Tuesday the 7th
Cabe Atwell has an interesting piece on the
EE Times website entitled, "Preservation
Engineers Keep Old Technology Alive." Although he doesn't mention it, the issue
of maintaining old software and hardware really was at the forefront of the Y2K
era when doomsdayers tried to convince the world that everything would stop working
at the time change between December 31, 1999, and January 1, 2000. People were scrambling
for a few year prior to see that the worst case scenario did not happen. It didn't,
thanks to them. Truth is though, a lot would have shut down if not for those doomsdayers
sounding the alarm, so they cannot be written off as nutballs.
Electro-Photonics is a global supplier of
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.
Monday the 6th
It is Labor Day in America, so a lot of
RF Cafe visitors have the day off. Being engineers, technicians, students, etc.,
even time off is often spent pursuing technical endeavors. Here are a couple good
electronics-related comics from a 1960 issue of Electronic World magazine
to help entertain you. They are from the days of in-home television repair service,
which of course is a thing of a bygone era when even family doctors were still making
house calls. The first comic might seem a bit ridiculous, but often times getting
a description of a particular type of noise a TV set is making could help diagnose
the problem. Enjoy the day wherever you are.
"A quantum bit based on a vibrating carbon
nanotube and a pair of quantum dots could be
unusually resistant to noise. Although the new nanomechanical qubit is currently
at the proposal stage, calculations by Fabio Pistolesi of the French National Centre
for Scientific Research (CNRS) at the University of Bordeaux and colleagues in the
US and Spain indicate that its so-called 'decoherence time' - a measure of how long
fragile quantum information can survive in a noisy environment - would be remarkably
long, making it an attractive platform for quantum computing. Quantum computers
can, in principle, solve certain problems much faster than classical computers because
they exploit a quantum system's ability..."
Here is a short tutorial on how to design
resistive impedance matching circuit for feeding multiple transmission lines
of equal impedance. Both series and parallel feeds are presented. As the author
mentions, ideally you would like a lossless transformer for matching, but often
a resistive network is acceptable, especially if receive signal power is not an
issue and if your transmitter power is sufficient to overcome the resistive losses
(and doesn't torch the resistors). It is also possible to match transmission lines
of different impedances, but the equation would get messy. Although it would mean
even more resistive loss, the simplest way to match unequal impedance lines is to
first match to a value most of the lines exhibit, then build a separate resistive
transformer for the line(s) that are different to connect between the main match
network and the unequal line(s)...
The Electronics Design website is
offering a free download for Lou Frenzel's "Back
to Basics: Impedance Matching" e−Book. "Impedance matching is easy if you know
the basics," he begins. "The term 'impedance matching' is rather straightforward.
It's simply defined as the process of making one impedance look like another. Frequently,
it becomes necessary to match a load impedance to the source or internal impedance
of a driving source. A wide variety of components and circuits can be used for impedance
matching. This series summarizes the most common impedance-matching techniques."
RF Cascade Workbook 2018 is the next phase in the evolution
of RF Cafe's long-running series, RF Cascade Workbook. Chances are you
have never used a spreadsheet quite like this (click here for screen capture). 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...
Aegis Power Systems is a leading supplier
of AC-DC and
DC-DC power supplies for custom and special applications. Aegis has been designing
and building highly reliable custom power supplies since 1995. They offer a complete
line of switch mode power supplies and power converters for a variety of markets
including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft,
EV, telecom, and embedded computing applications. Design and manufacture of custom
power supply solutions to meet each customer's exacting specifications. Please visit
Aegis Power Systems today.
Sunday the 5th
Theme crossword puzzle for September 5th, 2021, contains only words and
clues related to engineering, mathematics, chemistry, physics, and other technical
words. As always, this crossword contains no names of politicians, mountain ranges,
exotic foods or plants, movie stars, or anything of the sort unless it/he/she is
related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll).
The technically inclined cruciverbalists amongst us will appreciate the effort.
Friday the 3rd
"Smartphones, laptops, and lighting applications
rely on light-emitting diodes (LEDs) to shine bright. But the brighter these LED
technologies shine, the more inefficient they become, releasing more energy as heat
instead of light. Now, as reported in the journal Science, a team led by researchers
at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley has demonstrated
an approach for achieving
near 100% light-emission
efficiency at all brightness levels. Their approach focuses on stretching or
compressing a thin semiconductor film in a way that favorably changes its electronic
structure. The team identified just how the semiconductor's electronic structure
dictated interaction among the energetic particles within the material. Those particles
sometimes collide and annihilate each other, losing energy as heat instead of emitting
light in the process. Changing the material's electronic structure reduced the likelihood..."
RF Cafe website visitor Ray Gutierrez generously
provided a paper for publication a few years ago, and now has provided a follow-on
article on the subject of
intermod cancellation in RF amplifiers. Says Ray, "This paper is a continuation
work for the "New High Efficiency Intermodulation Cancellation Technique for Single
Stage Amplifiers." Published in January 2008 on RF Cafe's Paper section. The paper
describes configurations for dual and multiple parallel amplifiers and uses the
basic Reflect Forward technique for intermodulation cancellation. Some new improvements
were made to the RFAL technique to improve the efficiency and operation." Further,
"I had done much of the work for this new paper back then but got busy doing other
things in my retirement time..."
This circa 1941 QST magazine article
is provided as a reference to how these early
vacuum tube transmitters were designed and built. Modifications in the circuit
would be required to adapt this transmitter to modern standards of spectrum purity,
and the 5-meter band is no longer allocated to Amateur Radio. The 6-meter band runs
from 50 to 54 MHz, so anyone desiring to actually build a version of this radio
could easily shift the frequency a couple MHz. The weight of this rig with batteries
for running it a a mobile unit would be probably somewhere in the 10 to 20 pound
range - a far cry from today's mobile units which tip the scales at under a pound
and in a much smaller volume. This article is also a good reference for theory and
operation of some of the older equipment...
An article written by Tom Lecklider in the
October 2005 edition of Evaluation Engineering titled "The World of the
Near Field" presented formulas for three regions of the near field that relate the
largest physical dimension of the radiator to the operational wavelength. A great
chart shows the transition
area between near field and far field. There tends to be a lot of opinions (rules
of thumb) about where the transition regions exist. There was also an article in
the February 2001 edition of Conformity entitled, "Near and Far Fields
- From Statics to Radiation" that did a good job of addressing the near field vs.
far field issue. The calculator originally on this page has been removed because
of compatibility issues with outdated Microsoft OWC components...
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. 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
Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
Thursday the 2nd
This is the third installment on "Radio Aids
to Aircraft Navigation," written by Francis Gicca for Electronics World
magazine. The first two appeared in the July (LF Ranges and Direction Finding) and
August (VHF Omnidirectional Range - VOR) issues. "Terminal
Instrument Navigation (ILS & GCA)" covered here in the September issue,
are by far the most technical and complicated systems. The Instrument Landing System
(ILS) is a "blind landing" system where the pilot navigates the aircraft (airplane
or helicopter) along a set of very narrow RF beams configured to provide glide slope
and azimuth courses. Ground Controlled Approach (GCA) involves human guidance via
radio communications using ground-based radar equipment. I worked on both Airport
Surveillance Radar (ASR) and Precision Approach Radar (PAR) very similar to those
shown in the accompanying photos...
Electronics (LG) successfully demonstrated the transmission and reception of wireless
terahertz (THz) data over 100 meters in an outdoor setting. This milestone was
achieved in collaboration with Fraunhofer-Gesellschaft, Europe's largest applied
research lab, on August 13 with the data traveling between Fraunhofer Heinrich Hertz
Institute (HHI) and the Berlin Institute of Technology in Germany. As 6G THz has
short range and experiences power loss during transmission and reception between
antennas, one of the biggest challenges in the evolution of wireless 6G has been
the need of power amplification to generate a stable signal across ultra-wideband
frequencies. The power amplifier developed by LG, Fraunhofer HHI and Fraunhofer
Institute for Applied Solid State Physics (IAF) was crucial to the success of this
the circle" may as yet be an unattainable goal for even the best mathematicians,
but the November 2012 edition of The Family Handyman magazine had a tip
for how to use a square (of the framing type) and two nails to draw a circle. The
author comments, "Don't ask us why this process works; all we know is that it does."
Out of curiosity, I dug out my father's old Audels Carpenters and Builders Guide
(printed in 1945) to see if it described the method and if it did, was there an
explanation offered. It did, and he did. Read on...
Electrical wiring drawings or blueprints
are maps which show you' the location and circuit connections of every piece of
electrical equipment aboard ship. Blueprints properly used are an invaluable aid
"trouble shooting", in other words, in isolating faults in an electrical circuit.
This is undoubtedly the most important work of the naval electrician. You should
therefore study the training course Use of Blueprints (NAVPERS 10621) to get a basic
understanding of how blueprints are made and used. Then read tills chapter and you
will know all the information that goes into Navy wiring blueprints and how to use
Axiom Test Equipment, an electronic test
equipment rental and sales company has published a new blog post that informs people
about the versatility of an
electronic load. When an AC or DC supply must be evaluated, during design or
even for maintenance, an electronic load provides much needed capabilities. Electronic
loads provide insights into how the power source behaves under different load conditions
for AC or DC power sources. By keeping an electrical parameter such as voltage,
current, power, or resistance fixed, it can measure voltage/current or power/resistance
under constant-voltage (CV), constant-current (CC), constant-power (CP), and constant-resistance
(CR) conditions. Starting the search for an electronic load usually begins by understanding
an application's requirements, for AC or DC testing...
FCC has published an
interactive map showing 4G LTE coverage in the U.S. The thumbnail here has all
the providers turned on, and you can see in the full-size map that while there is
a lot of overlapping coverage in densely populated areas, there are still places
in the western mountains and deserts where there is no coverage at all from any
provider. It will zoom down to house level for determining coverage. The amount
of hardware (towers, cables, antennas, BTS's, etc.) involved is huge, as is the
amount of electricity and distribution lines required to power it all. I do not
recall seeing a number anywhere estimating the global carbon footprint of the cellular
systems - including towers, data centers, mobile devices, batteries, AC power delivery
and usage, raw mineral resources, manufacturing, packaging, transportation to end
users, landfill impact...
Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
Wednesday the 1st
Hugo Gernsback, in a 1938 issue of his
Radio-Craft magazine, lampooned his contemporaries who boldly declared
that by then (1938) there was
nothing left to be invented regarding radio equipment for shortwave communications.
Wisely citing the well-known instance of a patent examiner who quit his post in
1870 because, as the man put it, all useful things had been invented and there was
nothing meaningful left to patent, Mr. Gernsback challenged his readers to keep
this article for 25 years and then go back and read it while being aware of all
the new and wonderful short wave devices that had been invented since 1938. It has
now been more than 80 hence since the challenge was issued, and not only has the
state of the art of short waves advanced beyond any of their wildest dreams, but
entire new realms of radio and optical communications have been born and evolved
that only futurist like Hugo Gernsback, H.G. Wells, Jules Verne, and Edgar Allen
Poe (Poe was considered a great sci-fi writer) could ever have even imagined.
is an amazing material. It can be strong, flexible or lightweight - and sometimes
all of the above depending upon the tree. Wood can be used on its own, or it can
be processed to create materials with an even wider range of desirable properties.
So, it should come as no surprise that scientists in Japan are looking at how
wood could be used in space. Previous studies have shown that wood can withstand
the extremes of temperature experienced in space - it holds up well from in the
-150 to 150C range - and it is not affected significantly by near-vacuum conditions.
Now, Koji Murata at Kyoto University's Biomaterials Design Lab and colleagues are
sending several samples of wood to the International Space Station (ISS)...
When this January 1948 issue of Radio
News magazine was published, a mere two and a half years had passed since the
end of World War II, and military planners were already strategizing about
what a future war might look like. Two technologies that had a huge effect on the
previous efforts were the atom bomb and the guided missile; therefore, they were
prominent in discussions. Germany's use of the V−1 Buzz Bomb is a familiar example
guided missile that struck terror in the hearts of populations that experienced
its devastating destructive power. Ditto for the V−2 rocket. The U.S. developed
a few missiles of its own, particularly immediately after WWII when it had the assistance
of Werner von Braun and other notable rocket scientists who worked for the
U.S. space effort after the war...
Artech House today announced the publication
Circularly Polarized Dielectric Resonator Antennas, by Raghvendra Kumar Chaudhary,
Rajkishor Kumar, and Rakesh Chowdhury. This unique resource introduces wideband
circular polarization radiation in dielectric resonator antennas (DRA). It presents
five key feeding techniques, including coaxial probe, microstrip, conformal strip,
aperture, and coplanar waveguide. It also covers different shapes of dielectric
resonator antennas, which will lead to improvement of circularly polarized (CP)
performance and explores the advantages and disadvantages of each feeding technique.
Important characteristics of DRA, including high radiation efficiency, high gain,
wide range of bandwidth, low ohmic losses, high power handling capability, and 3D‐design
flexibility, are discussed. New techniques that generate broadside circular polarization
(CP) by using sectored DRAs...
In his latest The Accidental Engineer
blog post, Reactel's Jim Assurian offers his extensive expertise on the topic
of Filter Topologies. He begins
thusly: "Have you ever asked yourself, “why did Jim quote me a cavity filter when
I was sure a discrete component filter was what I wanted”? In this post, I'll detail
several different filter topologies and reasons for using them. In advance, however,
please understand that this is a general discussion – each situation is unique,
and a given set of requirements may cause a deviation from the guidelines to follow..."
The Accidental Engineer has many
other blog topics that will interest you including Filter Mounting Options, How
Wide Can You Go? (in bandwidth), and Connectors & Power.
New Scheme rotates
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LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
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The management team has additional experience in optical power testing, military
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languages often used in programmatic systems. Extensive experience in a broad spectrum
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