names from people who have e-mailed to order RF Cafe software or to let me know about an error somewhere on the website. Ivor pointed out a typo in a capacitance quality factor equation. Two other people have been notified re winning, but have not responded. The book was graciously provided by Cambridge University Press.
Scott Adams Makes a Political Stand
Dilbert creator Scott Adams has often incorporated - albeit usually stealthily - his views on the economy, social mores, political correctness, or even pure politics for that matter within the comic strip. He recently posted an article on his blog titled "My Endorsement for President of the United States." When reading it, look for the nuances of his message, the same type skill needed to fully appreciate Dilbert, Wally, Alice, Dogbert, and Catbert. I believe I figured out his position on the upcoming election, which is not necessarily as it seems on the surface. What say you?
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