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 band...
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 me know.
- In Defense of
Lamenting Bell Labs,
Tapping into a New RF
Energy Source Found in
Digital Processing Circuits,
Detecting ESD Events
- Active Antenna Systems
Enjoy Growth, Iliza
RF Technology in Semi
Popular Science 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.
Pulsar Microwave 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.
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
This 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 January.
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
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.
Popular Electronics ran
a 5-part series on test equipment usage. This installment is on the use of a vacuum tube voltmeter
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.
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
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
This 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 back to...
I am not of the Occupy Wall Street
(OWS) mindset, but an honest assessment of the
income disparity 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...
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
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
interpret 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
‡ My background and skills match your requirements: You're probably looking for someone more experienced.
‡ I am adaptable:
I've changed jobs a lot.
‡ I am on the go:
I'm never at my desk.
‡ I'm 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...
designs and manufactures RF and microwave test & 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.
CP 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
In 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.
Model No. 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"
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
(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
Here are a few of the latest circuit design and theory articles from electrical engineering
Phase Noise and the
Y-Factor Noise Figure
Use a Heated Diode
a Flow Sensor
H-Bridge: Black Box Or
Are Details Important?
Marketing for Engineers
• The Future of Interposers
for Semiconductor IC
You Know Your
from RF Cafe
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
Bowie, and Casting Crowns. Watching the instruments being played really enhances the effect of the song.
Skyworks 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
Hofstadter's Law: "It always takes longer than you expect, even when you take into
account Hofstadter's Law." - Douglas Hofstadter
(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...
If you 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
(only 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 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.
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), "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
of 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'
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
test 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 of the
IEEE JobSite career tips is out. If you are not a member or don't receive their e-mail, here is its
- Are Your Company's
How to Break into the
Once Fired, Now a Founder:
How a Tech Leader Rebuilt
Sector Thinks Differently
to Overcome Talent
- Asia-Pacific – Open For
Business, and Tech Jobs
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...
Barry 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.
Joe Cahak 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.
Orwill 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
digital 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
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
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 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.
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 Ltd.
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.
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...
Rohde & 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.
Tom C., 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
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.
"[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 the
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 equipment. With
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.
Generators. Analog, RF, microwave, and digital signal generators with a variety of frequencies, standards, modulations,
and functions at up to 43.5 GHz.