new white paper from AWR, "RF/Microwave
EDA Software Design Flow Considerations for PA MMIC Design,"
examines a gallium arsenide (GaAs)
pseudomorphic high electron mobility transistor
(pHEMT) power amplifier
(PA) design approach from a systems
perspective. The design flow and its essential features for most
PA design projects is illustrated through the design of a simple,
Class A GaAs pHEMT monolithic microwave integrated circuit
(MMIC) PA using AWR’s Microwave Office®
high-frequency design software.
USA also sends out their "today's engineer" newsletter on Fridays.
Here are some items that strike my fancy.
An Easy Secret for Better
What Keeps Engineers
from Advancing in Their
Engineering Hall of Fame:
Newton famously said, "If I have seen farther it is from standing
on the shoulders of giants." His statement was figurative, of course,
but I can now say literally that I have stood on the shoulders of
a giant. Somewhere recently, I don't recall where, I read that although
American Radio Relay League (ARRL) founder
Hiram Percy Maxim was born in New York and spent most of his
adult life in Connecticut, he was buried in Rose Hill Cemetery located
in Hagerstown, Maryland. That just happens to be where Melanie and
I stop a couple times each year to visit her mother. We lived there
ourselves for about three years in the early 1990s. That day, I
surely stood if not exactly atop Mr. Maxim's shoulders, then very
nearly so as I maneuvered to take this picture of his grave marker.
Why is he buried in Maryland, you might ask? That is where his...
a few new headlines for you from LinkedIn, in case you don't receive
their weekly update. They usually have some pretty good stuff. I'm
not big into the social media scene, but LinkedIn is kind of like
Facebook with a brain required for participation.
Upskilling for Career
Who's Your New Mobile
Carrier? How 'Bout Wi-Fi?
5 Things You Have to
Unlearn to Succeed at Work
Every Step You Take,
Every Move You Make
You've Got the Degree,
Now Get out the Passport
LLC is a global supplier of
Microwave components. Their products include SMT hybrid
couplers, wire bondable passive components, coaxial products, test
fixtures and very useful test boards for evaluating components.
The Electro-Photonics team can support your small R&D design
requirements with RF & Microwave test fixtures and
save you valuable design and characterization time.
extraterrestrial threat to existence, be it an impending asteroid
strike or an intelligent being's announced intention to do harm
to the earth, would probably be required these days to invoke the
sort of voluntary personal sacrifices of today's average citizen
that was exhibited in the enthusiastic, patriotic response by Americans
'V' for Victory campaign during World War II.
You no doubt have seen pictures of kids pulling wagons filled with
metal scrap, rubber tires, and glass milk and pop bottles collected
for the war effort, and pickup trucks piled high with sections of
pipe, car parts, and retired furnaces. Resources were relatively
scarce at the time, and material was being consumed very quickly
in the effort beat back the aggressive advances of Axis forces throughout
Europe, northern Africa, and the South Pacific. This article from
a 1942 edition of Radio Retailing Today encouraged radio
repairmen to check with customers during service calls...
is a well-know name amongst electronics technicians and engineers
who have been in the business for any length of time.
Triplett meter movements (aka panel meters)
were considered to be top-of-the-line product in the days before
digital meters and displays. They were used in industrial instrumentation,
in military equipment, and in amateur radio gear. Triplett is still
in business today but it appears they no longer sell just meter
movements, although there is a large supply
(new and used) available on eBay and
Ham radio websites and swap meets. This advertisement for Triplett
Thin-Line Instruments appeared in the September 1942 edition of
Radio Retailing Today magazine.
Solutions, Inc. unveils a new device for cellular infrastructure,
VHF/UHF military and public safety radios. The SKY12408-321LF is
a 50-600 MHz, 6 dB
differential attenuator that is pin-for-pin compatible with
its 12 dB SKY12407-321LF attenuator, but ideal for IF radio
applications requiring lower overall attenuation and gain control.
The new solution also offers a novel differential I/O design and
fast settling time for applications that down convert to a low Intermediate
was one of those, "Well, huh!," moments for me when I read in a
story from the IEEE that claims the first recorded use of the term
'bug' in reference to a problem in hardware was not by U.S. Navy
Admiral Grace Hopper and her colleagues, as popular belief
(including mine) goes. Their finding
of a dead moth - a 'bug'
- in a Harvard University computer is legend, but evidently was
not the first known instance. Instead, it was none other than Thomas
Edison who may have originally used the term. Before you go accusing
the respected Institution of waging a War on Women
(a popular indictment of convenience these
days) for denying credit where credit is due, nobody is implying
that she purloined Mr. Edison's term. According to researcher Dr. Paul
Israel, editor of the
The Papers of Thomas A.
Edison, and the IEEE History Center, Edison regularly referred
to technical problems as bugs. "In 1873 Edison first confronted
what he later called a bug when he began developing a quadruplex
LLC announces the availability of Y2D-900R, a
power 2-way SMD power divider / combiner. Our new
Y2D-900R power divider/combiner operates from 700-1000 MHz
and can dissipate up to 350 W in a small 480 mil x 650 mil
package. This power divider offers excellent isolation, low
insertion loss, and good phase balance for most critical applications. The
Y2D-900R requires an external 100 ohm resistor for operation. Power
will only be limited by the size and power ratings of the chosen
Instruments designs and manufactures the world's finest high-precision
Delay Line (PDL) instruments and
modules. All instruments are fully programmable via GPIB interface,
and are suitable for use in high frequency RF signal applications
as phase shifters or where an extremely high precision and accurate
amount of delay is required. Colby Instruments has been helping
deliver RF Cafe since 2009.
radar technician Elbert Cook just sent some photos of the
TPN-19 radar units that were based with him at the 3rd Combat
Communications Group (aka 3rd MOB, aka 3CCG)
at Tinker AFB, Oklahoma. He also sent the first couple pictures
of a scale model of the
radar unit that he has begun. Stay tuned for project updates.
has introduced a
high power 30 dB coupler with a 2-4 GHz frequency
range (other coupling values available).
Average power is 500 W, with a Peak of 8 kW. Loss is 0.25 dB
(excluding coupled power), directivity
is 18 dB, and VSWR is 1.30:1. Connector type is "N" Female
on all ports. Custom designs available upon request. VidaRF
offers a wide selection of Directional Couplers, Dual Directional
Couplers and Hybrid Couplers, designed to cover 0.1 GHz to
fair number of people who visit RF Cafe have at some point been
involved as an Expert Witness for a court case involving product
liability and/or IP ownership or infringement. They quickly learn
how important it is to
competent and renowned legal representation.
is a law firm specializing in expert witness cases. Every month
or so they send me an article about specific court cases that could
be of interest to RF Cafe visitors. This particular article is titled
"Fortune Telling & Reliability? An Expert Testimony Enigma."
It illustrates how dicey the process of selecting appropriate Expert
Witnesses can be for legal teams - especially given the subjective
nature of judges who decide on admissibility of evidence.
Technology Innovation announces the immediate availability of very
composite DIN 7/16 connectors. The body material is a composite
plastic black with silver-plated bronze contacts, as opposed to
a standard brass body and beryllium-copper
(Be-Cu) contacts. This newly developed 7/16 connector is
seeing a steep increase in use in leading countries like Japan,
Germany, and the USA.
former comrade contacted me recently to say he, too, had moved on
from where we used to work. He is a very capable RF engineer and
is now retired from his 20+-year
stint as a communications officer in the Air National Guard. Parsec
Technologies is now the beneficiary of his know-how. He recommended
that they try advertising on RF Cafe and the result is this announcement.
Thanks Conrad! Parsec's LNAs have been designed to optimize GaAs
for the ultimate combination of noise figure, gain, and IP3. We
are redefining what
amplifiers are in today's market for low voltage, low power
amplifiers with low noise, high gain and high IP3 normally found
on amplifiers that consume much more power.
texts must have been a real challenge on this early portable phone.
Aside from having to type out your message on a standard telephone
keypad (oh, the humanity), the baud
rate must have been snail-like. The article doesn't mention whether
dropped calls were a big issue and whether there was a massive marketing
plan with a bespectacled "Can You Hear Me now?" guy. I'm just kidding,
of course. This news item appeared in a 1955 edition of Air
Trails: Hobbies for Young Men. Before you laugh at the
dipole antenna and carrying case, consider that it was only a little
over two decades ago that Motorola debuted its famous M800 'Bag
Phone.' From the magazine: "Portable two-way radio phone...
is a world leader in the design and development of surface mount
VCO modules & PLL
frequency synthesizers for the commercial microwave/RF wireless
market. RoHS compliant signal source products currently range from
40 MHz to 13.5 GHz bands. PLLs available in integer, fractional-N
and single frequency models. VCOs feature coaxial resonator based
and high-Q distributed resonator construction.
and Repairing Commercial Electrical Equipment, by David Herres,
is another in a series where he has leveraged his many years working
as a Master Electrician. It is his first work that offers a practical
approach to diagnosing and repairing commercial / industrial electrical
equipment – covering everything from motors, computers, elevators,
and fire alarm systems to heavy-duty ovens and audio equipment.
This one-of-a-kind guide can help you become more competent in your
profession. Inside you'll find ways to become faster, more efficient,
and able to achieve a much higher success rate in restoring large
electrical equipment without damaging it, introducing an additional
defect, or creating a hazard.
don't seem to be many electronic products these days without some
form of software in them (EEPROMs, ASICs, μProcessors,
FPGAs, etc.); indeed, many electrical engineers also wear
a software engineer's hat. Two consultants that advertise on RF
Cafe, Lance Lascari (RF
Dude) and Joe Cahak (Sunshine
Design) come to mind, along with many others known during
my career. I've even done a bit of software and FPGA programming
myself. This installment of EDN's "Tales from the Cube"
series involves an engineer who needed to live in both worlds in
order to solve his problem with a meter designed by someone long
gone from the company. Mihaela Costin applied a bit of ingenuity
to make the best of a bad situation...
Assembly Builder tool on everything RF lets you specify
your cable assembly requirements in a form and on submission directs
it to over 20 companies that can manufacturer it. Your query will
be directed to the leading cable assembly manufacturers – Aeroflex,
Emerson, Amphenol, San-tron, RF Industries, VidaRF, Pasternack,
SV Microwave and many others. You no longer need to send out individual
request to each manufacturer - everything RF does that for you.
The tool has been optimized for Desktops, Tablets and Mobiles so
you can use it from anywhere on any device.
Electronics has released new designs for a 710-716 MHz / 740-746 MHz
bandpass combiner , 779 MHz / 749 MHz ceramic duplexer
, and a 1710-1755 MHz / 2110-2155 MHz cavity duplexer.
All can be ordered directly through their
AMCrf web store.
Davis sent me a link to Mike Yancey's
(KM5Z) website where there is a scanned version of the 1948
National Radio Institute (NRI) home
study course for radio technicians. It is a very extensive collection
of 55 volumes (PDF format) covering
topics like Simple Radio Circuits and Meters, Radio Coils and How
They Work, How Detectors Work in Radio and Television Receivers,
Current, Voltage and Resistance Measurements, and How to Eliminate
Man-Made Interference. KM5Z also has some other good content that
you might be interested in while you're there like a 1958 edition
the RCA Radio & TV Course, online calculators for toroids, inductor
Q, voltage dividers, and antenna field strength, and radio restoration
Power Products, Inc. has more than 25 years of experience designing
RF Passive Components.
Our couplers, combiners, resistors, and terminations incorporate
the latest technology in materials available, which equates to unrivaled
product performance. IPP has been with RF Cafe since early 2008.
Product Digest just posted articles from their August edition.
Lots of good stuff there, as usual.
How to Calculate Peak
Uncertainties, Sook H. Wong
Conducting Noise Figure
Measurements, Sean Flavin
EMC Test Equipment and
Services Market – Another
Opportunity in China,
USB Brings Portability and
Flexibility to MW Test Bench
– Wherever it May Be,
Building Low PIM Coax
Assemblies with Consistent
old, something new, something borrowed, something... brown. My paraphrasing
(lamely) of the old saying for bringing
good luck to a bride aptly describes Adam Vaughan's effort in building
his 'Twittertape Machine.'
Adam's machine prints out Twitter messages on a paper tape in the
manner of early stock market tickers. "This astounding device will
print a permanent copy of all Tweets yet requires no ink or computer."
So says a proclamation in vintage serif font and decorative trimmings
on the website's homepage. Indeed it does. The prototype uses two
wall wart AC/DC adapters, an Arduino-style microcontroller with
an Ethernet interface, a Bell jar, a thermal printer, and miscellaneous
clock parts. Full details of the design and operation are provided,
including a video. It checks for and prints out available Tweets
every 30 seconds. Before you get upset about altering historic relics...
you think it's expensive to hire a professional for a job, wait
until you hire an amateur." -
famous global firefighter. Red Adair is the guy who put out all
the Kuwait oil well fires after Hussein's troops ignited them while
retreating from occupied territory. Television 'experts' said those
fires would burn for decades. They were out in months.
a break and work this week's
wireless engineering themed crossword puzzle. All the words
are pulled from a hand-built list of terms, names, and abbreviations
that have only to do with science, mathematics, and engineering.
If you want a crossword with names of movie stars and obscure countries,
try the local newspaper. If you want to exercise your nerd knowledge,
this is the one for you.
PEC3-40-30M26R5G-6R0-12-12-SFF is a 30 MHz to 26.5 GHz
Low Noise Amplifier that provides greater than 35 dB of gain
while maintaining a maximum gain flatness of ±3.5 dB maximum
over the operating frequency. The noise figure is 6.0 dB
typical and offers an OP1dB of +12 dBm minimum. The operating
voltage is +12 to 15 VDC and the current draw is 700 mA
going to love this installment of Sherlock Ohms. Even if you have
never had to deal directly with customers for a product performance
issue, you will easily empathize with engineer Jonathan Eckrich
in "The Case
of the Confused Customer." The incident reminds me of a story
I read years ago by an engineer who worked on development of one
of the early computer languages - I think it was FORTRAN. The user
called to complain that a section of code was failing and demanded
assistance because in his opinion, the language kernel was faulty.
The caller's name was not disclosed, but the engineer said he was
a notable figure. After listening to the problem, the cause seemed
obvious, so the engineer (wish I could remember
his name) instructed the guy to make sure he was using the
"less than" symbol, to which the guy responded that he is no idiot
and the problem must be something else...
challenge you to find a calculus lesson in a modern-day electronics
magazine. In 1932, not all that long after Isaac Newton developed
differential calculus (that's a joke), Radio News magazine
ran a series of "Mathematics
in Radio" articles that included, among other topics, a few
lessons in calculus. Anyone who has taken college-level science
or engineering courses knows how indispensible calculus is in working
out many circuit, physics, and chemistry problems. My appreciation
for calculus came when I realized that it actually allowed me to
derive the kinds of standard equations that are commonly seen in
lower level applications. For instance, if you needed to know the
volume of a sphere, you could look up the familiar Volume = 4/3 π r3
formula, or you could write the equation...
Corporation, the innovation leader in high-frequency EDA software,
gifted its software to the winners of the High Efficiency Power
Amplifier (HEPA) and Software Defined
Radio (SDR) Student Design Contests
offered at the 2013 IMS MTT-S conference. The gifts are part of
AWR University Program, which sponsors student design contests
throughout the world to encourage students to become involved in
the dynamic profession of microwave and RF engineering and to apply
their knowledge to practical designs using the highly efficient
AWR design methodology.
is the latest bunch of engineering career and employment news headlines
from IEEE's JobSite.
Slideshow: Special Report:
Silicon Valley's Dirty Secret
- Age Bias (it ain't just in SV)
Layoff Taboo: Japan's
5 Global Recruiting Trends
to Help You Land Your
Does Your Entry-Level Job
Have Growth Potential?
Here are a couple more I found while looking
Confidence on the Rise
Five Ways Job Seekers
Can be Proactive While
Engineering Grads Enjoy
Greater Job Prospects
The Myth of America's
Missing Software Engineers
Jin Technology Innovations helps to deliver RF Cafe through their
advertising, which was just renewed for another term. Dong Jin designs,
manufactures, and assembles
cable assemblies and components. Competitive price, on-time delivery
and best quality. No minimum order size. One-day delivery. ISO9001,
ISO14001, RoHS certified.
is another great RF troubleshooting saga; in fact, it would make
a good short action film. Designing and implementing proper
lightning protection can be a real challenge - and quite expensive.
Lightning has a nasty habit of seeking out and exploiting weaknesses.
Author Rod Hine doesn't cite improper protection as the culprit
for causing his woes in his telling of, The Case of the "Earth
Station Stopped by Lightning." A couple decades ago I worked
with a team that designed a prototype weather radar system with
cobbled-together parts that included a surplus military phased array
antenna. After doing all the initial design, build and test at our
facility, everything was moved to an open air site that sat at the
top of a ridge which was known to attract lightning like trailer
parks attract tornadoes. A fair amount of effort went into lightning
mitigation over the years, so we felt comfortable hooking into the
existing system. All went fine for the remaining time I was there.
About a year later...
being contacted by a friend of mine who works for
about adding their company to my categorical
Manufacturers and Services
pages, I realized that I blinked and missed the need to add resources
for the relatively new fields of
Software Defined Radio,
White Space, and
Mobile HDTV. Having just awoken, there are now the beginnings
of pages for them. In searching for companies to include it quickly
became apparent that most of what is available to fill the need
is re-purposed ICs and hardware, but as the technologies mature
and standards are established there will be more specialty products.
Parsec Technologies is one of those companies working now to fill
has introduced a low loss
Waveguide Isolator, model VDWR42-2021-A, with a frequency range
from 20.2-21.2 GHz. The isolator offers 0.1 dB loss, isolation
28 dB, VSWR of 1.11:1. Forward power handling is 3 watts with
operating temperature -40 to +80 C. Pressure sealed to 10 psi.
radios in the family car became a standard accessory, a push ensued
to make them cheaper, more reliable, and service-free. A major Achilles'
Heel was the high voltage power supply required to energize vacuum
tubes. Known as vibrator power supplies due to using an oscillator
to convert the battery's 12 DC supply (some
autos still used 6 V systems) into AC that could be
transformed up to the 300 volts used by most tubes of the day, most
early failures were attributed to the circuits. They also caused
annoying noise in the audio output if careful filtering and installation
was not performed. Having been invented only a couple years earlier,
transistors were being designed into the power supplies, but low-voltage
tubes were still needed for the electronics. In response to the
demand, low-voltage tubes were created to fill the gap until acceptable
transistors became available for a fully solid-state radio. This
article discusses some of the problems with
low voltage tube design and methods employed to overcome them.
Design for Active Sensing Systems: A Computational Approach,
by Hao He Hao He, Jian Li, and Petre Stoica, is my Featured Book
for this week. With a focus on developing computational algorithms
for examining waveform design in diverse active sensing applications,
this guide is ideal for researchers and practitioners in the field.
The three parts conveniently correspond to the three categories
of desirable waveform properties: good aperiodic correlations, good
periodic correlations and beam pattern matching. In addition to
numerical results, the authors present theoretical analyses describing
lower bounds or limitations of performance.
Cambridge University Press.
so now I have read about someone who credits social media - LinkedIn
specifically - for success.
Judy Warner, of Transline Technology, responded to the "Fake
Twitter Follower Factory" commentary that I posted on LinkedIn
to say she has had an overwhelmingly good response from reaching
out to and engaging the LinkedIn community of engineers. In fact,
Judy's experience was so spectacular that in a few short years she
went from being a connectionless marketing exec re-entering the
PCB marketing realm after a decade-long hiatus, to being a sought-after
expert in her field. Read her short article "Does
Marketing Matter?" in the April 2013 edition of the pcb
magazine (page 62). Maybe Judy's feedback to my LinkedIn post
means I, too, can now claim social media success!
always been a bit dubious about the whole social media thing. Yes,
it can be a great medium for connecting with old friends and maybe
getting some breaking news, but otherwise services like
Twitter seem to
mostly be a time-wasting enabler for people with too little meaningful
purpose in their lives. Achieving the largest number of 'Followers'
is now a lifetime goal in order to assert and prove popularity and
dominance in society. Catering to vanity is big business so as you
might expect, there is a plethora of opportunists who offer to inflate
the Followership of gullible Twits. A recent story in Inc magazine,
one of many such stories in many news reports, illustrated just
how easy it is given even a modest cash outlay to buy Followers
- some charge as little as a penny apiece. If you are thinking of
starting a Twitter Follower business of your own, businesses will
also sell you 'verified' e-mails address batches, Captcha defeaters,
and HideMyAss.com will...
I mentioned how much I appreciate good graphs and illustrations
for conveying information? Yeah, I guess I have... often. The adage
about a picture being worth a thousand words certainly holds true
- even if the thousand words inadvertently describes the artist's
crappy attempt to get his/her message across. This particular graphic
presents information on some of the vast resources of [mostly] free
online educational sources for engineering and related topics.
Online Courses (MOOC) was launched in 2008 at the University
of Winnipeg and is credited with birthing the idea (at least for
being the first to successfully implement it). There are, of course
even more courses in other areas of interest. Flight vehicle aerodynamics,
astronomy, solar energy, physics, numerical statistics, even sci-fi
and creative writing, all useful in a well rounded engineering experience,
are among the listed types...
writers at Test & Measurement magazine hit a high note
this month with articles. Enjoy.
Components Meet Specs
by Jeffrey Dierker
and Reliability Degradation
Issues, by T. Nishimura
Improve Wireless Testing
of Sensitive Devices,
by Per Nielsen
Repair is based in Cocoa, Florida, and focuses on servicing
network analyzers. "All of our technicians are military PMEL
graduates." After their tenure, they spent time in R&D labs, USAF
PMEL labs, and commercial calibration labs. Repair calibration services
for new equipment & extend life of obsolete high performance
acquisition is the end of a dream." - Jake Lodwick, co-founder of
Vimeo. This quote appeared in the July/August 2013
Inc magazine, where Mr. Lodwick describes the Heck he went
through with his company. He further states, "If you truly believe
in the potential of your company to change the world for the better,
there's no excuse for settling for an acquisition."
a break and work this week's
engineering themed crossword puzzle. All the words are pulled
from a hand-built list of terms, names, and abbreviations that have
only to do with science, mathematics, and engineering. If you want
a crossword with names of movie stars and obscure countries, try
the local newspaper. If you want to exercise your nerd knowledge,
this is the one for you.
do you think of the USAF's plan to deploy a band of
millions of tiny dipole
antennas into orbit around Earth for communications support?
Because over-the-horizon (OTH) radio
communications rely on the upper atmosphere being conductive to
reflect radio waves, it is essential that there always be something
for bending signals back to Earth rather than allowing them to escape
into space. The ionosphere has many identified regions that
do a good job of reflecting signals of certain wavelengths during
particular times of day and under special atmospheric conditions
cause by solar activity. There are times when reliable OTH communications
are not possible because of severe coronal mass ejections
(CMEs), high meteoric activity, and
even terrestrial events like major volcanic eruptions. Even predictable
variation in ionosphere characteristics like the diurnal blending
of the F1 and F2 layers into a single F layer complicates emergency
and strategic communications planning...
BRL Test and their
division are helping to deliver RF Cafe by advertising. BRL Test
Analyzer Repair specializes in the repair of spectrum and network
analyzers. They are a leading dealer of new and reconditioned test
and measurement equipment. They buy, sell, rent, lease, repair and
calibrate all types of general purpose test and measurement equipment.
witnesses play a big role in most of the court cases that get reported
ExpertServices is a law firm specializing in expert witnesses.
Every month or so they send me an article about specific court cases
that could be of interest to RF Cafe visitors. This particular article
is titled "Can
Expert Statements Inadvertently Waive Protection?" It the case,
an expert witness used by Company A to compel Company B to submit
to claims was not intended to be used in court and so per Company
A, he/she should not be able to be deposed during the discovery
phase of the lawsuit (it involved faulty materials
in a transmission). The expert witness' opinion was quoted
but not declared as evidence. The laws pertaining to testifying
and non-testifying experts are, as you might imagine, complex and
prone to the subjective whims of courts even though most might consider
the codified law to be quite clear. The lesson here is to be careful
how expert witnesses are handled, even if you have no intention
of using their opinions in court.