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...
All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.
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.
See Page 1 |
4 of the November 2019 homepage archives.
Receiving "Explorer's" Radio Signals
Amateur radio operators who engage in
satellite communications by now are very familiar with needing to compensate
for Doppler frequency shifts. Author D. Ripani writes in this May 1958 issue
of Radio & TV News magazine how he was caught off guard by the need
to compensate for relative motion between the satellite and his fixed receiver.
He needed to continually readjust while tracking the Explorer 1 satellite. Nowadays,
many (probably most) Hams use software to automatically track and tune transceivers
based on readily available ephemeris data published on orbital paths. Due to elliptical
orbits that vary in altitude above the Earth's surface, the Doppler shift is not
a constant for any satellite. Mentioned is the calculated Doppler shift of ± 2,900 Hz
based on Explorer's orbital speed of about 18,000 mph. The included screenshot
is from my RF Cafe Calculator Workbook (free download) Doppler Shift calculator ...
2019 Asia-Pacific Microwave Conference
2019 Asia-Pacific Microwave Conference (APMC)
will be held from December 10th through 13th in Singapore. "APMC dates back to 1986
in New Delhi, and it is now recognized as one of the premier international conferences
of microwave community. Singapore is proud to organize the 2019 APMC. This event
will continue the spirit of APMC, address important issues in the microwave community
to exchange results and discuss collaboration. 2019 Asia-Pacific Microwave Conference
(APMC) will offer a rich scientific program of the highest quality with invited
speakers from all over the world and provide a broad forum of exchange for both
academia and industry alike. The conference will cover the entire scope of microwave
and millimeter wave engineering ..."
Kuwait Now Building Integrated Circuits?
A friend of our family who is a captain in
the U.S. Army Reserve has just been deployed to Kuwait for a year. While researching
some information about Kuwait, I ran across this image that appears to be a close-up
of an integrated circuit built there. Lighting effects from the top SiO2 passivation layer makes fine detail difficult,
but the topology is typical of
mixed analog and digital ICs, with a rather large
memory section on the left side. A 5G smartphone device? My guess is the dark square
area at center bottom is the I/O steering circuitry. A couple large FETs appear
in the upper right corner, and the 6 printed spiral inductors below them could be
impedance matching inductors if this is some sort of RF interface. I am no expert
on IC layout, but this seems to be a pretty crappy design - certainly no competition
for Qualcomm. A hyperlink to the image source is included, so maybe you can do a
better job of discerning the chip's function ...
Simpson Electric Company Model 260 Advertisement
I was first introduced to the
Simpson 260 volt-ohmmeter (VOM) in the radar shop where I was assigned un the
USAF. Here is the modern version of that classic, the Simpson 260-8 VOM; it looks
a lot like the original. Here is an advertisement that I scanned out of my copy
of the July 1944 QST magazine. It highlights the precision to which its meter movement
pivots are manufactured. "While Simpson Electric Company, chartered in 1934, is
a firm with a distinguished past, it is just as importantly an organization with
a dynamic present and a definite future." There is an entire website dedicated to
the history of the Simpson 260. The famous 260 Volt-Ohm-Milliammeter put Simpson
on the map and cemented a reputation for quality that still defines Simpson in the
marketplace today." You can still buy a brand new Simpson 260 (-8) from Amazon,
or grab a vintage ...
Many Thanks to KR Electronics for
Helping Deliver RF Cafe!
KR 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.
Three-Dimensional, Curved Electronics
"The manufacturing method produces
curvy electronic devices such as wearables, contact
lenses, solar cells, and optoelectronics. Electronic devices are typically manufactured
in planar layouts but many emerging applications require three-dimensional curvy
structures. Fabrication of such structures has proved challenging due to the lack
of an effective manufacturing technology. Existing manufacturing technologies, including
micro-fabrication, don't work for curved, three-dimensional electronics because
they are inherently designed to produce two-dimensional, flat electronic devices.
These devices are small - ranging in size from millimeters to centimeters ..."
ERZIA: Microwave & mm-Wave
ERZIA serves critical aerospace and defense
missions by designing and manufacturing RF, microwave,
and mm-wave amplifiers, integrated assemblies operating from low frequencies
up to 100 GHz, and by providing high reliable satellite communications. The
company was founded in 2002 to become a worldwide reference of advanced engineering,
performance, reliability and ruggedness. Their catalogue of standard amplifier modules
comprises more than 100 different models, having also a high capacity of customization
for amplifiers and integrated assemblies. Some of products have space heritage and
are used in aerospace, commercial, military and scientific systems, having a wide
range of final applications.
Silicon Solar Cells
As with most technologies,
solar cells have come a long way in the last half century. Fabrication processes
and efficiencies have improved significantly, motivated highly in the last twenty
years or so by the global push to replace fossil fuels with other forms of power*.
This article from a 1973 issue of Popular Electronics magazine is a snapshot
of state of the art solar cells at the time. In the 1970s, there were no large scale
solar cell arrays that were a critical part of an electric power grid. Ditto for
wind turbines. One of the most significant uses of solar cells then was for powering
satellites that operated near enough to the sun to generate useable energy (out
to about Mars' orbit). Due to the relatively low output capacity, nuclear power
supplies provided electricity for higher demand nearby loads and for deep space
probes. A radioisotope thermoelectric generator; i.e., nuclear, powered the lunar
rovers for Apollo astronauts. Yep, we left plutonium 238 on the moon ...
Electricity in Motion: Current, Basic Navy Training
One of the Notable Tech Quotes which has
appeared on RF Cafe is, "The nice thing about standards is that you have so many
to choose from," by computer scientist Andrew Tanenbaum. In the middle of the last
century, a change in the fundamental understanding of current flow precipitated
what has become a very large opportunity for people to misunderstand descriptions
current direction caused by a difference in voltage potential (voltage) - depending
on the era a particular description was written. Beginning with Benjamin Franklin,
electron current flow was assumed to be from positive to negative, ostensibly but
incorrectly, because a positive thing must contain an excess of something (charge
carriers - electrons) and a negative thing must have a deficiency. Hence, current
flowed from an excess source to a deficient sink. We now know that negative things
contain more electrons (relatively) than a positive thing. "Conventional current"
is defined as charge carriers ...
Notable Tech Quote - Standards
"The nice thing about standards is that you
have so many to choose from." - Andrew S. Tanenbaum, Computer Networks, 2nd edition, page 254.
Helping to Eliminate the Mix-up over
Custom MMIC, a premier fabless RF and microwave
MMIC designer company, just published a very nice whitepaper entitled, "Helping to Eliminate the Mix-up over Mixers."
It begins thusly, "As Custom MMIC releases its first subharmonic mixers, we in the
Applications Group thought it was important to explain some of the benefits of working
with these products over fundamental mixers, particularly when mixing at very high
frequencies. First, we should take a minute to explain these two types of mixers.
A fundamental mixer combines an input RF signal, typically received via an antenna
or a prior mixing stage and multiplies it with a fixed local oscillator (LO) signal.
The LO signal is typically much higher in power level, as this signal provides the
energy for the mixer to combine the two signals in an efficient fashion. The output
of the mixer ..."
Baba's Amateur Weather Website Added
Yatharth (Baba) Verma, VU3NUF, wrote to request
that his webpage be added to my listing of
Weather websites. "NOAA satellite images are updated four times daily, on the
website, both as individual maps and a composite map. The satellite name, date &
time of pass, direction and maximum elevation, are all displayed in the map image
table. A chart showing the next available overhead passes of the weather satellites,
along with their downlink frequencies is also displayed on the website for reference."
Baba's station use an R820T2 RTL-SDR (software defined radio), connected to a homebrew
QFH (quadrifilar helix) antenna. The DSP application "SDR Sharp" is run in conjunction
with Orbitron, a satellite tracking software for automatic tracking of NOAA satellites,
on a PC running Windows 8.1. Once a satellite image is downloaded a satellite decoding
software WXtoImg is used to decode and publish it on the website. ...
HyperStealth Biotech Cloaking
"HyperStealth Biotechnology Corp. announces
their four patent applications which are all related to their Quantum Stealth (Light
Bending Material), otherwise known as the
Invisibility Cloak. The information within the
four patents has been released by Hyperstealth Biotechnology Corp. with over 100
minutes of videos demonstrating the prototype materials which are available to watch
directly from their website. Hyperstealth's Guy Cramer, President / CEO, is also
the inventor of the four patent applications. The first patent application is Quantum
Stealth, light bending material. True invisibility was thought to be impossible
by most physicists. Not only does the material hide a target in the visible spectrum ..."
Many Thanks to Centric RF for Their Continued
Centric RF is a company offering from stock
various RF and
Microwave coaxial components, including attenuators, adapters, cable assemblies,
terminations, power dividers, and more. We believe in offering high performance
parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power
levels from 0.5-500 watts are available off the shelf. Order today, ship today!
Centric RF is currently looking for vendors to partner with them. Please visit Centric
A 12,000 Tube Electron Brain
This Radio-Craft magazine article
starts out stating, "A skilled mathematician with a desk calculator requires four
years to do what the
IBM Calculator does in eight hours." That was in 1948. Just last month a headline
read, "Given the task of finding a pattern in a seemingly random series of numbers,
Google's quantum computer produced an answer in 3 minutes and 20 seconds. It estimates
that the Summit supercomputer here at the Oak Ridge National Laboratory in Tennessee
would take 10,000 years to complete the task. The IBM 12,000 vacuum tube computer
performed its calculation for an improvement factor of [(3 yr • 8760 hr/yr)
+ (1 yr • 8784 hr/yr)] ÷ 8 hr = 4383 (4.383 thousand). The Google
quantum computer performed its calculation for an improvement factor of (10,000 yr
• 31557600 s/yr) ÷ 200 s = 3.15776E11 s ÷ 200 s =
1.57788E9 (1.57788 billion -- or milliard) ...
A Few Funny Electronics Photos
RF Cafe visitor Gary S. sent me these
images that take a light-hearted poke at some technology-themed items. I included
hyperlinks to copies of the I found on the Web. The soldering iron pic had the title,
"How to tell when they got a model for the photo instead of a worker." The next
actually appears on the Bernard Food Industries' website. Then, the Mandor website
includes "Join the Resistance" among its many other comics. Finally, there is the
T-shirt with the inscription, "It's okay if you don't like Ham Radio... It's kind
of a smart person hobby anyway."
Berkeley Nucleonics Corporation (BNC) is
an established test equipment company having served the industry for 55 years. With
headquarters in San Rafael, CA, Berkeley Nucleonics is looking for a highly motivated
RF Instruments Sales Engineer to increase the company's U.S. market presence
and support sales growth in the U.S. and Canada. BNC offers RF signal generators
and synthesizers up to 40 GHz and phase noise test instruments. Responsibilities
include: Support a network of independent sales representatives on RF signal generator
sales, support and grow the company's house accounts in RF equipment sales, understand
customer needs and develop solutions with engineers involving ...
Standing Waves on Transmission Lines
In this article from a 1942 issue of
QST magazine, author T.A. Gadwa employs a
standing wave mechanism analogy that I don't recall having read before - that
of a dam on a river. The river is the transmission line with a lake as the source
(presumably) and then he imagines a dam load. The dam standing waves, per his description,
have phase and amplitude characteristics that depend on how tall the dam wall is
relative to the surface height of the dammed river. An extensive array of graphs
is provided showing how the current of the dam standing waves react to the dam transmission
line termination impedance. I always wonder when seeing electrical-mechanical parity
examples whether, as with this case, there are any dam magazine articles out there
that use an electrical transmission line to help fellow civil engineers ...
Please Visit Empower RF's Website in
Appreciation of Their Support
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 levels.
RF Cascade Workbook 2018
RF 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 ...
Anatech Electronics November
2019 Product Update
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. In their November
Product Update, Anatech has introduced a surface mount 5G/LTE Band 66
/ extended AWS band downlink ceramic bandpass filter, a 5G / LTE Band 48 / CBRS
Band cavity bandpass filter with N-type connectors, and a 5G/LTE frequency Band
30(WCS) / Band 41 / Band 66(Extended AWS) /Band 71 multiplexer with N-type connectors.
Custom RF power directional coupler designs can be designed and produced when a
standard cannot be found, or the requirements are such that a custom approach is
New Carbon as Hard as Diamonds
"University of Buffalo (UB) researchers have
used a computational model to identify 42 new forms of superhard, stable carbon
materials that have potential for use in a range of applications. The researcher
said that some of the carbon materials they've discovered may be nearly as hard
harder than diamonds, making them well-suited for creating new
scratch-resistant coatings or developing new solutions to keep valuable objects
safe from damage. Hard materials are very useful to scientists, not just for the
development of commercial applications, but also for use in the lab, especially
in chemistry and materials science. Currently, diamond is the hardest material that
is available to researchers ..."
Thanks to Transient Specialists
for Continued Support!
Transient Specialists specializes in
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
Editorial - Engineering Enrollments Down Sharply
The origin of the phrase "Everything
old is new again" is credited to everything from the Bible to Shakespeare to
Mark Twain. It might be one of the most oft-repeated statements. The topic of this
editorial from a 1972 issue of Popular Electronics is a prime example of
why people like me invoke the aforementioned dictum. For as long as I have been
aware of the state of engineering and technology, opinion writers (aka "journalists"),
have lamented the sorry state of education in that it cannot motivate and produce
a qualified new crop of replacement engineers, scientists, technicians, doctors,
nurses, chemists, and other white collar workers (I can't recall ever hearing of
lawyer shortage, unfortunately). Looking back at how the "shortages" have been handled ...
AC Battery Incorporates a Biode
not a practical joke, after all, it won a NASA award. An
AC battery really has been invented - sort of. Although not
much detail is provided, it appears this "AC" battery is basically two batteries
back-to-back with a "biode" betwixt them and a semiconductor switch that cycles
from positive to negative polarity. The diagram indicates a sinewave, but maybe
it's a squarewave or something in-between. It's pitched as the second coming of
batteries. It would be nice to have such a device available, but will the reliability
be as good as existing DC cells given the added complexity? Time will tell.
Free Engineering Magazines &
of new titles are included this month.
pamphlets, books, magazines, and chapter examples listed here are a small sample
of a lot of new items that are offered for FREE through TradePub. The publishers
make them available to qualifying people as a promotional campaign for their full
line of offerings. Free e-books like "Maximizing LinkedIn for Business" and "20
Questions You Should Never Ask in an Interview" are examples. Magazine titles include
Microwave Engineering Europe, Electronic Design, and Microwave Product Digest ...
Electronic Component Checking (L, C, and R)
When this article on component (resistor,
capacitor, and inductor) measurement was written, readily available, inexpensive
multimeters were not in existence. For about $20 you can now buy a brand new
handheld DMM that will make very accurate resistance measurements and reasonably
good capacitance measurements at frequencies up to a few MHz, where lead inductance
starts to be significant (test frequency is usually only a few kHz). Finding an
affordable, accurate inductance meter is another story. Cheap LCR meters can be
purchased on eBay, but don't be surprised if the quality is not very good. The most
accurate measurement method uses a frequency in the realm of actual operation, and
this article ...
Custom MMIC Intros a GaAs
DC - 20 GHz Distributed Amplifier
Custom MMIC is proud to introduce a new
GaAs Distributed Amplifier operating in the popular DC - 20 GHz frequency
range, targeting Instrumentation and EW applications. The CMD244K5 offers very flat
gain and low noise figure across the band. This MMIC also has high P1dB and IP3,
yielding a high dynamic range. All this performance is neatly integrated in a small
5mm x 5mm plastic air-cavity surface mount QFN package. This new, high performance
distributed amplifier continues Custom MMIC's aggressive efforts to deliver the
best performing GaAs and GaN MMICs in the industry ...
The Growing Problem of Space Debris
"For sixty years, humans have been launching
things to space, giving rise to the problem of 'space junk.' If something isn't done about it
soon, the situation is going to become very messy! In 1958, the Space Age officially
began with the launch of humanity's first artificial satellite - known as Sputnik
1. Constructed and orbited by the Soviet Union, this satellite was a simple technology
demonstrator designed to emit radio pulses. However, the impact its deployment had
was much more far-reaching than that. Not only was this a pivotal moment in the
history of human spaceflight, and a big scare for the West, it was also the first
of thousands of satellites to be launched from Earth ..."
Triad RF Systems: RF/Microwave Amplifiers
and Amplifier Systems
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 they can
help your project.
Channel Master Antenna Advertisement
Channel Master is one of the few television
and FM radio antenna companies that has survived the evolution from over-the-air
(OTA) broadcasting to cable-based and then Internet-based broadcasting. Up until
around the end of the last century - which is incredibly two decades ago - a large
number of people still relied on rooftop and set-top antennas for program reception.
Airwaves continued to get more crowded both due to additional stations being built
and the ambient noise level increasing due to many other lower power devices in
use. An increasing number of manmade obstacles that blocked and/or reflected signals
resulted in many more low signal strength pockets and areas plagued by multipath
signal variability compounded the problem ...
Systems to Broaden Wearable Apps
"Imagine a handheld electronic gadget that
can soften and deform when attached to our skin. This will be the future of electronics
we all dreamed of. A research team at KAIST says their new platform called 'Transformative Electronics Systems' will open
a new class of electronics, allowing reconfigurable electronic interfaces to be
optimized for a variety of applications. A team working under Professor Jae-Woong
Jeong from the School of Electrical Engineering at KAIST has invented a multifunctional
electronic platform that can mechanically transform its shape, flexibility, and
stretchability. This platform, which was reported in Science Advances, allows users
to seamlessly and precisely tune its stiffness and shape ..."
Many years have passed since I sat in a college
classroom to learn about
transistor fundamentals. The industry had long moved past germanium transistors
and was solidly into silicon. Having been formally introduced to transistors in
the USAF, I was familiar with their functionality from a technician's perspective
of checking for gain, proper bias (as indicated on "educated" schematics), and determining
go-no-go health by performing a front-to-back resistance measurement using an ohmmeter.
Holes, energy bands, gate widths, and doping levels were first encountered in solid
state physics class, however. This article does a nice job of introducing the terms
and concepts at a layman's level. I actually found the vacuum tube circuits in our
radar unit easier ...
Berkeley Nucleonics Needs
an Electronics Technician
Berkeley Nucleonics Corporation (BNC) is
an established test equipment company having served the industry for 55 years. With
headquarters in San Rafael, CA, Berkeley Nucleonics is looking for an
Electronics Technician for test & measurement equipment with component level
experience. Job requires troubleshooting and calibration of analog and digital designs,
as well as some high voltage circuitry. Duties and responsibilities include: Repair,
test, and calibrate TTL pulse and delay generators with considerable analog circuits,
RF signal generators, microwave receivers, spectrum analyzers, some laser and high
voltage work. Provide technical support to customers through email and phone ...
Veterans Day 2019: A Pittance of
This is my annual
Veterans Day tribute. On November 11 (the 11th day of the 11th
month), at 11:00 am (the 11th hour), we observe 2 minutes of silence in honor of
countrymen who "gave the last full measure of devotion."
A Pittance of Time is performed by Canadian citizen
Terry Kelly(he went blind at an early age). It was written after
an experience he had on Veterans Day in 1999. It is done in the finest Celtic tradition.
everythingRF: Their Name Says It All
Please take a few moments to
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.
RF Cafe Radio Engineering Veterans Day Crossword
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.
This one for November 10, 2019 celebrates Veterans Day. 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 ...
Mercury Transit on Monday, November
Mercury will pass across the face of the
sun. The astronomical term is "transit." What makes this
transit of Mercury so spectacular is that it
passes nearly in the center of the sun. It will take Mercury approximately 5-1/2
hours to move from the eastern edge to the western edge, from 7:35 am to 1:04 pm
EST. Both the sun and the moon subtend an angular width of about half a degree.
Of course will should never look directly at the sun with your naked eyes, and particularly
not with any sort of magnification, be it binoculars or a telescope. The safest
way to observe this Mercury transit it by using a white projection screen with any
telescope generate an image large enough to make the black dot of Mercury stand
out relative to the sun. Weather permitting, I'll have my 1969 era 60 mm
Sears Model 6305A refractor set up. The next
transit of Mercury will be in 2032!
Footer - RF Cafe
Right Border Content - RF Cafe
Please Support RF Cafe by purchasing
my ridiculously low−priced products, all of which I created.