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 tying up your telephone line, and a nice lady's voice announced "You've Got
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4 of the December 2018 homepage archives.
Ham Comics: There's One in Every Crowd
It's the Friday before Christmas vacation and
nobody is thinking about work. If you are stopping by RF Cafe to kill time until the
boss lets you go home (early, preferably), thanks for thinking of us. Not that you really
need something to get you in a festive mood, but here are a few funny
amateur radio-themed comics from a 1966 issue of Popular Electronics magazine,
compliments of artist Buz Holland. When I saw the comic with the parrot squawking CQ
while including his call sign - WA4YKK - my first thought was to check the FCC's Universal
License System (ULS) to see to whom it belongs, and then I realized it was the artist's ...
Engineers Have High Hopes for Economy
Part 4 of Electronic Design's2018 Salary & Career Survey covers engineers' attitude about
the economic outlook of the nation. "More than 60% of respondents to Electronic Design's
latest annual Salary Survey have positive feelings about the status of the United States
economy, while around 15% feel negatively about it. Another 25% of the more than 1,300
survey respondents say they have no strong opinions about it either way. Only 3% harbor
very negative feelings about the overall economy. Electrical engineering represents one
of the economy's main engines. Semiconductor firms that supply parts for all sorts of
products are monitored for clues about the future of the American economy. The Trump
administration has had electronic devices in its crosshairs as it attempts to close a
trade imbalance with China ..."
Coil Function Quiz
Here is a quick, 10-question
electronics-themed quiz about coils (inductors). It appeared in the June 1962 edition
of Popular Electronics magazine. Don't be scared off by the vacuum tubes that
appear in three drawings. Just pretend they are transistors - it won't affect your answers.
One of the coil applications is almost obsolete for most people as the nature of computer
monitors and TV screens has changed significantly in the last decade ...
Navigating the 5G NR Standards
of Keysight Technologies, has an article titled "Navigating the 5G NR Standards" on the Microwave Journal
website that is an introduction to the increasingly complex topic of wireless communications.
Says Ms. DeTomasi "Approximately once each decade, wireless communications standards
have marched forward, advancing through 2G, 3G, 4G and now moving into 5G. The 5G New
Radio (NR) standard creates a whole new era of wireless communications. The promise of
everything connected, all the time, with extremely fast download speeds and ultra-low
latency will require massive changes across the 5G ecosystem. The 5G NR standard adds
new operating bands with advanced ways to package and transmit signals. mmWave operating
bands, wider modulation bandwidths, scalable numerologies ..."
Reindeer Really Do Know How to Fly!
For the past many years, videos have been
posted that confirm to all the
Doubting Thomases out there
Christmas Song" songwriters Bob Wells and Mel Tormé (popularized by Nat King Cole)
asserted. This story qualifies as a high tech subject due to the FHSS / DSSS techniques
in the 2.4 GHz ISM band radio systems, and brushless motors using LiPo batteries.
Merry Christmas to All, and to All a Good Night!
TotalTemp Technologies: Thermal
Platforms for −100°C to +200°C
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 ...
Shape-Shifting Origami Helps Antennas
Adapt on the Fly
"Researchers at the Georgia Institute of Technology
have devised a method for using an
origami-based structure to create radio frequency filters that have
adjustable dimensions, enabling the devices to change which signals they block throughout
a large range of frequencies. The new approach to creating these tunable filters could
have a variety of uses, from antenna systems capable of adapting in real-time to ambient
conditions to the next generation of electromagnetic cloaking systems that could be reconfigured
on the fly to reflect or absorb different frequencies. The team focused on one particular
pattern of origami, called Miura-Ori, which has the ability to expand and contract like
an accordion ..."
Electricity & Physiology
The subtitle of this article from a 1971 issue
of Popular Electronics, "From
Quackery to Speculation to Programmed People," could to some extent still be applicable
even though the author evidently meant to put an end to the "quackery" and "speculation"
part of it. Indeed, a lot of advancement has been made in the fields of electrostimulation
of weak or/or paralyzed muscles, healing of certain types of soft and hard tissues, suppressing
sporadic muscle twitching and epileptic seizures, and other malady diagnosis and relief.
Specifically tuned microwave frequencies have proven useful in healing and symptom relief
as well. As with most articles on medical procedures, I cringe at some of the photos,
like the "skin tunnel transformer" where an implanted subcutaneous coil ...
Wanted: Vintage LEDs for Historical Display
Website visitor Joshua Albright wrote to say he is
assembling a historical display of LEDs and wonders whether anyone out there has examples
from the 1960s through early 1980s. In particular, Monsanto, General Electric, Texas
Instruments, [Thorn], and Fairchild are the manufacturers he's most interested in obtaining.
"The things I typically look for [to identify age] are the can construction, gold plated
leads, epoxy with bubbles in it, and the lousy light output the early LEDs had." Mr. Albright
is offering to pay for useful LEDs and/or shipping costs if needed. If you are able to
help, please send me an e-mail
here at RF Cafe and I will put you in touch with him. Thanks for your help.
An Introduction to Interference
Rohde & Schwarz (R&S) has a pretty nice
white paper out titled, "An Introduction to Interference Hunting," which is free for downloading
(I always try to find links that do not require registration). It goes through basic
techniques of using a directional antenna for tracking down signals of interest. R&S
actually has quite a bit of information on interference location with their "iHunter Training Program" whereby you can become a certified Interference
Hunting Professional. Online training
videos are also available from R&S ...
is defined as the simultaneous visual reception of a multiplicity of radio signals over
a broad band of frequencies. In addition, panoramic reception provides an indication
of the frequency, type and strength of signals picked up by the receiver. Deflections
or 'peaks' appearing as inverted 'V's on the screen of a cathode-ray tube." It is the
kind of display that radar operators at Pearl Harbor were using when they mistook wave
of incoming Japanese bombers a squadron of B-17s from the mainland. The panoramic receiver
is not a wartime development, experimental models having been produced just prior to
the outbreak of war. However, the many uses to which it has been put have demonstrated
that the panoramic idea, particularly in the form of adaptors which may be connected
to any receiver, is going to be very important ...
Neil Carleton, VE3NCE, Named to Canadian
Amateur Radio Hall of Fame
Check this out:
Mr. Neil Carleton, VE3NCE, has been inducted into the Canadian
Amateur Radio Hall of Fame. Neil contacted me early this year requesting that I post
a notice of the upcoming auction for his immense
radio-themed postage stamp collection, which was a life-long passion. "Radio Amateurs
of Canada (RAC) says the honor recognizes radio amateurs' 'outstanding achievement and
excellence of the highest degree, for serious and sustained service to Amateur Radio
in Canada, or to Amateur Radio at large.' RAC said Amateur Radio played an important
role during Carleton's teaching career, and he was a key advisor in developing the RAC
Youth Education Program, aimed at introducing Amateur Radio in the classroom. Carleton
is a member of the Almonte Amateur Radio Club ..."
Transient Specialists: EMC, EMI,
RFI Test Equipment Rentals
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 ...
Topological Material Switched off &
on for 1st Time
"Over the last decade, there has been much excitement
about the discovery, recognized by the Nobel Prize in Physics only two years ago, that
there are two types of insulators: normal insulators which don't conduct electricity,
and topological insulators - newly discovered materials that conduct electricity only
on their edges. Now, FLEET researchers at Monash University, Australia, have for the
first time successfully 'switched' a material between these two states of matter via
application of an electric-field. This is the first step in creating a functioning
topological transistor - a proposed new generation of ultra-low energy
electronic devices. Ultra-low energy electronics such as topological transistors would
allow computing to continue to grow, without being limited by available energy as we
near the end of achievable improvements in traditional ..."
National Company Christmas
and New Year Greeting
Take a look at the list of National Company's
employee list wishing their customers a
Merry Christmas and a Happy New Year. Every one of them is a licensed Ham radio operator.
It appeared in the January 1941 issue of QST, but was for the 1940 Christmas.
National Company was a major producer of amateur radio gear in the day. Little did they
suspect that by the same time a year later, America would be newly engaged in World War II
after the Japanese attack on Pearl Harbor on December 7, 1941. Interestingly, the American
Lung Society's Christmas Seals stamp that appears in the upper left corner is authentic
and must have been applied by humans. That means thousands of copies had to be manually
stamped before mailing ...
Just in Time for
Christmas Package Thieves: A Glitter Bomb
This video has gotten more than 25 million views
in just two days. NASA engineer Mark Rober decided to reward the human debris who steal
packages from people's porches. His
is a technical marvel of CAD design, 3−D printing, smartphone GPS location tracking
and video streaming, custom PCB, mechanization, and microprocessor control. You'll have
a great laugh at watching the reactions of low life scum who take the bait. GPS tacks
the perp, and then when he / she opens the box a swirling mass of multicolor glitter
is spewed all over the place. As if that is not enough, a few seconds later Fart Gas
(redundant?) is sprayed to enhance to mood during clean-up of the glitter mess. Mr. Rober
is no newcomer to such pranks, as his other videos show. I'm surprised he hasn't been
sued yet. Surely there's an
ambulance chaser out there looking for an easy buck - and a deranged
judge to match ...
Anatech Electronics 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: a 10-1000 MHz, 2-way power divider with
SMA connectors, a 113 MHz bandstop / notch filter with SMA connectors, and a surface
mount, 5000 MHz ceramic bandpass filter. Custom RF filters designs are used when a standard
cannot be found, or the requirements are such that a custom approach is necessary ...
Klystron: Tube for Outer Space
If you have been in the RF and microwaves business
for any length of time, you are probably familiar with a company named Varian. In the
days before you did your parts shopping online, Varian catalogs populated the desks and
bookshelves of many RF engineers who worked in the radar field, including mine. Did you
know that it is named after the brothers Russell and Sigurd Varian, who started the business
in 1948 to market their high power
klystron tubes? Following a number of reorganizations, it was purchased by Agilent
technologies in 2010. This story from Radio Electronics magazine does a real
nice job explaining the workings of a klystron without getting too deep into the gory
theoretical detail ...
Nova Microwave: RF & Microwave Circulators &
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. Please
visit Nova Microwave today ...
Researchers Perform Analog, Wave-Based
Computations Using Wi-Fi Signals
"A pair of French researchers have developed a
way to use ordinary Wi-Fi signals to perform analog,
wave-based computations. Researchers, Philipp del Hougne and Geoffroy
Lerosey, from Langevin Institute and the company Greenerwave, have described their
experiments and what they represent, in their paper published in the journal Physical
Review X. Computers represent information digitally, in ones and zeroes - but back in
the early days of computing, there was discussion regarding the possibility of using
analog processors. Even then, it was clear that such an approach would be less energy-intensive.
But digital won out, and the rest is history. But that might not be the end of the story.
As hardware engineers begin to run headlong into the limitations of Moore's Law, some
engineers have begun ..."
Ulano Masking Films - Rubylith
Raise your hand if you're old enough to remember
doing printed circuit board layout using
Rubylith tape. My hand is up. Back in the early 1980s, I did prototype PCB designs
in an engineering development lab at Westinghouse Electric's Oceanic Division. Most of
it was for analog and RF substrates that would be photographically reduced in size for
use with bare integrated circuit die and surface mount passive components (Rs, Ls, and
Cs), upon which I would later epoxy-mount those components and wire-bond everything using
1−mil gold wire. However, there were projects where full-size leaded components
were used on a through-hole PCB that used not only the Rubylith tapes but also sheets
with special electronics shapes for solder pads around the holes for components leads,
ground and power planes, board-edge connectors ...
Chip with Micro-Hotplate for Self-Healing
and Sustainable Electronics
"This invention is an
on-chip immune system against hot-carrier stress, bias temperature
instability, and total ionizing dose degradation. Ames Research Center, Moffett Field,
California Heat treatment, also known as annealing, is a common step in the semiconductor
fabrication process. A buildup of radiation-induced localized charge within the semiconductor
and insulator alters local field distribution, threshold voltage, and leakage current.
NASA's patent-pending technology implements an annealing process on a system level directly
on a chip for annealing defects and improving device performance with heating done in
the laboratory. The annealing may be performed inside an oven or upon a hotplate ..."
Please Visit Triad RF Systems to Thank Them
for Their Support
Triad RF Systems designs and manufactures
RF power amplifiers and systems. Triad
RF Systems comprises three partners (hence 'Triad') with
over 40 years of accumulated knowledge of what is required to design, manufacture, market,
sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA, bi-directional,
and frequency translating amplifiers are available, in formats including tower mount,
benchtop, rack mount, and chassis mount. "We view Triad more as a technology partner
than a vendor for our line-of-sight communications product line." Please check to see
how we can help your project ... Please
check to see how they can help your project ...
Too-Small Cubicles: 1932 "The Wireless World" Article
As the old saying goes, "The more things change,
the more things stay the same." Incredibly, back in 1931 people were complaining about
shrinking office cubicle sizes. To wit: "At 'Broadcasting House' rooms measuring
8ft. x 6ft. are being coveted by the many people who will be condemned to labour in cubicles
7ft. x 5ft. The Civil Engineer himself, who helped to design and erect the building,
works in a compartment in which, as the American said, 'You couldn't cuss a cat without
getting hair on your teeth.'" ...and whoa!, dig this statement by the author regarding
the demise of "local oscillators" in the UK (noisy regenerative Rx LO interference):
"Steps might be taken to ensure the survival of a few specimens, perhaps by the founding
of a national reservation similar to those which accommodate the Red Indians in America.
The few remaining squealers and their ..."
PCB 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 (e.g., material, flexible, rigid), Geographical
location, and more ...
Topological Matters: Toward a
New Kind of Transistor
"Billions of tiny transistors supply the processing
power in modern smartphones, controlling the flow of electrons with rapid on-and-off
switching. But continual progress in packing more
transistors into smaller devices is pushing toward the physical limits
of conventional materials. Common inefficiencies in transistor materials cause energy
loss that results in heat buildup and shorter battery life, so researchers are in hot
pursuit of alternative materials that allow devices to operate more efficiently at lower
power. Now, an experiment conducted at the U.S. Department of Energy's Lawrence Berkeley
National Laboratory has demonstrated, for the first time, electronic switching in an
exotic, ultrathin material that can carry a charge with nearly zero loss at room temperature ..."
Meet Mr. FET ... the Transistor That Thinks It's a Tube
Yesterday was the 71st anniversary of the announcement
of the transistor's invention by Drs. Shockley, Bardeen, and Brattain at Bell Labs, but
it was a Sunday so not as many RF Cafe visitors saw the commemorative title graphic I
used. Their transistor was a current-controlled signal amplifying device as opposed to
field-effect transistor (FET) which is a voltage-controlled signal amplifying device
- as is the vacuum tube. I never thought about it before, but maybe that had something
to do with the electronics world's hesitancy to adopt the transistor as a replacement
for the tube. Early in the transistor's history, practical applications were limited
due to low reliability, low power handling, low frequency, lack of ruggedness in harsh
operating conditions, and other shortcomings compared to established and much refined
vacuum tubes was reason enough to shun the newfangled technology, but that current-controlled
5 Ws of Spray-on Antennas
"Spray-applied MXene antennas could open the door for new applications
in smart technology, wearables, and IoT devices. This method sprays invisibly thin antennas
- made from a type of two-dimensional metallic material called MXene - that perform as
well as those being used in mobile devices, wireless routers, and portable transducers.
MXene titanium carbide can be dissolved in water to create an ink or paint. The exceptional
conductivity of the material enables it to transmit and direct radio waves, even when
it's applied in a very thin coating. Even transparent antennas with thicknesses of tens
of nanometers are able to communicate efficiently. The thinnest antenna was 62 nanometers ..."
Lenny & the Squigtones - "The Jolliest Fat Man"
Most people who were around in the 1970s remember
the sitcom "Laverne &
Shirley." It was popular as a part of the whole 1950s renaissance that was happening
with shows like "Happy Days," "Grease," "American Graffiti," et al, that captured the
attention of the parents of we teenagers as well as weselves [sic]. I was being
held against my will at Southern Senior High School at the time, and many of the kids
adopted a "greaser" lifestyle that included cigarette packs rolled up in t-shirt sleeves
and Brylcreem in the hair (mainly just the guys), leather jackets and Keds high-top sneakers
(guys and gals), and poodle skirts and saddle Oxford shoes (mainly just the gals). Two
weirdo characters, Lenny and Squiggy, made cameo ...
At the 1929 Radio World's Fair
You've heard of the World's Fairs, the most familiar
probably being the 1933 Chicago World's Fair where the theme was "A Century of Progress."
World's Fairs have been held in various cities worldwide since the late 1790s. In 1929,
the World's Fair was held in the United Kingdom, but the "Radio
World's Fair," which began its annual run in 1924 (click on
stamps thumbnail), was held in New York City. Surprisingly little exists on the
Internet about the events. It was more of a trade show to introduce new products than
it was a fair, as can be seen from the photos. Radios with decorative wooden cabinets
were becoming popular as the number of commercial broadcast stations was growing rapidly.
Remote control in the day meant a handheld unit with a cable attached to the main system.
Crosley introduced its first gendered radio model - the Monotrad ...
Empower RF Systems: RF & Microwave Power
Empower 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
RFID Patent Enables Increased Bit Density &
Lowering Costs of Tags
"Vubiq Networks has filed its fourth millimeter
wave RFID patent application with the U.S. Patent and Trademark Office. The application
is entitled System and Method for High-Bit Density Millimeter Wave Chipless RFID and
has been assigned the application number 62775479. The patent application defines advanced,
high-bit density chipless RFID technology using the company's polarimetric synthetic
aperture radar (SAR) technique that incorporates polarization and phase detection. The
technology will provide orders of magnitude higher bit density for RFID tags as compared
to 'prior art' or other competitive approaches. The application, which is the fourth
RFID patent ..."
RF Cafe Engineering & Science Crossword Puzzle December
Each week, for the sake of all avid cruciverbalists
amongst us, I create a new
technology-themed crossword puzzle using only words from my custom-created lexicon
related to engineering, science, mathematics, chemistry, physics, astronomy, etc. You
will never find among the words names of politicians, mountain ranges, exotic foods or
plants, movie stars, or anything of the sort. You might, however, see someone or something
in the exclusion list who or that is directly related to this puzzle's theme, such as
Hedy Lamarr or the Bikini Atoll, respectively. This week's crossword contains a shameless
plug for my custom software products - they're inexpensive and will save you a lot of
Please Support RF Cafe by purchasing
my ridiculously low−priced products, all of which I created.