Every Sunday I create a
crossword puzzle using a
word list that I personally created and added to during over a decade of making puzzles. All of the words are related to
engineering, science, mathematics, chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing designers.
Cahak, owner of Sunshine Design Services, has submitted another paper on noise titled, "Noise and Noise Measurements."
This is a very extensive treatise on noise definitions and their associated formulas as applicable to laboratory and report
writing purposes. Derivations have been avoided in order to keep the focus on practical applications. Material is pulled
from many established industry authorities on noise. I like the final sentence in the conclusion, "Clearly noise has much
to teach us about many things and is of great use, in addition to being the bane of communications."
This has been a good month for articles. Here are a few more you might find useful.
- An Important Secret About
by Eric Bogatin
Logging of RF Power
by Orwill Hawkins
Measurement Sensors: For
by Chris Grachanen
Leveraging the Use of a
Radio Frequency Planning
Design Tool for Modern
by Malcolm Edwards
Leveraging next generation hardware and software innovations that are part of Empower’s “size matters” architecture,
several unique configurations of these HPAs are being shipped to key customers. This particular set of high power HPAs build
on the size, weight and power advantages already demonstrated with commercial product releases in the broad market, “size
matters” product family. This recent and unique Airborne Pulse HPA
solution features UHF and L-Band pulse amplifiers tied to a shared
"We are passionate about
that work better, and we have been delivering on that passion for 25+ years, helping dozens of companies bring
innovative wireless products
to market in a variety of markets. We design and develop products that analyze, measure,
control, and communicate. Our in-house
developed customizable, modular wireless platform, RFOS™ , allows us to do this better, faster and with less NRE cost. We wrap our core embedded wireless
capability in full service 'spec to production' product development."
The American Radio Relay League (ARRL) has
been on the cutting edge of communications technology since its founding in 1914 by Hiram Percy Maxim. Then, as
now, many of the nation's top electronics and antennas
experts have been intimately involved in the design, testing, operating, and regulating aspects of radio systems. Over time
radar, software, and computer technologies have been added to the mix of specialties as have program management, field deployment
and fixed station logistics, facilities management, and many other talents. A natural result of all the human capability
affiliated with the ARRL is the collective personal investment in keeping flagship...
periodically sends me e-mails that highlight recent key court cases that can significantly affect the effectiveness of expert
testimony, both for the plaintiff and for the defendant. This article by Bob Ambrogi reports on a 7th U.S. Circuit Court
of Appeals judge spanking legal entities for not exercising due diligence when vetting matters of science and simply accepting
the testimony of 'experts' because of a
ignorance of science. "This lapse is worth noting because it is indicative of a widespread, and increasingly troublesome,
discomfort among lawyers and judges confronted by a scientific or other technological issue," Circuit Judge Richard A. Posner
wrote." We are used to hearing people - professionals included - dismiss their lack...
I do a fair amount of perusing tech articles
on the Internet and found a few recently that might be of interest to you.
Lab Equipment: To Build
Or Not to Build
Six Tips for Better
Wanted: Brightest and Best
Young Engineers for
Active Antenna Systems
Skyworks Solutions, an innovator of high performance
analog semiconductor enabling a broad range of end markets, today announced that its wholly-owned subsidiary Isolink is
customized optical solutions to Varian Medical for radiation oncology applications. Varian is the
world’s leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy,
radiosurgery, proton therapy and brachytherapy
Kete Microwave Electronics Co., Ltd. specializes in designing
and manufacturing state of the art RF/Microwave passive components
solutions including isolator/circulator, RF resistors, terminations,
attenuators, multilayer chip ceramic capacitors, feed-through capacitors, directional couplers, power divider/combiners,
3 dB hybrid couplers, etc. Connectorized, surface
mount, drop-in, and waveguide versions available.
Cruciverbalists rejoice! Here is
another crossword puzzle to try your technical prowess. Unlike the weekly RF Cafe crossword puzzle that contains only engineering,
science, mathematics and other tech words, this one from Electronics World does have a few unrelated words. The big difference
between making crosswords then and now is Mrs. Le Fevre had to construct the grid of words manually, whereas I
just create a huge file of words and definitions, draw the grid outline, and then click a button to have software put it
all together. I'm guessing it took a couple hours to make this puzzle; mine take about 15 minutes.
RF Cafe is back in business full-time! After a busy, tiring
few days, Melanie and I have completed our relocation from Erie, Pennsylvania, to Alpena, Michigan. Why did we leave Erie
and why did we move to Alpena? The answer is multi-faceted. Although we really like Erie, the state of society has really
degraded there since we moved there six years ago. Property and school taxes, while already very high to begin with, have
increased significantly over that time. A news article from Erie this morning, read online, reported that school taxes will
increase yet again...
I know what you're thinking... but remember,
this was 1958. I've been waiting for months to post a couple Christmas-themed
Carl & Jerry articles from old editions of Popular Electronics. Carl & Jerry, if you
are not familiar with them, are a couple electronics-savvy teenagers who, in the style of the Hardy Boys, manage to get
involved in a series of criminal investigations. With headquarters based in their parent's basement, the two friends cobble
up strategies and contraptions for snaring the bad guys. They have quite an impressive collection of test equipment and
radio gear at their disposal per the drawings. In this episode we are introduced to the word "osculation." If you already
know, don't tell us.
"The facts and knowledge learned in
any course will become obsolete well before you retire. The ability to think critically is a skill that will last a lifetime."
Kenneth C. Young, University of Arizona, in December 2013 Scientific American
Dow-Key Microwave is the world's largest manufacturer of
electro-mechanical RF switches. We are AS9100/ISO-9001 certified and
committed to providing unparalleled customer service,
competitive pricing, on-time delivery and products that are distinguished by quality and reliability. Dow-Key offers the
largest switch product line in the world with over 10,000 unique configurations.
Please excuse any delay in response for the next couple days - maybe through Tuesday. Melanie and I are moving to our
new (well, new to us) home in Michigan and will be on the road for a bit. Thank you for your
Every Sunday I create a
crossword puzzle using
a word list that I personally created and added to during over a decade of making puzzles. All of the words are related
to engineering, science, mathematics, chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing
Computer modeling of antenna radiation patterns
has evolved from a relatively simple electric field equation that diminishes as the inverse of the distance from the source,
to exotic, highly sophisticated numerical methods that account for conducting and dielectric surfaces and volumes. A spreadsheet
can be built rather quickly to calculate and graph the free-space azimuth and elevation
for a 1/4-wave whip or a dipole antenna using textbook formulas, but building a model for displaying the 3D radiation
patterns of a cellphone placed next to a human head, or a UHF radio antenna on top of an aircraft takes some pretty serious
computing power. In large part we owe a debt of gratitude to the Ph.D. types who have labored hard to make such tools...
has released new designs for a 902 to 928 MHz cavity bandpass filter,
a 1850 to 1910 MHz/1930 to 1990 MHz cavity duplexer, a 840 to 960 MHz circulator , and a 5 to 18 GHz 8-way power divider.
All can be ordered directly through their AMCrf web store.
Microwave is a leader in technically differentiated electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control critical systems
for the global microwave electronics market place including commercial and military wireless
telecommunications. Dedicated to R&D of standard and custom design quality Ferrite Circulators and Isolators from 380 MHz
to 23.6 GHz.
Here is a quick, 10-question
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.
Here are this week's suggestions, plus a couple others I found as well.
- 6 Memorable Engineering
7 Missed Opportunities
That Can Cost You That
Can You Make a
U-Turn? (leave, then go back)
How's the Engineering Job
Market? Depends on Whom
- U. of Maryland School of
Engineering job Search Tips
Windfreak Tech designs,
manufactures, tests and sells high value radio frequency products such as RF Signal Generators & Synthesizers, RF Power
Detectors, RF Mixers, RF Upconverters and RF downconverters. We develop high quality, reliable, low cost products to
make your life easier. Windfreak Tech is developing high quality, low cost products to make
life easier for RF Engineers and hobbyist. Future products will be more synthesizers, transmitters, receivers and test equipment.
All at low cost.
Forrester Research Report: The
Future of Mobile Application Development. This report, which is the vision report of the mobile app development playbook
for Application Development and Delivery professionals, focuses on the changes application developers need to understand
if they want to build modern applications that deliver contextual customer experiences. With more than 1 billion smartphones
worldwide, and tablets numbering in the hundreds of millions, the scope of the mobile revolution rivals that of the move
from monolithic systems to client/server computing in the 1990s...
Baluns are not devices familiar to most engineers even if they have
been in the RF business for many years. Most have heard of them but few probably really know what a
balun is, how it works, and how it is used.
Admittedly, it wasn't until maybe a decade
ago that I ever even came into contact with one - at least that I was aware of. Having spent most of my career connecting
cables and waveguide to pre-designed, pre-packaged components, there was never a need to convert between balanced and unbalanced
transmission lines. The many analog circuits that I did always used ICs that had single- or double-ended inputs and/or outputs
so it was never necessary to be concerned with the details. Now that I have been reading the ARRL's QST magazine monthly
for the last few years, an appreciation for...
Servomechanisms are all around us in
the form of electronically actuated controls for our cars, stepper motors in our ink jet printers, overhead garage door
openers, and anywhere else you can identify where a combination of electricity and mechanics operates with some form of
positional sensing and feedback. The author of this article in one instance declares a control circuit with a human operator
as part of the operation as being "open loop," but I contend that the human element is part of the loop and therefore constitutes
a component in the effectively "closed" loop, albeit not strictly a pure electromechanical system. Those of us who operate
radio-controlled model airplanes, boats, cars, etc., are very familiar with servos for moving control surfaces as commanded
by the transmitter's joystick position.
Yes, this is another article that will probably appeal to a small
percentage of RF Cafe visitors, but please countenance my indulgence in things aeronautical as well as things electrical.
The early 1930s was a time when both
airplanes and electronics
were a wonder and a mystery to most of the public worldwide. Of course today both are still a mystery to the public but
the wonder is gone - it's merely taken for granted. Many idiosyncrasies of airborne electronic communications were encountered
for the first time, like the need for proper grounding and static electricity dissipation. Ruggedization of chassis assemblies
in terms of mechanical vibration and shock as well as for temperature extremes...
Your New Job Title Is "Accomplice," by Scott Adams. If you are looking for a gift for your engineer
spouse, friend, son, or daughter, then what could be better than the latest collection of Dilbert comics?
Both traditional paperback and newfangled Kindle versions are available. Not the reading
type? How about a
Dilbert 2014 Calendar? Seriously, if you are buying the calendar because your engineer is not a
he/she would be better served with
Learn to Read, by Zac the Rat (the name doesn't really rhyme, BTW).
Does anyone still manufacture new
vacuum tubes? The simple answer is yes if you are referring
to the kind used in household radio and television sets, but don't expect to find a full line of replacements. Also, don't
expect them to be made anywhere other than places like China and Russia. China does it because mainly to service the rest
of the world's demand for restoring and maintaining vintage equipment. Russia probably does it to supply its own military
and civilian populace which largely still hasn't heard of transistorized electronics (just joking,
kinda). Three of the most widely available newly produced vacuum tubes are made by JJ Electronics, Valve Art, and
Ruby Tubes. They are all over Amazon.com and eBay at reasonable prices. If you are in the market for vacuum tubes and prefer
in 1979, Reactel is an industry leader in the design and manufacture of
RF and Microwave filters, diplexers, and sub-assemblies. We offer a line of filters covering DC-50 GHz. The
latest in CAD/CAM methods and equipment in all of our design and manufacturing processes are used. We feature a modern,
well-equipped machine shop complete with multiple CNCs, which gives us the ability to produce long production runs quickly
and economically. Our testing department is equipped with the latest in Agilent Technologies Network Analyzers offering
quick, dependable, and accurate measurements.
This is one of the best job descriptions
I have ever seen. It reads like it was written by real engineers who need a really good person to work with the team. To
EE UAV Avionics Design and Certification
"Unmanned Aerial Vehicles (UAVs)
in civil airspace are the next big thing. Sagetech is a leader in UAV avionics and has exciting projects starting now in
FAA / military UAV design and certification. We are building a kick-ass team. You might fit if this grabs
you: We seek highly talented, disciplined, imaginative engineers (RF design, embedded,
or FPGA programmers) who love creating novel and highly efficient solutions in a requirements-based design environment. That’s
not easy. We seek team members who are like us, who are energized by challenge."
in 1956 currency is equivalent to about $43,000 in 2013, per the U.S. Bureau of Labor Statistics' "Inflation Calculator."
That is the value of the amateur radio equipment used by Mrs. Mary Burke in her work handling "an average of 3000 messages
per month, principally for service personnel overseas." For her tireless efforts, she was the first woman to win the coveted
Award Cup (sponsored by General Electric). Most of Mrs. Burke's communications was via
Morse code, where she restrained herself to "about 30 words a minute to maintain accuracy". Way to go, Mary!
Remember the old adage about not throwing away that wide tie
because someday it will be back in style? Well, the good folks at Neverware have built a business model and product that
exploits that concept. "Neverware installs powerful software on schools' existing computers, taking over the 'heavy lifting'
and allowing the computers to run like new. Neverware's servers can supercharge any PC - even if it's ten years old and
missing its hard drive." Those of us who have been using computers since the 1970s ['78 for me]
know this system as a network with dumb terminals. The main difference between then and now is wireless connectivity rather
than copper cables. Calling the server a "Juicebox" helps the sales pitch
and with cinching the deal - it sounds trendy. I have long predicted that the "personal" computer in business and other
large networks like in schools and government offices would eventually come full circle...
"Twitter is the only place where you're thrilled when a complete stranger starts following
you." - Anon
PMI Model No. SWN-2181-TRA is a
pin diode transfer switch that operates
over a frequency range of 0.5 to 18.0 GHz. It has 60 dB min of isolation, max insertion loss of 3.5 dB
and a max input power of +10 dBm CW. This model incorporates a TTL compatible driver for easy system integration
and is supplied with removable 2.92 mm (F) connectors in a housing that measures 1.0" x 1.0" x 0.25"
This design for a
"Swiss Quad" antenna appeared
in the September 1967 edition of QST magazine. One of its touted strong points is not needing spreaders or a boom. I am
not an antenna design guy, so I can't comment on its usefulness. No gain measurement was provided by the author. The article
states that the antenna had not yet enjoyed widespread adaptation in the U.S. at the time of the writing. A Google search
for Swiss Quad antennas turns up a handful of modern examples. I could not locate an example of a computer-generated gain
plot (radiation pattern) for the Swiss Quad, so if you know where one exists, please let me know so I can post a hyperlink.
Maybe you own a copy of EZNEC and can model it?
This is a BIG
crossword puzzle so be prepared to spend
some time on it. In fact, if you find yourself being dragged along for a major Christmas shopping jaunt, then you might
print it out and take it with you to be entertained whilst sitting on the mall bench. As always, this puzzle contains only
science, engineer, and mathematics type words - no numbnut movie star names or obscure mountain peak names.