This continuation of
Part I covering the basics of
diode detectors gets into some of the specific circuit configurations
and their applications. Author Robert Scott touches on regenerative and superregenerative
feedback "tickler" circuits that are able to detect very low level signals. You
have no doubt heard of 'quenching,' but how about 'squegging?' The nonlinear devices
used in the article happen to be vacuum tubes, so stay away if you suffer from
Sought by Nazi Spies
as with the poor, the spies will always be among us. This story reports on a bookstore
in New York that during World War II funneled money and technical information
back to the Nazi Party in Germany. Electronics, aerospace, and other technical publications
Radio-Craft) were chief among the sought-after sources. The
shop was a front operation that lost a huge sum of money per the official accounting
books, but had copious amounts of funds pouring in from German 'investors.' Today's
enemy money fronting operations are largely radical...
Limiter Protects 20 to
RFMW, Ltd. announces design and sales support
for Peregrine Semiconductor's new, adjustable power limiter providing protection
for up to 50 W pulsed RF input. For CW applications, the
PE45140 handles up to 10 W of power. The adjustable power
limiting threshold, from +22 to +32 dBm, enables flexibility across different
platforms and architectures. Peregrine's UltraCMOS, monolithic solution is 8X smaller
than comparable GaAs PIN diode solutions
It seems these
Sherlock Ohms adventures go through occasional slumps in the
level of profundity and profoundness. Lately, they have been very good, and this
'case' is no exception. Solving difficult problems that can have many possible causes
- compounded by being intermittent and not being intentionally reproducible - often
involves equal amount of skill and luck. Even the luck part requires the troubleshooter
being smart enough to recognize and exploit the good fortune he has encountered.
Such is the situation here where fresh-out engineering
Alastair Stell becomes a company hero.
Has New MIMO Antenna Range
Cobham Antenna Systems, Microwave Antennas, a
leading antenna producer, is proud to announce a new Multiple In Multiple Out (MIMO)
antenna range which contains almost 100 antennas. Included in the range are omni,
directional, sector, hemi-omni and blade omni antennas, all with at least two connectors.
Cobham's MIMO range makes use of polarisation diversity; vertical and horizontal
(V+H), ±45° dual-slant or even right and left hand circular polarisations
for Transatlantic Cable
knew that the British Post Office was ever in the vacuum tube development business?
This 1957 article about the world's first transatlantic telephone line (TAT-1) mentions
that the amplifier and frequency equalizer repeater circuits and components for
the Newfoundland and Nova Scotia section of line was their responsibility. Bell
Telephone Lab handled the deep-sea portion of the system that ran between Newfoundland
and Scotland. Everything was designed to have at least a 20-year service-free lifespan.
TAT-1 was inaugurated September 25, 1956, and was decommissioned in 1978 without
any technical failures, thus achieving its designed longevity...
These publications are free for the asking... and I make a few pennies on each
one to boot. Thanks.
Signals and Systems For Dummies
Wiley's Engineering for Dummies Book Bundle
Job Seeker Strategies to Stay Ahead of the Career Curve
Job Interviews For Dummies
Looking for a New Job (Or Thinking About It?) What You Should Know
A Guide to Microsoft's Cloud Productivity Suite - Office 365
astronomy has been the motivation for much research work in the design of low
noise, high sensitivity receivers, but also in determining the characteristics of
the Earth's upper atmosphere. Before sounding rockets could be launched to verify
theoretical proposals, observed versus predicted behavior in radio signals being
reflected off the moon and planets needed to be explained and, if necessary, corrected
for. One notable example of atmospheric perturbation is the rotation of polarization
caused by electrons in the ionosphere (the Faraday effect). Parametric and cryogenically
cooled receiver front end technology has been primarily driven...
It's a little difficult
to make out the shape within the
crossword puzzle grid, but it appears to be a transistor schematic
symbol. Unlike the weekly RF Cafe crossword puzzles, not all of the clues and words are
specifically related to science and engineering, but a large percentage of them
are. Admittedly, I have the advantage of a software program to help place the
words within the grid. Doing it by hand is a lot more work. I can't imagine
how the people who created the New York Times' Sunday-size puzzles were able to
do it without computer assistance!
"Live" at EMC 2014
Empower RF Systems is once again conducting live
demonstrations of broadband,
high power amplifiers with compelling performance, industry leading small size,
and user interface / functionality that dares to challenge legacy products offered
in the market. Next appearing at EMC 2014 in Raleigh (Booth #311), we will be highlighting
two different models - both covering 20 to 1000 MHz - 1 kW in a 5U chassis
and 500 W in an even smaller, 3U chassis
Electronic Warfare Receivers
and Receiving Systems, by Richard A. Poisel. Receivers systems are considered
the core of electronic warfare (EW) intercept systems. Without them, the fundamental
purpose of such systems is null and void. This book considers the major elements
that make up receiver systems and the receivers that go in them. This resource provides
system design engineers with techniques for design and development of EW receivers
for modern modulations in addition to receivers for older, common modulation formats.
Each major module in these receivers is considered in detail...
a Product Engineer
Are you looking for an exciting opportunity working for a Global Technology Leader? At
Aviat Networks, we take
great pride in hiring a workforce that is committed to supporting and strengthening
our values and attributes. If you're a results-oriented, customer centric and innovative
thinker who also takes pride in personal and professional integrity, Aviat Networks
is the ideal next step in your career. We are looking for a Product Engineer loves
to solve problems, enjoy change and know how to have fun so come and join a dynamic
team that strives to bring communications to the world
Measurement System (dB-FMS)
Here is a million dollar
idea for you to consider. I hereby dub it the "Drone-Based
Field Measurement System™" (dB-FMS™).
The concept came to me while reading a column in QST magazine discussing the use
of the EZNEC antenna radiation pattern prediction software. As you know unless a
antenna is situated in a perfect, unobstructed environment like in the middle of
a desert with a perfectly uniform ground or on a space-based platform, physical
obstacles and variations in surface conductivity can significantly alter the 3-dimensional
field distribution. Columnist Joel Hallas is a master at EZNEC and is routinely
called upon to model antenna systems for people. As important as length and orientation
of antenna elements are, the ground plane configuration can have a profound impact
on the radiation pattern...
MW&RF Living Legend
NI (formerly AWR Corporation) congratulates Dr.
Stephen Maas, who recently received the 2014 Microwaves & RF Living Legend Award.
Maas was presented the award at the 2014 International Microwaves Symposium in June
in Tampa, Florida. Maas, chief scientist of AWR Group, NI and founder of Nonlinear
Technologies, has an extensive background in low-noise and nonlinear microwave circuits
and systems. He is a prolific author and educator and has authored several books,
including Microwave Mixers, Non-Linear Microwave Circuits and Practical Microwave
Circuits. Maas has also held
for July 29, 2014
"Say again." That phrase is heard often in telephony conversations
both wired and wireless. It was coined near the end of World War II by Air
Corpsman 2nd Lt. Byron A. Susan, as reported in the January 1945 edition of
Radio Craft magazine. Lt. Susan was responsible for setting standards for
"radio phraseology" to eliminate ambiguity between aviators and
ground forces. "Say again" replaced "Repeat" because the latter is an artillery
term used to order the repeat of a gun salvo.
Publishing: Coherer to
iconumerator (electronic particle counter), the vidicon tube (TV image recorder),
the Electro Importing Co.'s Telimco (world's first home wireless outfit), the Wireless
Association of America (founded before ARRL), the Dynamophone (voice-activated switch),
the "Swatties" (members of the Society of Wireless Telegraph Engineers), the "Detectorium"
(silicon crystal detector), Ralph 124C 41+ and his sweetheart Alice 212B 423 (Gernsback
sci-fi series) were covered. Radio Amateur News
predated QST as America's premier magazine for Hams, the famous 1919 "Verboten"
cartoon (protested limitations on private radio operators from the wartime era),
the de Forest "Oscillion,"...
"Klystron" Bestowed to
Klystron is a household
word these days - literally - since every microwave oven contains one. Do you know
who registered the trade name originally? Per this advertisement from a 1945 edition
of Radio Craft magazine, Sperry Gyroscope Company did. It was actually scientists
at Stanford University (Russell and Sigurd Varian) who developed the klystron tube,
financed by Sperry as part of its blind aircraft landing system. In an act of magnanimity
that would never be considered in today's competitive markets, Sperry issued the
following statement: "From now on, the name Klystron belongs to the public, and
may be used by anyone...
Engineering Crossword Puzzle
For the sake
of avid cruciverbalists, each week I create a new
puzzle that has a theme related to engineering, mathematics, chemistry, physics,
and other technical words. You will never be asked the name of a movie star unless
he/she was involved in a technical endeavor (e.g., Hedy Lamar).
big graphic with Figures 1 through 17 reminds me of the kinds of study sheets I
used to make when cramming for exams in my college circuits courses. Did I ever
tell you about the wise guy instructor I had for my first Circuits class at the
University of Vermont? Anyway, this article provides an introductory level treatment
negative feedback in amplifier circuits. Lots of illustrations
and formulas are included. Frequencies are at baseband, so you won't learn any secrets
for high frequency amplifier stabilization, but then even RF and microwave circuits
eventually need to convert down to baseband at some point for sampling or for use
as audio or video.
July 25, 2014
I think I skipped
a week with RF an microwave magazine article updates. Those things multiply like
rabbits, so there have been a slew published since last time. Here are just a few
Method Eases Monopulse
System Jamming, D. Pan,
Overview of RF Switch
Applications, P. Bacon,
Waveguide Filters: New
Design Techniques for
Exploiting a Mature
Technology, A. Trusler
Seeing Jitter in an Eye
Diagram, J-J. DeLisle
Tee Applications (p.56), Coilcraft
Measurements in an
M. Vogel and C.J. Reddy
I ever tell you about the guy I had for my first Active Circuits class at the
University of Vermont? He was a real wise guy. During those first
few weeks our overloaded brains were bombarded with equations and Bode plots and
parameter names and circuit configurations, so the anxiety level was very high.
That was in conjunction with the same scenario in four or five other classes; you
probably know of what I write. A typical class consisted of Professor Anderson beginning
in the upper left corner of the chalk board and writing at Olympic speed as he progressed
to the extreme lower right corner 50 minutes later...
are a few more
comics from magazines of the days of yore. It is rare to find
a comic in a technical or hobby magazine these days. I don't know why that is. Enjoy.
Switch Connector by RFMW
RFMW, Ltd. announces design and sales support
for Rosenberger's 15K101-40ME4
Micro-RF test switch connector. The 15K101-40ME4 Micro-RF test
switch is an ultra-miniature (1.8 mm x 1.9 mm, height 1.5 mm) low-cost, surface
mount, coax "switch" connector for the verification of antenna/circuit performance
in any kind of small device. The connector can be used for applications that require
a low-cost, SMD, coax, point-of-entry to a PCB and/or a switch for temporarily disconnecting
nomograph. This one is for calculating the number of decibels
required to amplify or attenuate a voltage level. The chart came from a 1945 edition
of Hugo Gernsback's Radio Craft magazine, but decibels are still defined
today the way they were nearly 70 years ago. A hard copy of a nomograph residing
in a notebook or on the wall is still a handy tool when you need to do a quick calculation.
Unless you have a voice-commanded app where Siri will instantly respond with a conversion
for you, printing out one of these nomographs might be a really handy aid...
scientists suspected as recently as early 1957 that
Earth's upper atmosphere (ionosphere and beyond) temperature might
be around 1,000° K. I say 'suspected' because we had not yet launched instruments
there to make actual measurements. Soundly posited and agreed upon theory was validated
a short time later when sounding rockets reliably reported a maximum of about 1,300° K
in the upper ionosphere. We did not know for sure what electromagnetic wavelengths
and their respective energy densities would be outside the protective layers of
gases encompassing Earth. Much more was known about the depths of the planet's oceans
than of its atmosphere. Scientists knew that life was abundant...
Anatech Electronics, a manufacturer of
RF and microwave filters,
has published its July 2014 newsletter. As always, it includes both company news
and some tidbits about relevant industry events, regulations, and standards. This
month, Sam Benzacar offers his views on the subjects of power line EMF exposure,
microwave device market growth, LTE TV, GM's LTE in-automobile hot-spot, and switching
consciousness on and off. He also has a short article titled, "Curing Interference:
Never Too Late."
It's time for another
round of job hunting and career advice stories. There is no limit to the amount
of advice offered by helpful 'experts.' Many of these particular bits of guidance
for your life come from authors on LinkedIn, Monster, Money, etc., which typically
do have good content. Considering, however, the quality of helpful suggestions offered
by your friends and acquaintances in the real world, it would be wise to learn a
little about the source before potentially risking your future.
Refresh Your Retro Resume
in 6 Steps
5 Words to Avoid Saying
During a Job Interview
Top 10 Tips for Salary
ATEC for Support!
Advanced Test Equipment
Rentals provides the latest models of test and measurement equipment from top name manufacturers like
Fluke, Anritsu, R&S, Tektronix, and Yokogawa. Our primary focus is providing
a complete rental solution of test and measurement equipment to industries such
as aerospace, defense, EMC, and communications.
Restoration by Mark Blair
RF Cafe visitor Mark J.
Blair (NF6X) wrote to let me know about the
Chalco Paper Tape Reader that he procured and restored. The Chalco unit was
used in the
TPN-19 ground-based mobile airport surveillance and precision approach radar.
Mark would appreciate being
contacted by someone who actually worked with the reader on the
TPN-19. Mark has a very interesting website that you might enjoy. Says he, "I like
to collect, restore and play with military surplus equipment, and that's mostly
what this web site is all about."
for Engineers: Evaluation and Funding of Capital Projects, by Frank Crundwell.
I saw this book over on the EE Times website and figured it would be a good subject
for my Featured Book spot. With flair and an originality of approach, Crundwell
brings his considerable experience to bear on this crucial topic. Uniquely, this
book discusses the technical and financial aspects of decision-making in engineering
and demonstrates these through case studies. It's a hugely important matter as,
of course, engineering solutions and financial decisions...
of Radar - AOC Webinar
When: TODAY, July
22 from 4-5 pm EDT.
There is still
time and space available to register for this afternoon's webinar presented by
Fernando C Gonzalez. This interactive journey, from the humble
electron all the way up to the self-driving car, explores sound and light, size,
wavelength and frequency. Overview of the history and evolution of radar. From the
origins of radar prior to WWII, through pulse Doppler, CW, monopulse radars, and
to modern active electronically scanned arrays (AESA), the attendee will understand
the fundamentals of how radars work. A 10-15 minute Q&A follows.
- Women Engineers Needed
Union Radio Corporation was ahead of its time in terms of hiring
women engineers. Admittedly, they and all other manufacturers
were dealing with a shortage of male engineers due to the ongoing need by the military
for fending off the scourges of fascism, Nazism, communism, socialism, and all the
other 'isms' of the day that threatened to overtake the world. However, they should
receive due credit for going out of the way to promote the sciences as careers for
the fairer gender. The advertised positions required the successful applicant to
have earned a bona fide degree in physics, electrical engineering, chemical engineering...
"It is difficult to say what is impossible,
for the dream of yesterday is the hope of today and the reality of tomorrow." -
with a Tachometer
is a great example of how Popular Electronics and John T. Frye used
the "Carl & Jerry" series to teach some basic electronics design principles
through story telling. In this adventure, the guys decide to build a
tachometer from schematics they found in a magazine. They debate
amongst themselves how the circuits works, the best way to assemble the circuit,
component selection, vibration- tolerant mounting, and how to properly calibrate
the tach to accurately display engine revolutions per minute.
Simulation Times Up to
NI (formerly AWR Corporation) has released V11.01
of the NI AWR Design Environment™ with enhancements to
FEM EM simulation engine that cuts simulation times by as much as 70% over previous
versions. The updates in V11.01, which are specific to Analyst, include algorithm
reformulations/enhancements to both automatic mesh refinement (AMR) and fast frequency
sweeps. For high-port-count designs (10+ ports), the speed improvements seen with
Analyst are the most pronounced
for High Tech Workers
Someone had to take
the initiative to launch an improved high-tech immigrant worker program. Accordingly,
I took the liberty of creating a
K-1B Visa for high technology workers.
Congress has not officially written it into law, but American politicians and executives
make no pretense of enforcing law they disagree with anymore, so it really does
not matter. Here is how the K-1B Visa program works: It is widely known that the
United States now considers itself to be a country without a southern border. All
anyone needs to do to become an accepted American citizen (the new definition, not
the old) and enjoy all the freedoms guaranteed by our Constitution (well, except
Restoration (HP Beginnings)
Even though you would never know by today's
Hewlett Packard (HP), the company's roots are in electronics test equipment (never
thought I might have to explain that!). Most people who have been in the electronics
realm are familiar with the story of Dave Packard and Bill Hewlett starting their
business in the 12'x18' single-car garage where Dave and his wife lived at 367 Addison
Avenue in Palo Alto, California. Bill, yet a bachelor, moved into the garage in
1938 (an early entrepreneurial engineer trend setter who literally lived in his
office). Their first commercial product was the Model 200A Audio Oscillator. Hewlett
Packard went on to become the world's foremost maker of electronic test equipment
for communications, medical, basic research...
Dog on the Roof
Because I was born in 1951, I grew
up without the benefit of 1,000 cable channels available whenever I wanted them.
This was during the 1950s and 1960s when we lived in the city of Pittsburgh, PA.
Instead we had to make due with four - that is four - VHF television stations that
we could receive on a black and white TV (actually it wasn't strictly BLACK and
WHITE; there were various shades of gray). There was one TV station for each network:
CBS, ABC, and NBC, plus one 'Educational' (PBS) station. Later on, we got two independent
UHF stations. This was also the era when the 'blackout rule' was largely in effect
for sports broadcasts, and if you didn't go to the stadium for a home game...
of Their Ongoing
organization has been setup to design, develop, manufacture, test, and market complex
RF MIC and MMIC components, supercomponents,
and subsystems. Unique products for applications
in space, military, commercial, telecommunications, and consumer electronics systems.
DC to 40 GHz.
Empower RF Systems is proud to announce the approval
of a patent on "Broadband linearization module and method." New communication services
and the use of complex waveforms have created a demand for highly linearized power
amplifiers. Deviations from linearity show up as spectral distortions and/or modulation
quality degradation (EVM) in the output of these amplifiers -that is, undesired
energy, not contained in the original signal, inside or outside
Anniversary Crossword Puzzle
tranquility base here. The Eagle has landed." Where were you 45 years ago when you
heard on radio watched on a B&W TV like I did as
Apollo 11's 'Eagle' lunar module touched down on the moon - with
less than 30 seconds of fuel remaining? A
short while later Neil Armstrong and Buzz Aldrin became humans #1 and #2, respectively,
to step onto the lunar surface. "We came in peace for all mankind," was plaque
attached to the part of the lunar lander that stayed behind. Poor Michael Collins
had to be content with orbiting the moon while is shipmates went to the surface.
I created this special crossword puzzle this morning to commemorate the Apollo 11
A few new terms have
been added to the
transistor lexicon since 1958, but this list from Radio-Electronics
magazine contains more than 150 definitions that are still useful today. It is amazing
that this list was created just a decade after the transistor was invented, and
now half a century later the mot commonly used terms have not changed much. In looking
over the words, there are very few that need to be added to the original (which
Test Reports for Fuzz
Custom Interconnects announced the release of
the most detailed RF characterization conducted to-date on their flagship
Button® technology platform. The reports are geared towards 50 Ohm impedance
matching at high frequencies and include bandwidth measurements, S-parameters and
VSWR, as well as SPICE Models. The reports were released as a follow-up to the recent
IEEE IMS held in Tampa and are expected to draw a great deal of interest from the
RF design community who were eagerly awaiting their arrival
Electronics' Ongoing Support
Since 1961, MECA has served the microwave
industry specific to passive components in the DC to 20 GHz frequency range.
MECA serves all areas of the RF / Microwave
industries including world class network providers, and supporting supply chain
infrastructure. We have long been the "backbone" of high performance wired and air-interfaced
networks such as in-building, satellite, radar, and mobile communications.
Microwave Symposium (IMS) is arguably the largest single annual event for radio
and microwave engineers. According to IMS2014 event officials the show in Tampa,
Florida, boasted of a 7,500-visitor attendance. European Microwave Week (EuMW) runs
a close second place at around 7,000. In 1958, 55,000 engineers attended the Institute
of Radio Engineers (IRE - eventually became the IEEE) in New York City. IMS and
EuMW would love to have numbers like anywhere near that. Maybe the large number
of attendees was because dissemination of information was not nearly as instant
(or eventual for that matter), and the absence of the Internet or...
electronics company advertisements from the World War II
era. It represented a time when minor differences between citizens were put aside
for the good of the country (yours and mine). Nationalism had not yet been redefined
by one-worlders to mean that you hated the rest of the world, but rather that you
had pride in your country of birth - or legally adopted new country - and were willing
to sacrifice for the common good to preserve your way of life. The U.S. and Great
Britain were indisputably the leaders in technical invention amongst the Allied
powers. Germany and Japan led...
Performance MESFET Chips
BeRex, Inc. has begun shipping a new family of
chips, the BCF-series, which addresses the need for low phase noise with high gain
and power in applications such as single and multi-stage amplifiers, oscillators,
synthesizers, etc. ranging in frequency from DC to 26.5 GHz. The BeRex BCF-series
of MESFET chips are ideally suited both broad band and narrow band applications
from DC to 26.5 GHz. Typical application requires a high level of OIP3 linearity
wave radio was a boon to both professional and amateur radio operators because of
its ability to be received over longer distances using significantly lower transmitter
power. The problem was (and still is) that short wave bands typically suffer from
atmospheric ionization effects that vary depending on time of
day, local weather, solar activity, pollution, and other phenomena. Long wave's
advantage was that although it required higher power and longer antennas, it was
(and is) extremely reliable. For other than the most critical applications, idiosyncrasies
of short wave communications were accepted as the price of more convenient and lower
cost operation. Widespread adoption of short wave communications brought extensive
studies and characterization...
& D.A.S. Equipment Catalog
MECA* Electronics' new 12-page catalog features
many our extensive line of
PIM RF/microwave components with industry leading performance including RF loads,
attenuators, directional couplers, power splitters, divider/tappers, adapters, jumpers
and D.A.S. equipment.
* Microwave Electronic
Components of America
Technology magazine just published its 2014 ranking list for the
top 100 defense contractors
based on the value of contract dollars*. It should come as no surprise that Lockheed
Martin leads the pack ($10.4B) by a factor of nearly two over the runner-up Northrop
Grumman ($5.87B). My Top 10 list below has the companies listed by value of defense
contracts, whereas the original list ranked by total dollar value inclusive of both
defense and non-defense contracts. Two companies in the list, Leidos (security)
and Fluor (construction), are unfamiliar to me. The other eight design and manufacture
a mixture of electronic, mechanical, and software products for military and aerospace
customers. The CBO reports that defense spending...
Architecture and Design
Radio Frequency System
Architecture and Design, by John W. M. Rogers, Calvin Plett, and Ian Marsland.
Communication devices such as smart phones, GPS systems, and Bluetooth, are now
part of our daily lives more than ever before. As our communication equipment becomes
more sophisticated, so do the radios and other hardware required to enable that
technology. Common radio architectures are required to make this technology work
seamlessly. This resource describes practical aspects of radio frequency communications
July 15, 2014, Dilbert comic strip features the CEO of his company suggesting that
they figure out a way to insert ad images into "that little spot" that stays in
your vision for a few seconds after someone takes your picture using a camera flash.
I wonder whether creator Scott Adams realizes that he might have come up with a
patentable idea? Too late. By now the folks at Google or Apple have seen today's
strip and have their staff patent lawyers frantically generating applications as
I write this.
Subliminal advertising has been around for a long time, and it
might even be illegal in some countries, but it is not illegal...