|
 If you are like me, you spend a lot of time
reading articles from technical magazines. Sometimes I read the entire article,
but usually I just scan the text for highlights and look at the schematics, block
diagrams, and charts / graphs. Often, I want to go back and find an article but
cannot recall where I saw it. A Google search will usually eventually reveal a hyperlink
to the article, but a lot of times it takes a lot of digging. Since my key interests
are not necessarily the same as RF Cafe visitors, an attempt will be made to catalog
all of them. If there is a magazine not included here that you would like me to
include in the list, please send me an e-mail and I will try to incorporate its
articles, too.
Aerospace & Defense | EDN | Electronic Design |
High Frequency Electronics |
IEEE Spectrum | Microwave Journal | Microwaves &
RF | Microwave Product Digest |
 Many of us are familiar with
the math behind the Smith chart. Some have written spreadsheets
and software for creating Smith charts, if only for the satisfaction of being able
to do so. It really is quite simple (complex, actually - get it?) to do, but as
with most things a genius mind (i.e.,
Phillip Smith)
was needed to think of doing it in the first place. John Dunn, a very smart guy
in his own right, posted a good primer on the subject on the EDN website.
If you are new to the Smith chart or just want to do a refresh, then surf on over
to read his article, and maybe click on the three related links at the bottom for
more info.
 Here's a trip down Memory (640 kB) Lane
for those of us around during the early PC days, using MS−DOS. EDN magazine
has been running their column "Tales from
the Cube" (a take-off of the equally long ago "Tales from the Crypt" TV show)
where readers submit sagas of (usually) troubleshooting experiences. Most often
the problem is the result of an intermittent event or of human error (pronounced
"stupidity"). This is a case of the latter. If you fondly recall the times when
256-color VGA CRT monitors,
3½" floppy disks, 20 MB hard drives, and an
i80287 math
coprocessor were to die for, when you were deemed a computer expert if you could
write batch files, and half your computer's CPU power was not consumed by antivirus
programs (no WWW, just
Kermit
for local net access), then you might like this "The Mysterious
MS-DOS Reboot" anecdote by Robert Yankowitz. Enjoy!
 Whenever I see John Dunn's name I think of
the English poet John Donne, but that's my problem. Mr. Dunn wrote an article
for EDN magazine entitled, "What's the Difference Between EMF and Voltage?" He begins: "I
once read this very strongly-written essay about the difference between electromotive
force (EMF) and voltage. The author seemed like he was on some kind of holy crusade
and was intensely determined to set his readers straight on fundamental truths that
were NOT to be dismissed by infidels. I read his words, but for all of the vitriol,
I didn't understand him at all. Recently, I decided to take a closer look at the
issue. EMF is given in units of joules per coulomb. The frame of reference for this
definition is for any device that uses a non-electrical source of energy to impart
electrical energy to a unit of charge, which if given the chance, will flow somewhere..."
 James Mazzei has a good primer entitled,
"A
Reminder: Pay Attention to Harry Nyquist and Claude Shannon," on information
theory at the Electronic Design website, where he admonishes that, "Many
CIOs, CTOs, and architects tend to forget this telecommunications throughput issue."
Further, "It's a very easy and normal thing to focus on the principal characteristics
of the principal components of a communications system or link, and regard other
items and issues as peripheral and not so important. That it has happened a surprising
amount with satellite communications links, especially remote mobile ones, is the
reason for this missive. Here's a hypothetical situation. You are a soldier. You're
deployed in a mountainous area of the Middle East, carrying an older Intelsat satellite
terminal for immediate access back to headquarters, and the headquarters has leased
a 72-MHz transponder..."
 "As the EV market grows, so does demand for
robust magnetic field sensors within these vehicles. Stray magnetic fields may diminish
the accuracy of these sensors, though, which is where active stray-field compensation
comes to the rescue." So begins Frederik Berstecher in his article entitled,
Overcome Stray Magnetic Fields with Active Stray-Field Compensation,
posted on the Electronic Design website. Continuing, "The electric-vehicle
market continues on a serious upswing: Allied Market Research forecasts show it
will reach $802.81B by 2027, up from $162.34B in 2019
[can they really estimate to 5 significant digits? -
KRB]. Such growth also pushes the need for additional magnetic field sensors
within these vehicles for position detection. The sensors are robust enough to withstand
a variety of harsh environmental conditions, temperatures, vibrations..."
 In case you haven't heard yet, SAGE Millimeter,
which was formerly
SAGE Laboratories (if I recall correctly), is as of year 2020 called
Eravant. mm-wave waveguide components are
always très-cool in appearance, and there are a bunch of them shown on the
High Frequency Electronics website. Seeing them arrayed under special lighting
in an exhibit at a trade show reminds you of a jewelry store display case. The precision
machining and often polished surfaces make them gleam. Here is a great idea (IHMO)
for the marketeers at one of these mm-wave companies: Create a children's play set
a la LEGOs consisting of plug-together waveguide components molded to look like
common parts. Many of them could be full-size if modeled after higher frequency
lines. Rigid and flexible, rectangular and round waveguide, antennas, towers, couplers
and amplifiers, circulators, rat races, and many other shapes in bright colors would
make for some awesome-looking projects and just might produce some of the world's
next RF / microwave / millimeterwave engineer. Maybe call them WEGO (WavEGuideO).
Or, create a breakfast cereal using those shapes and call them Engineerios (Cheerios). You're welcome.
 It has been a while since I saw an article
discussing stability circles for amplifier design. Ain Rehman has one posted on
the High Frequency Electronics website entitled, "Understanding Stability Circles." Even in the age of computer
design and optimization for just about everything, it always help to have a basic
understanding of what the result should look like as well as what affects the result.
He begins: "Stability circles are a tool, used to examine and analyze the stability
of an amplifier (in the case under discussion) using a graphical technique, with
the help of a Smith Chart. (Note: A free, demo version of smith chart software is
available on the web from Fritz Dellsperger). This monograph presents the stability
circle tool for engineers. It is understood that many CAD programs can generate
these, but it is always useful to understand the stability circle on an intuitive
level as a good engineering practice..."
 Pasternak has an interesting article on
the Microwave Product Digest website entitled, "CubeSats:
An Emerging Market for the Microwave Industry." In framing the story with the
history of satellite communications, the author hearkens back to 1945 when Arthur
C. Clarke ("2001: Space Odyssey") described in Wireless World magazine
a way that communications could be achieved via Earth-orbiting "Extra-Terrestrial
Relays." It begins, "Spacecraft in low, mid, and high orbits provide a diverse
array of services from TV and radio broadcast to terrestrial and maritime communications,
remote sensing, and navigation and timing. Not surprisingly, the satellite industry
has been a steady consumer of RF and microwave components for more than five decades,
and the pace is likely to increase. The driver of this good fortune is the 'smallsat'
that makes it possible for even companies and governments without enormous financial
resources to create space-based services..."
|
