Going Wireless
Linx Technologies has published a white paper
titled, "The FCC Certification Process: Going Wireless." Author Justin
Hopper writes, "The FCC certification process for products with wireless features
can be complicated and daunting. Increasingly, customers are expecting wireless
features, yet many manufacturers hesitate because of the uncertainty of the certification
process. This article discusses the FCC certification process for the United States
and shows that it is not as bad as it may seem. Other countries have different processes
and procedures, but that is beyond the scope of this article...<continued> " This article is one of the
first entries in Linx's
new Blog.
Accreditation for ISO/IEC 17025
Advanced Test Equipment Rentals (ATEC),
supplier of complete testing solutions for EMC applications in military/defense,
telecommunication, commercial CE, aerospace and automotive markets, today announced
it has been awarded ISO/IEC 17025-2005 &
ANSI/NCSL Z540-1-1994 accreditation for calibration by the American Association
for Laboratory Accreditation (A2LA). Accreditation to ISO/IEC 17025
is obtained through an assessment of a laboratory's compliance in carrying out specific
tests and calibrations precisely to the scope of accreditation.
Back in the 1960s, Robert Balin created many
quizzes on various electronics topics for Popular Electronics magazine.
I have already posted a couple dozen of them. Here is the latest one on the subject
of
Units of Measure commonly found in electronics work. I missed
the one for the tape deck, but then I don't ever remember concerning myself with
the electrical and magnetic characteristics of tape decks.
Success with AWR
The Czech Technical University (CTU)
in Prague challenges its graduate engineering students to master the basic design
of microwave circuits and subsystems and become familiar with the concepts of active
and passive microwave and millimeter wave circuit designs. CTU uses AWR's
Microwave Office circuit design software and AXIEM EM simulation
software extensively in both coursework and research because it is fast to learn
and easy to use, enabling students to successfully master the complex concepts of
high-frequency design.
Test Equipment Rentals
Advanced Test Equipment Rentals has signed on to help deliver RF Cafe to you
through paid advertising. ATER provides the latest models of
test and measurement equipment
from top name manufacturers like Agilent, Fluke, Anritsu, R&S, Tektronix, and
Yokogawa. Our primary focus is providing a complete rental solution of test and
measurement equipment to industries such as Aerospace, Defense, EMC, and Communications.
Techniques for the Hobbyist
I suppose the term "Subminiature" as it applies
to electronics components is as relative as the word "Modern" is in book titles.
They might be accurate at the time of the writing, but passage of time renders them
ambiguous. Subminiature in 1957 meant anything other than full-size vacuum tubes,
huge power transformers, multi-layer wafer switches, and hookup wire larger than
AWG 20. The advent of
peanut tubes, very early versions of transistors and solid state
diodes, and ever-higher operational frequencies permitted component sizes to be
shrunk by a factor of two or more. Rather than using a pistol-style soldering gun
or a soldering iron designed for assembling copper guttering, a precision pencil-type
iron could be used and greasy tools from the garage no longer sufficed for turning
screws and nuts. A lot of the material in this article is still useful for hobbyists
and even electronics professionals in the lab.
USAF Radar Tech Hall of Fame
OK, so the Radar Tech Hall of Fame is an RF
Cafe creation, but the USAF hasn't done it and the world deserves one. Our newest
inductee is MSgt. Floyd
Hinkson, ret. Floyd had quite an extensive career working on primarily mobile
radar systems including the MPN-1, MPN-11, MPN-13, MPN-14, and TPN-19. I'd say he's
probably one of foremost authorities on tube-based mobile radars (although the TPN-19
is solid-state). Floyd encourages his fellow radar techs to get in touch. If you
send me an
e-mail, I'll forward it to him.
Satellite Comm Equipment
Z-Communications announces a new RoHS compliant
VCO model CRO1320A-LF for the SATCOM market. The CRO1320A-LF is designed
to cover 1320 MHz with a tuning voltage range of 0.5 to 4.5 Vdc. This
single frequency, high performance VCO has been optimized to feature extremely low
phase noise of -120 dBc/Hz @ 10 kHz offset while operating off a 5 Vdc
supply and typically drawing only 29 mA of current. Output power of 3±3 dBm
into a 50 Ω load while operating over the extended commercial temperature range
of -40 to 85ºC.
Sponsor Nova Microwave
Nova Microwave is a leader in technically differentiated electronic and radio
frequency ferrite circulators
and isolators that connect, protect and control critical systems for the global
microwave electronics market place including commercial and military wireless telecommunications.
Dedicated to R&D of standard and custom design quality ferrite circulators and
isolators from 380 MHz to 23.6 GHz.
Appreciation of Their Support
Bittele Electronics is a leading turn-key PCB assembly manufacturer in the EMS
Industry offering one-stop PCB assembly
services including PCB fabrication, parts procurement and final circuit board
assembly. Expertise in DFM (Design for Manufacturing) checking for
your every order. Ideal service for PCB prototyping and low / high volume production
runs.
& Mobile App from Hittite
Hittite Microwave Corporation is pleased to announce
the release of the
Hittite's 2013 Product Selection Guide summarizing over 1100 products
including 22 new products. New for this publication are GaN PAs, an I/Q downconverter
and sub-harmonic MMIC mixers. The Selection Guide is organized by RF & microwave,
analog & mixed signal, clocks & timing and LO frequency generation IC sections
along with modules and instrumentation. Hittite's 2013 Off-the-Shelf Newsletter
includes 17 new product highlights & articles and company news organized by
market application.
Radio & Television News ran a
two-part article on the state of the art of computers in the late 1950s. It had
only been since ENIAC's (Electronic Numerical Integrator And Computer)
debut in 1946 at Massachusetts Institute of Technology (MIT) that the
public (or science community for that matter) was getting used to regularly
hearing about computers in the news. By 1957 there were many companies popping up
with
electronic computer offerings. Originally the exclusive purview
of university research labs and defense installations, the size and cost of computers
was moving into the realm of affordability by corporations that used them for accounting
and bookkeeping, and in some cases even rented idle time to outside users. Desktop
PCs and notebook computers were still the realm of crazy dreamers.
The Remington Rand
"Univac" (UNIVersal Automatic Computer) computer was delivered on
March 31, 1951. Its main memory consisted of liquid mercury delay lines arranged
in 1000 words of 12 alphanumeric characters each. A Univac famously calculated the
first presidential race forecast - Eisenhower vs. Stevenson - and was correct! This
1957 report mentions how "giant electronic computers no longer rank as laboratory
curiosities or frightening science-fiction robots." The Unisys company is today's
descendant of Remington Rand.
Long-Time Support!
Coupling Matrix Synthesis
(CMS) tool facilitates synthesis of N+2 coupling matrices for Chebyshev
bandpass filtering functions, with arbitrary finite-position transmission zeroes.
Filter orders up to 12, arbitrary placement of complex transmission zeroes, S-parameter
file (s2p) generation, dvanced graph and marker functions, much more.
Information warfare is emerging as the new war fighting paradigm of the U.S.
and many of its allies. This book is the first in the field to address communication
electronic warfare (EW) systems in the context of
information warfare. Authored by a recognized leading authority, the book includes
a unique formulation of EW system performance and presents results of system simulations
that have not appeared previously in any related literature. Essential reading for
EW engineers and researchers working in defense, aerospace, and
military capacities, the book explores the properties of information, the properties
of information communication means, information theory, and EW system architectures.
Here is
the latest set of job-related articles
referenced from the IEEE's The Institute newsletter that seem to be worthwhile...
IMHO, anyway.
-
When Business Conduct
Might Be Business
Misconduct
-
For Consultants, Social
Media 101
-
Vehicular Technology
Conference Focuses on
Wireless
-
Peter Johnson: From Janitor
to NASA Engineer
Air Traffic Control
The Civil Aeronautics Administration
(CAA), born in 1940 and now known as the Federal Aviation Administration
(since 1958), was established originally to regulate the burgeoning
commercial airline and cargo transport air traffic as well as the private aviation
activity. According to an FAA document, on April 3, 1947, CAA controllers began
in-service evaluations of the ground approach control (GCA) radar system
at Washington National and Chicago Municipal airports. It was commissioned for officially
use by the CAA on January 7, 1952, at Washington National Airport. This story from
a 1957 edition of Radio & Television News reports on the system upgrade
to
long-range radars that would permit, eventually, continuous coverage
across the entire USA.
at IMS2013 Show, Denver, CO
Empower
RF Systems invites you to visit them at their booth (#206) at the
EMC2013 show in Denver, Colorado,
from August 5 - 9.
Purchases Nova Microwave
Electro Technik Industries, Inc. of Clearwater,
Florida has purchased Nova Microwave of Morgan Hill, California. Nova Microwave
designs and manufactures RF/Microwave isolators and circulators for both commercial
and defense applications. With almost 20 years of experience in the microwave
business, Nova Microwave offers a number of different styles from drop-ins to surface
mounts. The frequency ranges from 380 MHz to 23.6 GHz with average
power ratings from 2 to 250 watts.
for Their Support
Fotofab is a supplier of custom-made thin metal parts. Chemical etching, metal
stamping, RF shielding, or any custom
part made out of metal. RF/EMI shielding, metal stamping, lead frames, filter screens.
Samples are available.
"de Forest has said in many newspapers and
over his signature that it would be possible to transmit the human voice across
the Atlantic before many years. Based on these absurd and deliberately misleading
statements, the misguided public... has been persuaded to purchase stock in his
company." - U.S. District Attorney, prosecuting Lee de Forest for fraud in 1913.
Crossword for July 14, 2013
Take a break and work this week's microwave 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.
Appreciation of their Support
Orbel Corp. is the leading designer and manufacturer of
RF Shielding
and EMI/RFI Isolation Products for printed circuit boards and electronic enclosures.
Orbel also specializes in thin gauge
Photo Etched Metal Parts and
Precision
Metal Stampings made from a wide variety of material options.
Erie International Airport
On
July 3, 2013, the EAA AirVenture Museum flew a
Ford Trimotor (aka "Tin Goose") into Erie International
Airport, and offered rides for $75 per seat. Normally, rides in vintage aircraft
cost much more than $75, so Melanie and I jumped at the chance. We got about a 16-minute
ride out to Presque Isle and around Presque Isle Bay. The experience of flying in
an aircraft with three radial engines was definitely worth the investment, especially
since it was a cool day, winds were light, and the visibility was unlimited with
a little haze. Even with finely balanced propellers and 9-cylinder radial engines,
the vibration level was very notable. Unless you are an airplane lover who responds
to such stimulation the way a newborn baby responds to its mother's heartbeat, I
can understand how hours-long flights might have been a bit wearisome...
Amplifiers Deliver up to 25 W
Hittite Microwave announced four new GaN MMIC
power amplifier products which offer significant performance, size and durability
advantages for communications, test instrumentation and radar systems operating
in the 2 to 20 GHz frequency range. The
HMC1086F10 is a 25 W GaN MMIC PA which operates at 2-6 GHz.
It typically provides 23 dB of small signal gain, +44 dBm saturated output
power, and delivers +46 dBm output IP3 at +33 dBm. The
HMC1087F10 is an 8 W GaN PA which operates at 2-20 GHz.
It typically provides 11 dB of small signal gain, +39 dBm of saturated output
power, and +43 dBm output IP3 at +28 dBm.
Keep a Job in 2013
![Tip on How to Find and/or Keep a Job in [July] 2013 - RF Cafe](images/job-hunting-tips.jpg)
Here are a few useful job hunting (and keeping)
tips from around the web.
-
2013 Engineering Jobs
Outlook
-
Is a 2-Page Resume
Ever OK?
-
How to Achieve Likeability
-
Can I Turn Down an Offer
I've Already Accepted?
-
How to Think Like a Leader,
by Jack Welsh
-
Ignore These 10 Outdated
Job-Search Advice Tips
-
5 Ways to Better Position
Yourself For a Pay Raise
-
What to Include in a
Cover Letter
VCO w/Extremely Low Ø-Noise
Z-Communications announces a new dielectric resonator
VCO model DRO12600A
for the test and measurement market. The DRO12600A is designed to cover 12600 MHz
with a tuning voltage range of 0 to 12 Vdc. This unmatched VCO has been optimized
to feature extremely low phase noise of -102 dBc/Hz @ 10 kHz offset while
operating off a 5 Vdc supply and typically drawing only 23 mA of current.
The low noise DRO12600A is designed to deliver a typical output power of 0±3 dBm
into a 50 Ω load.
Wireless & Defense Products
Haven't looked over out broad range of cavity,
ceramic, LC, and SAW filters, duplexers, triplexers, and
multiband combiners
recently? If you do, you'll find new models and a greater range of models than ever
before.
3 New Nobel Prize Winners
Anyone visiting RF Cafe (other than
by accident) almost certainly knows of Drs. Bardeen, Brattain and Shockley
fame for their transistor invention while jointly working at the Bell Telephone
Laboratories. The trio shared
The Nobel Prize in Physics in 1956. Bell was so proud of their
employees' efforts that they ran full page advertisements to boast of the accomplishment.
This one appeared in the February 1957 edition of Radio & Television News. Alas,
Ma Bell's moment of glory was a bit diminished by needing to add a footnote admitting
that Drs. Bardeen and Shockley no longer work there.
Engineering Jobs Openings
Engility
has announced the following fully-funded engineering positions in Camarillo, California.
- FMS Systems Engineer Lead
- RF/Microwave System
Architecture Engineer
- Engineer
Launched in July 2012 as a spin-off company of L-3 Communications, Engility possesses
more than 40 years of combined experience across nearly 70 different legacy companies.
in Wireless Taxes
When you read or hear news stories about the
total amount of taxes you pay, the number can seem unreasonably high until you account
for payroll (federal, state, local), standard point-of-sale (state, local), special
PoS (cigarette, gas, appliance disposal), utilities (electric, phone, heating fuel,
water), and multitudinous other hidden taxes. Per CNN today: "Your wireless carrier
isn't the only one pocketing money when you pay your
cell phone bill.
Local, state and federal governments, 911 systems and even school districts tack
on taxes and surcharges to your wireless bill that end up costing American cell
phone customers an extra 17.2%, on average, according to the Tax Foundation. That's
up from 16.3% fifteen months ago."
for Continued Support!
At VidaRF, the phrase "Providing Simple Solutions for Complex Connections" is
more than just a slogan – it's a mindset, a mission, and a driving force behind
everything we do. Our pledge is to design and distribute high performance, cost
effective RF and Microwave products
to fit each customer's unique applications. Attenuators, cable assemblies, connectors &
adapters, isolators, circulators, couplers, and power dividers are among our offerings.
Introduction to Radar Systems, by Merrill Skolnik. Since the publication
of the second edition of "Introduction to Radar Systems," there has been continual
development of new radar capabilities and continual improvements to the technology
and practice of radar. This growth has necessitated the addition and updating of
the following topics for the third edition: digital technology, automatic detection
and tracking, Doppler technology,
airborne radar,
and target recognition. The topic coverage is one of the great strengths of the
text. In addition to a thorough revision of topics, and deletion of obsolete material,
the author has added end-of-chapter problems to enhance the "teachability" of this
classic book in the classroom, as well as for self-study for practicing engineers.
Statistics for June 2013
I rarely look at website server statistics
for RFCafe.com
because my focus is on providing useful content and not trying to devise clever
schemes to trick or coerce visitors into clicking on ads. Adding significant material
on a daily basis since 1999 has resulted in prominent page rankings and search engine
positions for many relevent keywords and phrases. My philosophy is to provide you
with as little annoyance as possible while also creating a venue where companies
will pay me to present their goods and services. An unwillingness to curb my content
and comments to satisfy some peoples' ideas of correctness has undoubtedly cost
me visitors and advertisers, but c'est la vie. I am always a bit dubious about what
data are included in the numbers and charts presented by many websites, so I never
make absolute claims for any statistic. A popular tactic is to include numbers that
include every item requested from the server with each page view, which includes
images and any files loaded into an inline frame. Here are a few charts for June
2013, in case you care. Notable points are the pronounced dips in page views during
weekends and for some odd reason, the top search phrase for June was "density of
sand."
UART Offers Exceptional Range
The Linx Technologies 250 Series
RF transceiver module is designed for reliable bi-directional
transfer of digital data over distances of up to 4 miles. Operating in the
902-928 MHz ISM frequency band, the module is capable of generating +23.5 dBm
into a 50-Ω load and achieves a typical sensitivity of –105 dBm. This
high output power gives the module remarkable range and also helps overcome noisy
environments at shorter ranges. The module implements a Frequency Hopping SS protocol
with a UART serial interface that can be connected directly to microcontrollers,
RS-232, RS-485 converters or USB adaptors.
Checking (L, C, R)
When this article on component (resistor,
capacitor, and inductor) measurement was written, readily available, inexpensive
multimeters were not in existence. For about $20 you can now buy a brand new handheld
DMM that will make very accurate resistance measurements and reasonably good capacitance
measurements at frequencies up to a few MHz, where lead inductance starts to be
significant (test frequency is usually only a few kHz). Finding an
affordable, accurate inductance meter is another story. Cheap LCR meters can be
purchased on eBay, but don't be surprised if the quality is not very good. The most
accurate
component measurement method uses a frequency in the realm of
actual operation, and this article presents methods that will allow you do do just
that by using typical bench top instruments.
2.0 GHz Digital Phase Shifter
PMI Model No.
PS-500M2G-8B-SFF is a Stare-of-the-Art, 8-Bit Digitally Controlled
Phase Shifter that operates over the 500 MHz to 2.0 GHz frequency range.
This model has a typical insertion loss of 10dB and offers 360 degrees
of phase shift via 8-Bit TTL control. The phase shift error is less than ±10 degrees
and the amplitude error is less than ±1 dB. The switching speed is 500 nsec
maximum.
Started July 8, 2013
Please take a moment and vote
in this poll. No sign-in-required. Results are displayed automatically. Thanks!
See current.
Commemorates Roswell
Today's Google Doodle is actually a goofy video game that celebrates the
whole Roswell
UFO/alien thing. I would like the 10 minutes of my life back that I spent playing
it through to the end. Per
Wikipedia,
"On July 8, 1947, the Roswell Army Air Field public information officer Walter Haut,
issued a press release stating that personnel from the field's 509th Operations
Group had recovered a 'flying disk', which had crashed on a ranch near Roswell."
The truth is out there.
"If you have any trouble sounding condescending,
find a Unix user to show you how it's done." - Scott Adams, Dilbert creator. I can
remember when that was true, but I'm not so sure it is anymore. A contemporary example
might be to find an Apple product user.
Super-low-noise-figure receivers are absolutely
essential in
radio astronomy work. The need has driven major advances in the
state of the art of cryogenically cooled front ends with noise temperatures near
absolute zero. Antenna technology has also benefitted from radio astronomy due to
the need for precision steering and narrow beam widths. Phased arrays (aka
interferometers) for interstellar targets requires that element spacing be
large enough to require separate antennas as the elements, which creates a very
large effective aperture, hence greater angular resolution. Networks located continents
apart are synchronized with the use of atomic clocks to allow signal time of arrival
and therefore phase to be accurately measured. This story gives some of the early
efforts.
for Long-Time Support!
NoiseWave is an international supplier of noise sources and test equipment. Noise
is their focus, and only business, so they can help yours. NoiseWave provides their
customers with high quality standard
and custom noise test solutions to meet commercial and military wireless
applications.
Appreciation of their Support
Amplical was founded by Engineers for Engineers. Amplical is a leading supplier
of quality RF microwave components. Utilizing the latest in RF Microwave technology,
Amplical focuses on premium quality amplifiers and attenuators at affordable prices. Amplifiers are
tuned for exceptional amplitude flatness and our attenuators are designed for precision
and the utmost in accuracy. Products are typically available from stock. GaAs technology.
for July 7, 2013
Each week I create a new custom crossword puzzle
that uses only personally selected words pertaining to engineering, science, mathematics,
aeronautics, metrology, chemistry, tech companies and leaders, etc. There are no
words or clues for movie star names, sports heroes, or obscure villages in Timbuktu.
Advertisement
For a given semiconductor compound, the maximum
operational speed of a transistor is governed pretty much by its gate thickness.
Capacitance and impurities along with lithography precision and accuracy are the
culprits. Shrinking gate sizes and growing crystals with greater purity has driven
operational speeds upward significantly over the years. An equivalent set of issues
plagued vacuum tube development a century ago. The physical spacing of grid elements
wrt each other as well as to the cathode and plate placed an upper limit on amplification
bandwidth. As always, judicious study of the underlying causes led to the development
of new designs that, along with improved manufacturing techniques, overcame existing
barriers and, also as always, exposed yet a new set of limiting criteria for conquering.
That's the way of science and engineering. This advertisement from a 1954 edition
of Radio & Television News featured breakthrough development by
Western Electric of the 436A vacuum tube for tripling the number
of voice calls that could be sent over a single coaxial transmission line.
Has Bi-Directional Digital Data
Designed for dependable bi-directional transfer
of digital data, the
25 Series RF transceiver module is capable of transmitting over
distances of up to 1 mile (1.6 km) line of sight. Operating in the 902
to 928 MHz ISM (Industrial Scientific and Medical) frequency band, the module
is capable of generating +13 dBm into a 50 ohm load and achieves an outstanding
typical sensitivity of –105 dBm. The 25 Series module implements a Frequency
Hopping Spread Spectrum (FHSS) protocol along with networking and assured delivery
features.
Here is a nice quiz on
calculating total equivalent capacitance for circuits containing
various combination of series, parallel, and series-parallel connections. To help
in calculation, all of the individual capacitor values are the same. Many of them
you can probably solve in your head, especially if you mentally rearrange the circuit
into a more readily recognizable configuration. For instance, circuit #1 can be
redrawn having two parallel branches across the source. One branch has just a single
capacitor while the other has two parallel capacitors in series with one capacitor.
The equation is then C + (2C2/3C)
= C + 2/3C = 5/3C. For C = 6 pF, Ctotal = 5/3*6 pF = 10 pF.
"Priming the Relays"
Tales from the Cube is a regular
feature run by EDN, in which readers tell tales of interesting experiences in their
engineering careers. This particular story is very interesting and highlights why
you should never accept that a solution to a problem has been found until you fully
understand the initial cause. What's really scary is that evidently this product
and its 'cure' are probably still doing active service in airplanes around the globe.
It is hard to believe that a QA department would sign off on such a deal.
Available for European Market
The new
868 MHz NT Series RF transceiver module from Linx makes it
simple to send and receive digital data in the 863 to 870 MHz band. The module
offers the option of UART or True Transparency™ interfaces which lets the user create
a wireless wire for use with nonstandard data rates, custom protocols, or encodings
such as PWM and Manchester. The module features best-in-class receive sensitivity
(up to -113 dBm) and low power consumption (only 19.2 mA
in receive mode and 16mA in transmit mode at 0 dBm).
of Its HF Design Software
AWR has released Version 10.07, the latest update
to its V10 suite of high-frequency design software tools, inclusive of
Microwave Office®/Analog Office® circuit design software and Visual System Simulator™
system design software, as well AXIEM® 3D planar EM software and Analyst™ 3D finite
element method EM software. Hundreds of enhancements, many of them user-requested
features, have been made to this latest release, including significant additions
to AWR's unique and powerful EM technologies.
0.7-4.2 GHz Broadband Amp
Electro-Photonics LLC announces the availability
of a wideband power amplifier operating from 0.7 - 4.2 GHz. Their new
EPA-0742P1-SF uses the latest GaN technology to achieve a gain
of 46 dB and an exceptional gain flatness of ±1 dB. This amplifier
provides 30 dBm output power in a very small package (6.49 x 2.87 x 1.89 inches).
for Continued Support!
Dow-Key Microwave is the world's largest manufacturer of
electro-mechanical RF switches.
They are AS9100 / ISO-9001 certified and committed to providing unparalleled customer
service, competitive pricing, on-time delivery and switch products that are distinguished
by quality and reliability. Dow-Key offers the largest RF switch product line in
the world with over 10,000 unique configurations.
Winner Niger S. !!!
Congratulations to RF Cafe visitor Niger S.,
of Herndon, Virginia, for winning the
June Book Drawing.
Nigel selected
Handbook of RF, Microwave, and Millimeter-Wave Components.
Each month I select someone to receive a free book from those provided by Artech
House or Cambridge University Press. They are often books I have used to create
quizzes. How to enter? Either
buy one of my inexpensive
software offerings or send me an e-mail.
That Amplifies
Hmmmm... I never really thought about the
transistor as a crystal amplifier, but in fact it was fabricated
from a crystal of germanium with two 'cat whisker' wires pressing on its surface.
Before the transistor was the simple rectifier made of a crystal of selenium or
even carborundum with a point contact. Those were used for turning AC into DC and
for detecting radio wave modulation envelopes. For a really good synopsis of the
early development path of semiconductors, read this story from a 1968 edition of
Popular Electronics that commemorated the 20th anniversary of Bardeen, Shockley,
and Brattain announcing their transistor. Having been written much closer to the
days of discovery, the story has not been filtered through as many writers' points
of view, and contains some information I'll bet you have never read before. E.g.,
did you know that semiconductor dopants were originally referred to as adulterants?
Did you know that Shockley's early research was on field effect devices and, if
successful, would had made FETs the first forms of transistors rather than...
Conventional Fuel Cars
In a recent IEEE Spectrum story titled, "Unclean at Any Speed," Ozzie Zehner contends based on research
that electric cars don't solve the automobile's environmental problems. After factoring
in the big picture from beginning to end of production of the vehicle, its battery
pack, and the charger, the inefficiencies of electric power production and distribution,
and battery change-out and disposal, even reaching break-even is questionable. Mr.
Zehner, BTW, is a convert from the
EV church
of true believers, having even built his own e-car decades ago when doing so
would more likely elicit strange looks than entranced gazes of fawning approval.
He changed sides after extensive research suggested maybe the numbers were being
manipulated in order to advance an agenda. The impetus to "go green" with autos
has more to do with a need to feel good about one's self than reality. That said,
I'd gratefully accept a donation of a
Tesla Roadster
any day.
Handbook of Reflector Antennas and Feed Systems Volume 3: Applications
of Reflectors, by Sudhakar Rao, Lotfollah Shafai, and Satish K. Sharma.
This is the first truly comprehensive and most up-to-date handbook available on
modern reflector antennas and feed sources for diversified space and ground applications.
There has never been such an all-encompassing reflector handbook in print, and no
currently available title offers coverage of such recent research developments.
The Handbook consists of three volumes. Volume 3 focuses on the range of reflector
antenna applications, including space, terrestrial, and radar. This book covers
recent developments of reflector antennas used for satellite communications, terrestrial
communications, and remote sensing applications.
Cellphone Metadata Tracking
Are you one of those people who say you don't
mind the government collecting data on you because you've done nothing wrong? This
might change your mind. German politician
Malte Spitz sued Deutsche Telekom for 6 months of
metadata that they collected from his cellphone usage. A programmer
used it to create a real-time, animated map of how the reporter's movements were
tracked within and between cities, how long he was at each location, and with whom
he was communicating. His phone-based Internet surfing was logged. Anyone in Spitz's
immediate vicinity (supporters, business contacts, etc.) would also
be known. That was waaaay back in 2009; what do you think Big Bro knows by now?
Are you absolutely sure your history will never be misinterpreted or - indulge the
conspiracy theorist in me - manipulated at the government's convenience?
from Electro-Photonics
RF Cafe advertiser
Electro-Photonics offers a free TRL calculator. "TRL (Thru,
Reflect, Line) remains one of the most popular alternative calibration methods
for measuring non-coaxial devices to the traditional short, open, load, and thru
(SOLT), two-port error correction calibration method.
TRL calibration
is based upon an 8-term error model and uses three standards - thru connection,
high reflectivity termination, and a section of uniform line (λ/4 longer than
the thru line at the center frequency). The electrical length of the line
is determined during the calibration and does not need to be known. The characteristic
impedance, Z0 of the delay line is the only critical parameter."
"The sleep that shuns my restless bed | Returns
to haunt my desk instead." - Frank R. Canning, July 8, 1950 Saturday Evening
Post. Can you relate to that?
Broadcasts from shortwave (SW)
station
WYFR, based in Okeechobee, Florida, ended today, June 30, 2013,
after nearly 35 years of continuous operation. Prior to the advent of the Internet,
cellphone, and WiFi services, SW radios were the only means of receiving information
in the nether regions of the earth where war and Communism denied people access
to information that might contradict the strict dictates of iron-fisted regimes.
As with so many other groundbreaking technologies of yesteryear, shortwave broadcast
stations are rapidly disappearing because costs are prohibitive. If you click on
the thumbnail above, you will see many cool photos of the
WYFR station equipment room and antenna field that included
14 transmitters
and 23 antennas directed toward various parts of the world. It's kind of
sad, but I had to laugh at this line from one article on the sign-off, "Family Radio
has been struggling ever since the world did not end as predicted in 2011."
