really good researchers set out to write books on history, they
do not simply cull information from the publications of fellow contemporary
authors; instead, they look for sources that were published during
or around the time of the subject being covered. Doing so helps
minimize the possibility that inaccuracies have crept into the knowledge
pool and that information other authors might have either deemed
insignificant or have missed can be recovered. With a bit of luck,
sources are discovered that have never been used before. That is
part of my motivation for going to the trouble of buying these vintage
magazines and posting articles like this one which reports on early
maser developments. It delves fairly deeply into the solid state
physics of rare earth minerals that
early masers and lasers relied upon to function, including energy
a Tech Business: A Practical Guide for Anyone Creating or Designing
Applications or Software, by Alex Cowan. Why not make 2014 the
year you finally launch the business you have been thinking about
and/or working on seemingly forever? "Starting a Tech Business offers
practical checklists and frameworks that business owners, entrepreneurs,
and professionals can apply to any tech-based business idea, whether
you're developing software and products or beginning a technology-enabled
business. You'll learn: 1. How to apply today's leading management
frameworks to a tech business 2. How to package your product
idea in a way that's highly actionable for your technical team 3. How
hard to believe but it's the last day of 2013. These are some of
the final good tech articles of the year. 2014 holds lots of promise
for our industry and there are already many good articles sitting
queue for publication. You'll see them announced here. If I miss
something, please let me know.
In Defense of DARPA;
Lamenting Bell Labs,
Tapping into a New RF
Energy Source Found in
Digital Processing Circuits,
Detecting ESD Events
Active Antenna Systems
Enjoy Growth, Iliza Sokol
RF Technology in Semi
Science magazine ran a short feature titled "Outer Space, Indoors,"
in the January 2013 edition. The main photo is a shot of the inside
RF anechoic chamber at the Technical University of Denmark
(DTU). Its thousands of RF absorbing
pyramids are painted a dark, electric blue with black tips, which
makes for a very stunningly artistic image. Narcotics-inspired sculptors
of sculptures could scarcely improve on the visual impact of this
imminently and supremely functional structure. Interestingly, I
could not find a single picture of the anechoic chamber on the DTU
website other than a small section of it from before the new paint
job. According to my search for the original, the one in PopSci
appears to have originated on the website of photographer Alastair
Philip Wiper, where many high resolution views of the anechoic chamber's
inside are posted. A steel Faraday cage encloses the chamber, but
I could not find any photos of it. A picture of the power, data,
and RF cabling interface(s) would have
been interesting to see.
Microwave is a valued supplier of high quality
microwave passive components in the frequency
of DC to 85 GHz. Because of our large library of designs, we
are able to provide custom products with little effort and in most
cases with no additional price increase above the standard catalog
item. New products are introduced on an almost monthly basis, the
most recent of which are high power directional couplers and power
knowledge is an enabling power to do either good or bad - but it
does not carry instructions on how to use it." Theoretical physicist
Richard Feynman in The Value of Science
is the final
engineering crossword puzzle for 2013. The year sure has flown
by, as they all do anymore. As always, all the words are engineering,
science, mathematics, chemistry, astronomy, etc., related. 2014's
first crossword is a monster, so be prepared for a challenge in
Solutions introduces a highly integrated
5 GHz WLAN front-end module for reference designs targeting
smartphones and tablets in a 2.5 x 2.5 mm, QFN package. The
SKY85702-11 incorporates a power amplifier and a SPDT transmit and
receive switch for mobile/portable 802.11ac applications and systems.
Operates from a single supply voltage of 3.6 V, with an enable/disable
function that allows power savings during off mode. Integrated
power detector with 20 dB of dynamic range provides closed-loop
power control within the system.
is a rather unique type of
crossword puzzle that uses numbers rather than words. It appeared
in the April 1959 edition of Popular Electronics. The software
that I use to create the RF Cafe crossword puzzles each week has
the ability to create such a puzzle, but I have never made one because
it would take a lot of time to build a clue / answer file to be
drawn upon for input. Maybe some day I'll do it, though.
Electronics ran a 5-part series on test equipment usage. This installment
is on the use of a vacuum tube voltmeter (VTVM)
for making DC measurements. Don't pass over the article just because
it refers to a vacuum tube tester since there are lessons that apply
to even the most modern transistorized, computerized meter. Author
Larry Klein discusses mainly the DC functions, providing both functional
descriptions of the circuits and how to use them for making accurate
measurements. FET-input digital multimeters
(DMMs) have largely replaced VTVMs,
but they can still be found in some older electronics development
labs and hobby benches.
Technologies designs and manufactures solid state broadband linear
RF power amplifiers
for commercial, military, medical and industrial applications. RF
amplifiers range 10 kHz to 3 GHz in frequency and power
levels exceeding 1 kW.
Standard products can be quickly
modified to your specific requirements. Full custom requests are
welcome. Our team of RF Engineers have over 20 years in the field
and are dedicated to providing the best in value, performance and
is another item that appeared in the December edition of a local
publication by The Good
"Introductory Chemistry was taught at Duke University for many
years by professor Bonk. One year, two guys took the class and did
pretty well on all the quizzes and mid-terms - so much so that going
into the final, they each had a solid A. These two friends were
so confident going into the final that the weekend before finals
week, despite the Chemistry final being on Monday, they decided
to go to the University of Virginia to party with some friends.
They did this and had a great time. However, with their hangovers
and tiredness, they overslept all day Sunday and didn't make it
am not of the Occupy Wall Street (OWS)
mindset, but an honest assessment of the
between the Haves and Have-nots has indisputably increased considerably
in the last decade or so. A recent report by the good folks at EE Times
culled data from sources like Roosevelt Institute, IC Insights,
and the AFL-CIO to present the rather shocking reality of modern
day global caste systems (my characterization)
firmly in place. In summary, average pay for 2012 including salaries,
bonuses, perks, stock awards, stock options and other incentives
for CEOs of the U.S.'s 327 biggest companies was $12.3 million.
By comparison, the 2012 average yearly pay for the private sector
was $44,300 per the Social Security Administration, and for government
employees it is $78,500 (77% higher than private
sector). It leaves me conflicted where on the one hand...
Corporation, the innovation leader in high-frequency EDA software,
announces the winners of its
2013 Xidian University student design competition, held this
autumn in Xi’an, China as part of the company’s global
Student Design Competition Program. The Xidian competition was
announced in June of this year and resulted in dozens of high quality
designs being submitted. The winners were announced during an awards
ceremony this November.
list of items will help you to
resumes submitted by applicants to your company. If you are
thinking about including any such phrases on your own resume, be
aware that we're all on to you now.
‡ My background
and skills match your requirements: You're probably looking for
someone more experienced.
‡ I am adaptable:
jobs a lot.
‡ I am on the go:
I'm never at my desk.
‡ I'm highly motivated to
The minute I find a better job, I'm
‡ I have formal training:
I'm a college drop-out.
‡ I interact well with co-workers:
I've been accused of...
Matrix designs and manufactures RF and microwave
measurement (T&M) instruments and components and is a subsidiary
of National Instruments. We proudly
within our facility a wide variety of proprietary microwave hybrid
components for use in instruments, including state-of-the-art samplers,
mixers, high-performance YIG-tuned filters, and multipliers.
Communications, located in suburban Westchester County, NY, is a
leading provider of temporary large scale RF and fiber optic systems
to the TV and special event industries. We are currently seeking
an experienced and very motivated individual to be a
supervisor and leader in our two-way radio communications department.
The qualified candidate will have a minimum of five years hands
on experience, and three years at a supervisory level, building
and deploying two-way LMR equipment, infrastructure and systems
including multi-channel, multi-site installations with transmitter
combining. RF over fiber, voting, radio over IP and wired/wireless
backhaul skills are a significant plus. Additionally...
spite of the proliferation of cellphones and near ubiquitous communications,
there are still many applications that require private 2-way communications
systems. Emergency services like police, fire, and ambulance; amateur
radio, vehicular dispatch for utilities, delivery and repair services;
and anywhere that cellular service is not either available or extremely
reliable, cannot rely on cellphones for mission critical needs.
There are a lot of legacy
2-way radio system antennas and associated towers still being
used and many new installations in place. This article in Radio &
TV News gives a good overview of the issues of concern with 2-way
radio antennas and towers.
DTA-1G18G-60-CD-2 is a non-reflective, 10-bit programmable,
60 dB pin diode attenuator with step resolution as low as 0.06 dB
that operates over the frequency range of 1.0 to 18.0 GHz. This
model is compact in size measuring only 2.0" x 1.81" x 0.88".
Girls of Atomic City: The Untold Story of the Women Who Helped Win
World War II, by Denise Kiernan. Sometimes when deciding
which book to use for this feature I look at what other RF Cafe
visitors have purchased other than ones I recommend. Most items
are electronics related, either books or devices, but occasionally
titles like this appear and are relevant enough to use for the
Book (lots of great photos). "At the
height of WWII, Oak Ridge, TN, was home to 75,000 residents, consuming
more electricity than New York City. But to most of the world, the
town did not exist. Thousands of civilians - many of them young
women from small towns across the South - were recruited to this
secret city, enticed by solid wages and the promise of war-ending
are a few of the latest circuit design and theory articles from
electrical engineering websites.
Phase Noise and the
Y-Factor Noise Figure
Use a Heated Diode as
a Flow Sensor
H-Bridge: Black Box Or
Are Details Important?
Marketing for Engineers
The Future of Interposers
for Semiconductor IC
EMC Questions Answered
Do You Know Your
Thanks once again for helping to make RF Cafe a success. I truly
appreciate the support of advertisers and visitors. Your inputs
are always welcome.
are a few of my favorite
Christmas music videos. They include an eclectic mix of
(new for 2013), the Trans-Siberian
Orchestra, an unlikely duet sung by Bing Crosby and
Bowie, and Casting Crowns. Watching the instruments being played
really enhances the effect of the song.
Solutions has introduced a 0.7-1.2 gigahertz, single-die cascode,
GaAs, pHEMT LNA for cellular infrastructure applications such
as tower-mounted amplifiers, remote radio units, repeaters, and
base stations. The new LNA offers very low noise figure and high
linearity along with excellent return loss and gain flatness in
a small 2x2 mm, no lead plastic package. On-die active bias
design of the SKY67111-396LF ensures consistent performance and
enables unconditional stability with a 5V supply...
Law: "It always takes longer than you expect, even when you take
into account Hofstadter's Law." -
Douglas Hofstadter (hat tip to Gary
customers have been a problem since time immemorial. Said dirt bags
ask you to perform a service and/or provide a product and then either
try to cheat you out of full payment or refuse to pay at all. Back
in the days when repairmen made in-home visits for radio and television
sets, evidently the problem could be really bad. Art Margoli wrote
this article for Radio & TV News describing methods
he devised to handle, and most importantly avoid, uncomfortable
situations and stave off ugly confrontations with customers. One
such scheme was to have customers sign a "cognovit
note," which is an extraordinary document by which a debtor
authorizes his or her creditor's attorney to enter a confession
in court that allows judgment against the debtor. Of course litigation
would probably cost more than the bill was worth and therefore would
not likely be pursued...
you have ever dreamed of having your own
watch, too bad, you'll have to wait a little longer. It's not
that none exist, it's that only 12 will be made at this time
(pun intended), and I'm guessing they're
all spoken for - you probably couldn't afford one, anyway. How much
for this masterpiece of horological precision? Maker Hoptroff Ltd.
isn't saying. "Big deal," you might say, "I have clocks synched
to the WWVB signal from NIST's laboratory in Boulder, Colorado."
This watch does NOT use that signal; the No. 10 watch
has its own onboard ovenized cesium atomic standard. The watch face
is so covered with dials and pointers (28)
that you have to look for the actual clock part - akin to modern
cellphone that has so many...
Have a Merry
(only tech words & clues)
Solutions, Inc. introduces a 2110-2170 MHz
single junction, robust lead isolator in an industry leading,
small footprint, 11 x 11 mm surface mount package. The
SKYFR-000727 is ideally suited for various wireless/cellular
infrastructure applications including small-cell designs where space
constraints exist. Designed for automated SMT placement, the isolator’s
insertion loss is less than 0.30 dB over an operating temperature
range of –40 °C to +100 °C.
a vertically integrated company that designs and produces its RF
products in house all the way from raw material to the end product,
introduces a line of
multi-directional coaxial connectors and adapters. Multi-directional
adapters are used to facilitate coaxial cable routing. Jyebao's
patented multi-directional adaptors permit smooth rotational movement
around two axis allowing the adaptors to move in virtually any direction.
SMA plug to SMA jack, SMA jack to SMA jack, and SMA plug to SMA
plug multi-directional adapters offer low loss and low VSWR at all
saved this poem from the December 1935 edition of the ARRL's
QST magazine for now since it might be the last day of work
for the year for many people. "The
Day Before Christmas" was penned by radio amateur Robert H.
Votaw after the manner of the classic "The Night Before Christmas."
It is rare to see such a poem printed in a technical magazine these
days, but it was fairly common back in the day. To wit: "Ravin"
Supply" (1944), "Pre-Radio"
Radioman's Nightmare" (1945).
Microwave, a technology leader in RF filtering, relies on
AWR's Microwave Office® circuit design software for its cavity
filter tuning and optimization, as well as the design
active RF electronics and planar components on PCBs, including LNAs,
drivers, PAs, dividers, hybrids, attenuators, oscillators, and planar/discrete
filters. “Microwave Office is intuitive to use. Its high quality
simulation models enable us to achieve fast, accurate and optimized
designs. AWR tools help us to achieve 'Smaller, Lighter and Smarter'...
Electronics is a provider of
RF & microwave
test equipment including peak and average power meters, modulation &
audio analyzers, RF millivolt & capacitance meters, and PIM
sets. Peak power meters have up to 70 MHz of video BW, and
40 GHz of carrier BW. Modulation & audio analyzers provide
analog measurements required for radio sets. RF Millivoltmeters
use an RF probe system that automatically loads calibration coefficients
for measurements to 1.2 GHz.
new edition of the
IEEE JobSite career tips is out. If you are not a member or
don't receive their e-mail, here is its contents.
Are Your Company's Hiring
How to Break into the
Once Fired, Now a Founder:
How a Tech Leader Rebuilt
Homegrown Irish Tech
Sector Thinks Differently
to Overcome Talent
Asia-Pacific – Open For
Business, and Tech Jobs
mount adapters for SMA/Female to N/Female. Rugged construction
for repeatability and reliability. Available to ship from stock.
Frequency: DC-18 GHz, Return Loss: Min 25dB (1:1.15 VSWR),
P/N: ADP-3000-322 Material/Finish: Corrosion resistant 303 stainless
steel - passivated, P/N: ADP-3000-322-B Material/Finish: Brass/Nickel,
Contact: Beryllium Copper Gold Plated, Insulator: PTFE. Visit
to request a quote, view product lines and browse our catalogs.
Electronics has published its
December 2013 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 small cell backhaul growth, distributed antenna systems
(DAS) growth, and the large amount of potential for interference
caused by densely populated small cells.
has never happened to me, but I have read many tales of woe from
people who dropped
their cellphones, iPods, Walkmans, etc., into the toilet, a
puddle of mud, or a bowl of soup, or else jumped into a pool or
the ocean with them in their pockets. The results are usually disastrous,
with an expensive repair or replacement bill ensuing. Standard device
warranties do not cover immersion, and indeed most devices these
days contain an indicator strip inside that turns color when moistened,
so there's no way to lie your way into free service. The well-known,
but dubiously successful trick of embedding your device in a bowl
of white rice to absorb the wetness is only good if you happened
to drop it into a glass of demineralized water - something not typically
found in a toilet bowl or lake. Sometimes if you...
Dorr has a unique article on the EDN website titled, "The
Relationship Between Digital Filters and Maintaining Your Front
Yard." In it, he models the feedback system in play for him
that uses critical input from his wife and neighbors regarding the
perceived quality of his lawn to modulated the amount of work he
puts into its maintenance, which results in an acceptable steady-state
level of lush greenness. In the process, you learn a little about
digital filter design. BTW, his dog's name is the same as the
Cahak has more than 25 years of
engineering and test engineering experience. Specialties include
hardware, CAD and software design with extensive capabilities in
process automation, database programming, & graphics. Experience
includes hardware, bench and rack design, environmental, special
fixturing, test interfaces, signal processing, project management,
device control functions, and LabVIEW automation.
Hawkins, of LadyBug Technologies, submitted this short note on the
advantages of modern power sensor circuit techniques for eliminating
the need for internal
zeroing & calibration. Sophisticated factory calibration
and a smart sensor allows fully qualified operation across all rated
power and temperature ranges.
things just shouldn't be done, like converting a World War II
era Douglas DC-3 airplane's engine from its original twin multi-cylinder
radials to jet-engine-powered turboprops; it violates nature's rules.
Another example might be installing a
speedometer in a vintage pickup truck. I say 'might' because thanks
to Luke Miller's ingenuity, his 1953 International pickup truck
- indeed the world - now has a proven plan for a GPS-driven, two-digit
speedometer featuring a Nixie tube numerical display. A two-part
article on the EE Times website provides the theory of operation
and the details for constructing the Nixie tube speedometer. Why
GPS-driven, you might ask...
Model No. PE2-28-218-5R0-12-15-SFF is a 2.0 to 18.0 GHz,
low noise amplifier that provides 24 dB min of gain. The
noise figure is 4.5 dB max and offers an OP1dB of 14 dBm
min. The operating voltage is +15 VDC and the current draw
is 200 mA max. The unit is supplied with removable SMA(F) connectors
in our standard PE2 housing.
good folks at Fotofab have been helping to deliver RF Cafe to
you since 2009. Fotofab was founded in 1967 to offer the cost and
delivery advantages of photochemical
- including RF / EMI
shielding enclosures - to manufacturers of electronic and electrical
equipment for high tech industries - aerospace, microwave, automotive,
computers, communications, medical and controls, to mention a few
of the most prominent.
Microwave Corporation has announced a new E-band MMIC power detector
that is ideal for communications systems, test equipment, sensors
and general purpose RF detection over the 71 - 86 GHz frequency
HMC7447 power detector provides a linear output voltage over
a -0.5 to +23.5 dBm input power range with low insertion loss of
0.45 dB and typical input return loss of only 19.5 dB. Ideal for
monitoring transmitter operation or enabling closed loop transmitter
output power, the detector exhibits excellent sensitivity and a
frequency response of ±0.2 dB over the 71 to 86 GHz frequency band.
The HMC7447 power detector also provides excellent repeatability
and flat performance over varying temperature and output load variations.
Waveform Generation, by Dr. Pete Symons. This overview
introduces powerful, flexible and practical digital waveform generation
techniques, enabling the design of bespoke digital waveform generation
systems from scratch. Including detailed hardware design examples
and downloadable Mathcad models created for 'what if?' design scenarios,
this is essential reading for professional members of the digital
signal processing community. Peter Symons is a professional engineer
with over 30 years of experience in the design of digital and analogue
signal processing systems and is Chief Engineer at Avalon Sciences
has been a leading provider of
RF & microwave
noise generating equipment used in commercial & military
applications since 1985. We
noise diodes, calibrated noise sources, jitter sources, cryogenic
noise standards, and computer controlled instruments for either
precision C/N, or broad band white Gaussian noise. Noise Com provides
off the shelf as well as custom designed noise testing solutions.
International Geophysical Year (IGY)
ran from July 1957 through December 1958 and was designed to promote
cooperation between countries in the earth sciences realm of research.
In all, 67 countries participated in various IGY projects. China
declined involvement based on objections to Taiwan being involved,
arguably perpetuating its people's languishing behind the Iron Curtain
of Communism much longer than it otherwise would have. Global studies
were carried out for the aurora and airglow, cosmic rays, geomagnetism,
gravity, the ionosphere, longitude and latitude determinations,
meteorology, oceanography, seismology, and solar activity. It was
during this period that the USSR launched Sputnik and the Van Allen
radiation belts were discovered. This article reports on the radio-communications-related...
Schwarz has published a really nice tutorial
(aka app note) on how to set up and
measure vital parameters on
satellite upconverters. The nice thing about this article is
that it not only goes into great detail in how to use the many specialty
features of the company's network and signal analyzers and signal
generators, but it also spends a lot of time reviewing the concepts
of intercept points, intermodulation distortion, group delay, frequency
mixing and conversion, frequency conversion, noise power, compression
points, spurious emissions, and more. If you are new to RF upconversion
system design, then this is a good place to start your education.
of Fredericksburg, Virginia, is the October
Book Drawing winner. I was late in picking winners due to all
the books being in storage during a household move. Tom wisely selected
Conquer Radio Frequency, by Dr. Francesco Fornetti. Dr.
Fornetti graciously donated a copy for the contest. Conquer
Radio Frequency was used as the basis for an
RF Cafe Quiz.
R&S MMHS message handling system from Rohde & Schwarz
will be an essential part of the UK Ministry of Defense's naval
communications network at their Forest Moor, Kinloss and overseas
sites. The contract will be part of the UK MoD’s defense high frequency
communications service project (DHFCS).
DHFCS is a public-private partnership (PPP)
that was awarded to Babcock in 2003 for a 15 year period. The purpose
of the project is to deliver strategic beyond-line-of-site high
frequency (HF) and low frequency
(LF) communications services...
the leading online website for RF & Microwave products, has
announced the release of a section dedicated to GPS/GNSS – The section
GPS Antennas and
GPS Modules from over 25 companies, and provides a parametric
search tool that will help you narrow down on the products by frequency
band, supply voltage, gain, noise figure and a number of other parameters.
This is the first of series of application sections that are planned
on everything RF. Coming up shortly will be sections for Bluetooth,
WiFi, RFID, CATV and a number of other applications.
do you think you get more radiation from, leaning up against an
atomic reactor or your wife? ... I don't want to alarm you, but
all human beings have radioactive potassium in their blood - and
that includes your wife. This reactor may have more radioactivity,
but much greater shielding. If you compare the two for radiation,
you get just a bit more from Dresden III than from your wife."
Dr. Edward Teller ("father of the hydrogen
bomb") at Atomic Energy Commission hearing concerning Dresden III
reactor in Illinois.
this latest installment of EDN's
"Tales from the
Cube" series, electrical engineer Larry Baxter recounts his
experience as a neophyte circuit designer for a numerical display
project and how it helped decades later when working on a dielectric-paper
photoprinter circuit. It involves a high-voltage signal generator
and the importance of synchronizing system processes to minimize
noise and facilitate testing. A lot of good lessons are crammed
into this one example of how being creative and having the ability
to get the job done on your own is a good thing, but having access
to and heeding the learned guidance of senior engineers can save
a lot of trouble down the line and result in a superior product
to boot. My interest, of course, was immediately piqued to the Apollo
program, but the story is very much worthwhile reading for any designer.
Schwarz is one of the world's leading manufacturers of
and broadcasting equipment. With
than 8700 employees and representatives in more than 70 countries,
and world wide sales of almost $2.3B (€1.8B), we are able to
support customers both globally and locally.
Vector Signal Generators. Analog, RF, microwave, and digital
signal generators with a variety of frequencies, standards, modulations,
and functions at up to 43.5 GHz.