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 to ask..."
Yep, 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
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
magazine ran a short feature titled "Outer Space, Indoors," in the January 2013
edition. The main photo is a shot of the inside of the
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.
is a valued supplier of high quality RF
and microwave passive components in the frequency
range 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 dividers.
"Scientific 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
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 January.
Skyworks 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.
Here 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.
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.
NP 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 reliability.
This is another item that appeared in the December edition
of a local publication by The Good Life Press.
"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 back to...
I 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...
AWR 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.
This 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
‡ I am adaptable:
I've changed jobs a lot.
I am on the go:
I'm never at my desk.
highly motivated to succeed:
The minute I find a better job,
I'm outta there.
‡ I have formal training:
I'm a college drop-out.
‡ I interact well with co-workers:
I've been accused of...
Phase Matrix designs and manufactures RF and
microwave test & measurement (T&M)
instruments and components and is a subsidiary of National Instruments. We proudly
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
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.
PMI Model No.
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"
The 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 work..."
Here 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
from RF Cafe
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.
Here 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
David Bowie, and Casting
Crowns. Watching the instruments being played really enhances the effect of the
Skyworks Solutions has introduced a 0.7-1.2 gigahertz,
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
Hofstadter's Law: "It always takes longer
than you expect, even when you take into account Hofstadter's Law." -
(hat tip to Gary S.)
Deadbeat 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...
have ever dreamed of having your own atomic-driven pocket 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
tech words & clues)
Skyworks 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
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.
Jyebao, 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 rotational angles.
I 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" (1942), "Power
Supply" (1944), "Pre-Radio"
(1944), "A Radioman's Nightmare" (1945).
Prism 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
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
Boonton 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.
A new edition
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
Business, and Tech
VidaRF now offers
flange 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 VidaRF
today to request a quote, view product lines and browse our catalogs.
Anatech 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.
It 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 Bumstead
dog's name. Enjoy.
has more than 25 years of design 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
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
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
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...
PMI 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.
The 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
machining - 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.
Hittite 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 range. The
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
Digital 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
Noisecom has been a leading provider
of RF & microwave noise generating equipment
used in commercial & military applications since 1985. We
provide 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
RF Cafe 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
everything RF, the leading online
website for RF & Microwave products, has announced the release of a section
dedicated to GPS/GNSS – The section currently covers
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.
"[W]hat 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.
In 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 on
Apollo 11 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.
Rohde & Schwarz is one of the
world's leading manufacturers of test &
measurement, communications and broadcasting
more 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.