"Throwing the works to my bottle." Any idea
what that means? Neither did I. "You went out just like a Swedish match in a Kansas
hurricane..." Ever heard that saying? Neither had I. I never knew Swedish matches
had a reputation for easily going out. I never knew the swedes made matches. Evidently
the tech jargon in 1935 was a bit different than today. This story from QST will
introduce you to many new terms with a
fairly short read. The guy in the story looks
a lot like the Ham in the 2013 Field Day patch (sans specs).
This latest installment of EDN's
Tales from the Cube series. In it, author
Bruce Mainwaring describes his ingenious process for emergency
testing assembled and ready to ship product for a bad inductor. It involved building
an EM simulation
model for the test implement and then qualifying it with a Kappa analysis inductor.
The action saved his company significant embarrassment.
Technology for Their Support
WOKEN specializes in microwave/RF
coaxial connectors, cables, cable assemblies, microwave/RF antennas and RF accessories.
With the experienced R&D engineers & technicians, active marketing staff,
up-to-date production equipment and measuring instruments, WOKEN designs its own
RF / microwave products for meeting all kinds of requirements demanded by its customers
at communication markets.
There's an App for That
Bosch has been at the forefront in
automobile navigation
automation for many years. They developed some of the first systems for keeping
cars in lines of traffic without the driver needing to constantly apply brakes or
step on the gas (or battery) pedal. You can find lots of cool videos on their work.
This video shows a new system for automatically parking a car via a smartphone app.
I'm sure somewhere there is a group of lawyers just salivating at the prospect of
lawsuits when someone gets her legs pinned between cars in the process. Maybe it
will just be a smashed bicycle, or flattened puppy, but you know they can't wait
for an opportunity.
Microstrip Lines and Slotlines
This quiz is based on the information presented
in Microstrip Lines and Slotlines, by Ramesh Garg, Inder Bahl, and
Maurizio Bozzi. The book was graciously provided by
Artech House. As
with many books used for quizzes, this one will eventually be made available as
prize for the RF Cafe
monthly book drawing.

These quizzes are also good
fodder for selecting interview questions for applicants and for brushing up on the
basics if you are the interviewee.
SP4T Absorptive Switch
PMI Model No.
P4T-100M2G-50-T-SFF-IN is an absorptive, single pole, four throw
solid-state switch that operates over the 100 MHz to 2.0 GHz frequency
range. The insertion loss is less than 3dB and offers port to port isolation of
over 50 dB. The switching speed is 25 nsec maximum and the rise and fall
times are less than 10 nsec. The control is via four independent TTL lines
with Logic "0" being the low-loss state and Logic "1" being the isolation state.
This switch operates on ±5 VDC
for Used Test Equipment
Mr. Richard
Barker, of Kitmondo, wrote to request a listing on my
Test Equipment
(new & used) vendor resource page. Kitmondo is based in the UK and is "an
online marketplace where buyers and sellers of used business and industrial equipment
can find each other and trade safely." They currently have many pieces of
TE and
individual RF components like amplifiers and attenuators.
Crowdfunding
is a scheme whereby inventors
and other types of startup individuals and groups pitch their plan to the public
and solicit payment of funds with the promise of certain goods or services when
and if the monetary goal is met or exceeded. If, for instance, I wanted to develop
new RF system planning software and needed, say, $100,000 to produce a beta version,
I might promise $50 donors ('investors') a specially designed T-shirt, $100 donors
an early beta for evaluation and discount on first release, and $500 donors a full
release version.
Inc magazine had as their June edition
theme leadership. If nothing else, the collection of articles proved the old adage
about opinions being like ***holes - everybody has one. There were some worthwhile
tidbits, though, like this quote from Captcha co-founder
Luis Von Ahn: "Competition among investors is good. If you are
talking to one big VC and wind up talking to another, they will find out. How much
that matters is insane."
Xcvr to Optimize RF
The new
DP1203 Series radio-only RF transceiver module is designed for
the wireless transmission of digital data at data rates of up to 152.3 kbps.
Operating in the 433, 868 and 915 MHz license-free ISM frequency bands, this
module series is ideal for applications that require full-control of the radio channels
and configuration, without having to go through the effort and expense of a discrete
RF design. The module has a maximum output power of +15 dBm and a receiver
sensitivity of –111 dBm. This gives the module a typical line of sight range
of 2 to 3 miles at the maximum output power with typical monopole whip antennas,
depending on frequency.
for June 14, 2013
Take a break and let this week's engineering-themed
crossword puzzle be a Father's Day present to yourself. 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.
Data from Tech Companies
Here is an interesting chart from Reuters
that shows which countries have the
highest rate of collecting data from tech companies. Google, Microsoft,
Skype, and Twitter are evidently the top suppliers of personal data. I'm guessing
the U.S. is at the top at least partially because the tech companies are based in
the U.S. and therefore the
FBI, NSA, IRS, DHS, and other 3-letter agencies are able to exert
the most influence. Of course what is not shown are countries that make no pretense
of granting citizens a right of personal privacy such as Russia, China, Saudi Arabia,
Venezuela, and other Communist regimes. Our government exploits a populace that
actually expects privacy because the Constitution mandates it. They don't need to
heed no stinking Constitution.
Transformer Tutorial
The word 'transformer' in the title for this
article does not refer to a mutual inductance transformer, but an impedance transformer
for
matching transmission lines to antennas (or anything else for
that matter). Author T.A. Gadwa gives examples of impedance-matching circuits
both for when the antenna impedance is lower than the characteristic impedance of
the transmission line and when the antenna impedance is higher than that of the
feed line. "L," "pi," and a couple other circuit configurations are covered.
Capacitors & Dopey Design
In the latest adventure of
Sherlock Ohms, Mr. Frank Karkota tells of his experience with
a used digital satellite receiver for reception of free-to-air (FTA)
programs. "The receiver worked great, and I mapped hundreds of television and radio
stations on the various satellites. Later, some of the stations disappeared. Then,
more started disappearing, until I couldn't find any stations. Since my analog receiver
still worked, I concluded that the digital receiver had failed. I opened the receiver
and found that in one corner was the RF section, another corner had the digital
section, and the other side housed the power supply..."
Solutions for Connected Home
Skyworks Solutions today announced that it is
partnering with SMC Networks, a leading customer premise equipment manufacturer
for multi-service operators (MSOs), to develop wireless connectivity solutions for
security, monitoring and automation (SMA) applications in the emerging connected
home market. SMC is utilizing Skyworks' wireless networking and
ZigBee®
front-end solutions for security sensors, smoke alarms, motion detectors and touch
pads. “SMC is joining forces with Skyworks to deliver innovative solutions for the
connected home,” said Max Brogi, vice president of product management at SMC Networks.
Korea & Japan Agendas
AWR, the innovation leader in high-frequency EDA
software, has finalized the agendas and opened registration for the summer
AWR Design Forums (ADF)
2013 being held in
Seoul,
Korea on Monday, July 8th and
Tokyo,
Japan on Friday, July 12th. The ADF is a free and open event where designers
of microwave and RF circuits and systems such as MMICs, RF PCBs, and LTE communication
systems can network, share useful information and resources pertinent to high-frequency
design, and collaborate on industry issues and trends.
If terms like 'magnetostriction,' mu-metal,'
and 'D-ring' arouse your technostimulus receptors, then this
quiz on magnetics should be just what you've been waiting for.
It appeared in a 1962 edition of Popular electronics, but the principles therein
have not changed since then. I must admit that I had never given thought to the
orientation in which bar magnets should be stored when in close proximity to each
other.
High-Frequency Integrated Circuits,
by Rosin Voinigescu. A transistor-level, design-intensive overview of high speed
and high frequency monolithic integrated circuits for wireless and broadband systems
from 2 GHz to 200 GHz, this comprehensive text covers high-speed, RF,
mm-wave, and optical fibre circuits using nanoscale CMOS, SiGe BiCMOS, and III-V
technologies. Step-by-step design methodologies, end-of chapter problems, and practical
simulation and design projects are provided, making this an ideal resource for senior
undergraduate and graduate courses in circuit design. With an emphasis on device-circuit
topology interaction and optimization, it gives circuit designers and students alike
an in-depth understanding of device structures and process limitations affecting
circuit performance. This book is the subject to
RF Cafe Quiz #49.
Microwave for Their Support
Wenteq provides a wide range of high quality
RF and microwave products
with quick delivery time at very competitive low prices. Their products include
coaxial connectors and adapters, circulators, isolators, low noise amplifiers, power
amplifiers, broadband amplifiers, terminations and more, covering the frequency
range of 100 MHz to 110 GHz.
Started June 11, 2013
Please take a moment and vote
in this poll. No sign-in-required. Results are displayed automatically. Thanks!
See current.
I/Q Up & Downconverters
Hittite Microwave has launched several new, highly
integrated I/Q upconverter and downconverter products which cover the licensed 38 GHz
and 42 GHz bands in microwave radios for cellular backhaul radio links. The
HMC6787ALC5A and the
HMC6146BLC5A are GaAs MMIC I/Q variable gain upconverters which
form a competitive and cost-effective microwave radio transmitter solution which
has been designed to meet or exceed all of the performance criteria required for
modern high capacity QAM microwave radios. The
HMC6787ALC5A operates from 37 to 40 GHz and provides a small
signal conversion gain of 10 dB with 17 dBc of sideband rejection, and
13 dB of gain control.
of Simple Math
Many people were reluctant to approach the
theoretical aspect of electronics as it applied to circuit design and analysis,
QST (the ARRL's monthly publication) included equations and explanations
in many of their project building articles. Occasionally, an article was published
that dealt specifically with how to use simple mathematics for
electronics calculations. In the July 1944 edition is the third
installation of at least a four-part tutorial that covers resistance and reactance,
amplifier biasing oscillators, feedback circuits, etc. I do not have Part I
from the May 1944 edition or Part IV from the August 1944 edition, but if you
want to send me those editions, I'll be glad to scan and post them.
NSA's PRISM program
has been in the headlines lately because of its omnipotent, omnipresent purpose
of recording every possible form of electronic communication into, out of, and within
the U.S. Per the Constitution's
4th Amendment: "The right of the people to be secure in their
persons, houses, papers, and effects, against unreasonable searches and seizures,
shall not be violated, and no Warrants shall issue, but upon probable cause, supported
by Oath or affirmation, and particularly describing the place to be searched, and
the persons or things to be seized." What part of that is difficult to understand?
If such blatant disregard for the law is deemed necessary to protect the country,
why didn't it prevent the Benghazi, Ft. Hood, and Boston Marathon terrorist attacks?
The government had ample info on record about all three but ignored it for political
correctness reasons. Surely they knew the Benghazi attack was not due to "an offensive
video" prior to selling the lie to the public. Yet, when it comes to targeting specific
political groups, the IRS seems to know all it needs to manipulate national elections.
Think you're safe from PRISM,
et al, since you've done nothing wrong? Watch who you offend - if not today then
tomorrow when control changes hands.
Distribution Agreement
Linx Technologies, a developer and manufacturer
of wireless products such as radio frequency
RF modules, announces
a distribution agreement with
DComponents Corporation, a global electronics distributor with
a strong presence worldwide that provides catalog distribution catering to design
engineers, engineering students, research labs and Original Equipment Manufacturers.
DComponents Corporation will sell and support Linx modules, connectors and
Antenna
Factor antennas.
World-Wide DX
Here is a quick course on how to point antennas
for over-the-horizon (DX) reception, and, if you also happen to have
a license to transmit, for broadcasting. It covers how to determine the shortest
straight-line path by stretching a string around a globe
(remember those spherical maps that used to be a mainstay of every household and
schoolroom?) and using a protractor (a what?) to get the angle.
Author Edward Noll uses a simple 1/2-wave dipole antenna radiation pattern as an
example of how directivity is affected by frequency (relative to the fundamental).
Electron Microscope
Optical magnification is only useful to the
point where resolution is limited by the wavelength of light representing the object
under observation. Astronomer William Dawes first provided a means of quantification
based on an ability to visually resolve closely spaced stars. Known as the Dawes
Limit, a value of 4.56/D arc seconds was empirically determined (D is aperture of
instrument in inches). A theoretical upper limit to magnification of any optical
system with perfect optics is around 2,000. The
electron microscope removed that resolving limit by shooting a
stream of electrons with radii much less than the wavelength of visible light, and
measuring its reflection. Images are necessarily in 'false color' because we cannot
perceive the real wavelength/color of the surface revealed by the electron beam.
Winner Bogdan V. !!!
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. This month's winner,
Bogdan V., selected Introduction to
RF Design Using EM Simulators (Artech House),
by Hiroaki and Yoshie Kogure, and James Rautio. "Richly illustrated, this resource
provides novice engineers and engineering students with a solid introduction to
the use of EM simulation in RF design. This book describes exactly how microwave
and high-speed digital circuits operate, offering practitioners clear troubleshooting
guidance for their work with these circuits. DVD is included."
"That's one of the reasons we can't sell a
telecom switch in most countries, for instance." -
Rob Enderle, principal analyst at the Enderle Group, on news of
NSA's ubiquitous
PRISM spy program that coerces companies into complying with demands
for user data. (what a difference 5 years makes - video)
Crossword for June 9, 2013
Every Sunday I create an engineering-themed crossword
puzzle using a word list that I personally created and added to during over a decade
of making puzzles. All of the words are related to engineering, science, mathematics,
chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing
designers. Enjoy.
On-the-Fly Alignment Data
Pinpoint Laser Systems has introduced a new and
improved data accessory named “Pinpoint Capture™” for the popular
Laser Microgage industrial measuring and alignment system. Pinpoint
Capture™ allows operators to quickly grab measurement readings, on the fly, from
as many as four remote laser receivers to analyze the alignment and performance
of their production machinery and industrial equipment. The software is a powerful,
Windows-based application that quickly records incoming readings, displays results
and enables added control.
Calibrated noise diodes are fairly inexpensive
these days and are widely used for measuring noise figure of systems and for generating
specific signal-to-noise ratios when testing receiver performance. This article
from a 1967 edition of QST describes a method for using a
'hot resistor,' aka 'monode,' as a noise reference source. When
the temperature (T) and the resistance (R) is known, a noise power can be calculated
with a precision limited by the precision of the T and R measurements. The tungsten
filament of a pilot lamp is used as the resistor.
Unless I have just forgotten,
I never remember seeing the math term
Ff (pronounced "eff-sub-eff") prior to the
other night while reading an article on dark matter. Now that I know, I'll be sure
to use it in my writing somewhere. Highlight the following text to see what it stands
for if you don't already know. "Ff = Fudge factor"
for Their Ongoing Support
Established in 1979, Reactel is an industry leader in the design and manufacture
of RF and microwave filters,
diplexers, and sub-assemblies. They offer a line of filters covering DC-50 GHz.
The latest in CAD/CAM methods and equipment in all design and manufacturing processes
are used along with a machine shop complete using CNCs, which gives the ability
to produce long production runs quickly and economically. The testing department
is equipped with the latest in Agilent network analyzers offering quick, dependable,
and accurate measurements.
Gives Semiconductors a "Trip"
I have no idea why this quiz is titled what
it is. LSI stands for "Large Scale Integration" and is generally applied to integrated
circuits, not discrete components. The quiz's creator has come up with 17 questions,
only the first of which has anything to do with LSI circuits. The other 16 are on
topics like capacitor plate spacing,
magnetorestrictive material, and coaxial cable. I realize that
LSI attempts to minimize the number of external components necessary by absorbing
them into the IC, but I'm just not sure what that has to do with whether a submarine
can communication via SHF while submerged.
Automotive Design Wins
Skyworks Solutions today announced that an increasing number of its products
are enabling telematics and infotainment systems in the
automotive market. Telematics
is the term used to describe the integrated use of computers and electronic technology
in automobiles for wireless communication applications such as cell phones, the
Internet and GPS receivers. Skyworks' industry-leading SOI switching technology
is already being utilized by global car manufacturers for seamless low noise and
broadband handoffs between audio, Blu-ray/DVD, navigation, cell phone and vehicle
security display inputs.
D-Day Advertisement
With today being the 69th anniversary (June
6, 1944) of the D-Day invasion of Normandy on the coast of France, I thought posting
this advertisement by
Hallicrafters from the July 1944 edition of QST would be apropos.
This issue of the magazine probably arrived in ARRL member's mailboxes within a
few weeks of the miraculously successful invasion of Omaha Beach, Utah Beach, Gold
Beach, Juno Beach, and Sword Beach. When you consider that in those days - and also
not so long ago for that matter - the lead time for going to the printing presses
was measured in months, the fact that this ad made the final cut for the next month's
issue (July) is noteworthy. Hence, I duly make note.
Each month the IEEE JobSite sends out an e-mail
with a few helpful hints and stories regarding
job hunting. Even though
the stock market is soaring, employment is not, so you can probably use any help
available to find a new job - whether you are currently employed or unemployed.
-
Mastering the Art of Giving a Job Reference
-
How Veteran HR Professionals Really Feel about Job Seekers from Millennial
Generation
-
1 in 10 Young People Losing out on Jobs Because of Pics and Comments
on Social Media
LNAs at MTT-S 2013
Skyworks Solutions today
unveiled a portfolio of LNAs that provide best-in-class noise figure, a critical
component to boosting weak incoming signals for today's 4G wireless infrastructure
as well as diverse broad market systems including GPS, broadband, military and satellite
communications. OEMs can now leverage a single Skyworks LNA to address all
cellular, ISM and military bands, enabling unconditional stability and simple band
specific external matching across a wide voltage range.
(Nixie) DCU
The mere sight of a
Nixie tube evokes passion and nostalgia in the hearts and minds
of vintage electronics aficionados. For the uninitiated, Nixie tubes were one of
the most successful early numeric display formats. They had wire filaments shaped
in the form of numerals 0 through 9, stacked front-to-back inside a vacuum tube
enclosure. Rather than the filament (wire) doing the glowing, the neon
gas (plus traces of others) fluoresces (glows) in the
vicinity of the wire. 7-segment LED displays had not yet hit the commercial market
when this story was published in 1970, so even though the numeric display uses vacuum
tubes (Nixie) the power supply, counter, and display driver circuits
use semiconductors rather than vacuum tubes.
Design of CMOS Operational Amplifiers, by Rasoul Dehghani.
CMOS op amps are one of the most important building blocks in many of today s integrated
circuits. This cutting-edge volume provides you with an analytical method for designing
CMOS Op Amp circuits, placing emphasis on the practical aspects of the design process.
This unique book takes an in-depth look at CMOS differential amplifiers, explaining
how they are the main part of all Op Amps. Complete chapters dedicated to the critical
issues of CMOS output stages, fully differential Op Amps, and CMOS reference generators.
PA Modules at IMS 2013
NuWaves Engineering is exhibiting its high performance,
miniaturized RF products and is also introducing and demonstrating the latest product
entry to the
NuPower™ product line of small, lightweight, and power-efficient
RF PA modules – an S- & C-band power amplifier – at the 2013 IMS hosted by the
MTT-S. The NuPower™ S- & C-band PA joins a growing line of high-performance
RF PA modules that cover VHF, UHF, L-band, S-band, and C-band frequencies in miniature
and ruggedized packages as small as 1.3 cubic inches. The PA accepts delivers at
least 15 watts of saturated power across 2500-6000 MHz.
Headlines are filled every day with new, radical
applications for the rapidly advancing 3D printer phenomenon.
3D-printed prototypes for developmental models have been around for a few years
now, but the paradigm is changing to include finished products. Just as you can
send a file for a printed circuit board that you design to a vendor for rapid turn-around
fabrication, you can now ship a
3D CAD file
to companies that will print your object.
Gears, enclosures, statues,
even wearable clothing can be turned out as single or multiple components for assembly.
Last week a story appeared about a
3D-printed airway being used to save a baby's life. Available
material media and step resolution is not yet advanced enough to make a metal ball
bearing, but it will get there. The May 2013 edition of
Smithsonian magazine has a good article on the state
of the art.
to 6120 MHz VCO
Z-Communications
announces a new RoHS compliant VCO model
V950ME36-LF in the C-band. This octave tuning VCO operates at
5120 to 6120 MHz with a tuning voltage range of 0 to 22 Vdc and provides
better than 1.1:1 tuning linearity. This high performance VCO features a spectrally
clean signal of -87 dBc/Hz @ 100 kHz offset and a typical tuning sensitivity
of 51 MHz/V. The V950ME36-LF is designed to deliver 0 dBm of output power
into a 50 Ω load while operating off a 5 Vdc supply and drawing typically 22 mA
of current.
Radio Amateur
The Boy Scouts of America was formed in 1910
in conjunction with The Boy Scouts Association in the UK. Per their 2007 website
statement, "The aim of the Association is to promote the development of young people
in achieving their full physical, intellectual, social and spiritual potential,
as individuals, as responsible citizens and as members of their local, national
and international communities." Part of being a Boy Scout is earning merit badges
by performing certain community services and by demonstrating proficiency at defined
tasks. Radio proficiency is one such merit badge. In order to earn the
Radio merit badge, along with certain other projects the Boy Scout
must participate in either Amateur Radio, Broadcast Radio, or Shortwave Listening...
for Helping Deliver RF Cafe
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.
Started June 3, 2013
Please take a moment and
vote in this poll. No sign-in-required. Results are displayed automatically. Thanks!
See current.
Variable/Step Attenuator Line
Kete Microwave announces a line of
RF variable/step
attenuators that can be used to adjust the power signal level continuously or
by step within certain frequency range. They can also to adjust the test system's
power as inset attenuator. Attenuation ranges from 0 to 120 dB with step sizes
as small as 1 dB are available at frequencies up to 3 GHz. Power handling
of 2 W to 30 W, with N, SMA or BNC connectors. These parts can work at
operating
IRS Guidelines Are Out
2016 could be the first year of crippling
health
care insurance costs, but major changes begin next year. Per the Department
of the Treasury's new document, "Shared
Responsibility Payment for Not Maintaining Minimum Essential Coverage," the
'Affordable' health care act is projecting the following mandatory plans for all
people (see page 56 for examples): Single w/no dependents = $5,000,
Married w/dependents = $20,000. Those numbers are straight from the IRS document.
Your employer pays it or passes some or all of it on to you. Low income and Illegals
(both strong voting bases) will pay nothing or else get subsidies.
You cannot opt out. Remember, the IRS is in charge of collection. Redistribution
and reparations are here, folks. Whom should we who will be paying the bill thank
for this - anyone you know?
Security Training Complete
The entire RF Cafe staff (that would
be Melanie and me) are required to undergo firearms proficiency training
twice per year. We just completed the spring 2013 qualification. Included are 380,
9mm, and .38 special handguns, and a 20GA shotgun and brand spanking new 30-30 lever
action from Henry Repeating Arms. The 30-30 is like what was used to win and tame
the wild west. The first 5 rounds for both of us at 50 yds. clustered within an
6 in. diameter - sans scope.
Tech Websites
When
I make decisions on what and how to post on RF Cafe, part of my strategy is to not
do what I hate about other websites. Three annoyances are at the top of my list:
* Audio playing automatically
without my permission (I try
never to link to pages that
initiate audio automatically)
* Full-page ads with or without
a countdown timer
* Short articles being broken
into multiple pages just to
get you to click more
You will know RF Cafe is under different management the day you see any of those
things happen here.
"We rely on our early customers to identify
issues like this for us." - Fisker Automotive representative to IEEE
Spectrum's John Voelcker during demo drive when the $106k Karma
electric car put itself to sleep while recovering from a fault. Now that's bad karma.
Might Interest You
Every month I peruse our industry's leading magazines for good articles that
cover topics pertinent to they typical RF Cafe visitor. Here are a few of the latest.
-
Design Solution for
Achieving the Lowest
Possible Receiver Noise
Figure (I worked with these
two guys a while back)
- A Topsy-Turvy World
(state of defense)
-
Aerospace & Defense and
Test & Measurement
-
Crystal Oscillators – Low
Phase Noise Under Vibration
-
Identifying Emission Sources
and Propagating Structures
L networks are probably the most common types
of
impedance matching networks not just for antennas, but for a relatively
narrowband load. Determining the required values for the network is relatively simple
using well-established equations. Knowing how to use a Smith Chart makes the job
even easier. This article from a 1966 edition of QST presents the equation
approach. If you have access to the May 2013 edition of QST, there is a
complimentary article on L networks that uses the free Smith Chart cross-platform
Java software called SimSmith. If you want to do a little complex number math, try
the 1966 approach.
for T/R Switching Applications
Skyworks Solutions, Inc. has introduced a miniature
0402 PIN diode for attenuator and transmit / receive switching applications. The
SMP1302-040LF
is a small form factor, low profile, discrete surface mount technology packaged
solution that is ideal for the handset, WLAN, CATV/Satcom, land mobile radio and
infrastructure markets. This diode offers very low insertion loss, good isolation,
low inductance and fast switching in a very small package.
Crossword Puzzle
Every Sunday I create a crossword puzzle using
a word list that I personally created and added to during over a decade of making
puzzles. All of the words are related to engineering, science, mathematics, chemistry,
astronomy, etc. There are no numbnut clues about movie stars or clothing designers.
Absorptive Switch w/Decoder
Skyworks Solutions has introduced a new 0.02 –
4 GHz, high isolation, single pole four throw absorptive switch with 50 Ω
terminations and excellent isolation performance. The symmetrical
SKY13392-359LF is ideal for military communications, test and measurement and
GSM/CDMA/WDCMA/LTE cellular infrastructure applications requiring feedback, channel
and filter-bank switching where very high isolation (>50 dB) and
low loss (1 dB) are needed. The device contains integrated logic.
for Noisy Well Pump
Here is an interesting story where the FCC
issued a citation of violation for
incidental radiation due to a malfunctioning well pump. The noise
was evidently being generated by the motor and radiated from the AC power wires.
The interference was affecting local MF and HF amateur radio operation.
FCC investigators
used direction finding equipment to locate the source ('fox hunting' in Ham
terms). The owner was threatened with a $16,000 fine unless corrected immediately,
with up to $112,500 levied if he screwed around. Replacing the AC line filter did
not solve the problem, so he probably ended up replacing the entire pump. Being
in Florida where the water tables are typically near the surface, it was likely
not a submersible type pump, so the entire assembly would have had the opportunity
to radiate. Submersible pumps use brushless induction motors deep within the metal
casing lining the well hole (a nearly ideal RF shield), but depending
on the vintage of the resident's above-ground pump it could be brushed, with arcing
causing the problem.
Here are a few recent articles from our industry's
leading magazines that you might find useful.
-
Choosing Optimal Cables &
Connectors, J. Browne
- Designing MRI Coils with Aid
of Simulation, A. Bitz,
J. Felder, T. Wittig
-
Unused RF Spectrum May
Ease Wi-Fi Traffic Jams,
I. Sokol
- Manage Growing EM
Radiation Levels, J. Browne
- Input Third Order Intercept
Point for Crystal Filters (p.22)
D. Layne
-
Measuring the Thickness of
Coated Shields, K. Wyatt
for Long-Time Support
Linx Technologies'
RF
modules, remote controls, evaluation kits and master development systems
feature straightforward hardware configuration and clear documentation, making it
simple for engineers and hobbyists to integrate wireless features without the hassle
and expense of engineering RF functionality from scratch. They also offer
design services including board layout assistance, programming, certification advice
and packaging design. "Wireless Made Simple"
Engineering Crossword
Take 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.
in Appreciation of Support
Since 1985, Apex Wireless has offered consulting, engineering, and design services focusing on high-performance,
cost-optimized products that employ wireless RF transmitters, receivers, and transceivers.
To complement our RF design expertise, we work with local experts in DSP, ultra
low power design, packaging, certification, and manufacturing. Consumer, defense,
aerospace, power, transportation, industrial, sports, and other industries served.
Powered Satellite Receiver
Have you ever heard of a 'nuvistor?' It didn't
seem familiar to me right away until after I looked it up.
Nuvistors were high mu (high gain) tubes, manufactured originally
by RCA, used in sensitive receiver front ends. They came in about a dozen different
varieties. This particular NASA-136 receiver for satellite reception uses a 6CW4
triode. Per Wikipedia, "Most nuvistors are basically thimble-shaped, but somewhat
smaller than a thimble, and much smaller than conventional tubes of the day. Triodes
and a few tetrodes were made. The tube is made entirely of metal and ceramic. Making
nuvistors requires special equipment, since there is no intubation to pump gases
out of the envelope. Instead, the entire structure is assembled, inserted into its
metal envelope, sealed...
Many times I have extolled the high quality
of QST authors' knowledge and writing skills.
H. Ward Silver writes the "Hands-On Radio" column which usually features circuit and system
design and theory topics. It often includes, gasp, mathematics. His July 2013 article
is titled "Phasors, Part One." It promises to be a good series. The last paragraph
says, "There is a final way to describe the signal - the exponential form in which
it is represented as V ejΘ. This form comes from the mathematics
behind Euler's equation in which the
coordinates of our points are miraculously shown to be equivalent to ejΘ=cosΘ
+j sinΘ. The serious and beautiful math behind this equation lies at
the heart of much electrical engineering and leads to the jaw-dropping Euler's identity:
ejπ
= -1 which unites the two most widely used transcendental number (e and
π), imaginary
numbers (j), negation and unity. Not bad for a moving point in a simple circle,
huh?" Beautiful. After reading it Melanie asked why my eyes were suddenly red. "Allergies,"
I explained.
Digital Control 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.
Polarity SMA Connectors
Linx Technologies' new low-cost gold plated connectors
are now available from Linx, adding new options to our already diverse connector
line. The gold jacks are available in
SMA and
Reverse Polarity SMA styles in straight or right-angle versions.
In addition, the 50-ohm connectors are available as PCB mount or surface mount components
offering a variety of mounting options for your design.
on Your Wrist
By the time you read this it will probably
be too late to be an original owner of this very limited edition 'Codebreaker' watch, made by the prestigious UK Bremont
Watch Company. Each Codebreaker watch will incorporate a piece of pine wood from
the iconic Hut 6 and numbers from some rare, original punch cards used in wartime
machines that carried out rapid analysis of encrypted message systems
to assist the Codebreakers. Each watch will also have incorporated into its
rotor, material from an original Enigma machine
rotor. Speaking of
Bletchley
Park news, the WWII era
Electronic
Delay Storage Automatic Calculator (Edsac) restoration project
recently reached a key milestone. Edsac is built of 3,000 valves (vacuum tubes)
spread across 140 separate shelves.
Identifies You and Helps QST
In the early 1930s, QST magazine (ARRL's
monthly publication) usually ran a line at the bottom of every page in the
back half of each issue that said, "Say You Saw It in QST - It Identifies You and Helps QST." They
even got the capitalization correct (all lower case short prepositions and
conjunctions, but I digress). The December 1933 edition was a bit different,
however, in that all the left-hand pages had the message translated into one of
fourteen different languages while the right-hand pages used English. I deemed that
discovery cool enough to scan and post here. Since the only languages I speak with
any fluency are English and Pig Latin, I took the trouble of entering the English
sentences into the Google Translator engine for each language...
Radio Amateur Exhibit
The
1933 "Century of Progress" World's Fair, held in Chicago, was
a big deal on many fronts. Life in America and around the world was changing rapidly
due to the widespread introduction into homes a decade earlier of electrical and
telephone service, indoor plumbing, and associated appliances. The state of the
art was a modern wonder. Transportation had been made affordable to many families,
and leisure time was becoming more abundant. If it were not for the advent of the
stock market crash in 1929, economies would be thriving because there was so much
cool stuff to be had. Many people had taken up the hobby and/or profession of wireless
communications, so a display was included on the fairgrounds for the craft. An interesting
consequence of a combination of noisy (electrically) electromechanical
wonders being promoted and the desire to demonstrate working amateur radio equipment
was a necessity to locate the two as far apart as possible...
Started June 26, 2013
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RF Xcvr MPMP Modules Control
The DTS Series and EUR Series
RF transceiver modules combine a low power wireless transceiver
with a powerful multipoint-to-multipoint protocol controller to form an effective
UART-to-antenna wireless communication solution. The modules use a wide band digital
modulation technique known as Digital Transmission System (DTS) and are capable
of replacing wires in almost any RS-232/422/485 application. This system has a higher
output power, giving it a range of up to 1 mile / 1.6 km line of sight
without having to limit duty cycle, hop channels or the expense of a DSSS system.
Accurate Clock
The National Company, of Malden, MA, which
made this cesium-based
Atomichron in the mid-to-late 1950s, began life as a toy manufacturer.
It had an output frequency at the nominal resonance frequency of cesium - 9192.631830 MHz
- and was accurate to better than a second in 600 years. The unit was 7 feet tall
and weighed 500 pounds. Modern cesium standards are more stable and are portable.
As of January 2013, the NIST-F1 cesium fountain primary frequency standard is accurate
to within one second every 100 million years!
Threshold Detector
PMI Model
CDT-2M18-30-BB Options DE, D is a threshold detector that operates
over the 2 MHz to 18 GHz frequency range. This model has a low insertion
loss of 2.5 dB maximum and operates over an input power range of -30 to 0 dBm.
The threshold level is adjustable and the output signal is TTL positive logic. In
addition to the threshold detector, this unit offers an analog detected output voltage
of 0 to 2.5 VDC.
to Write on Graphene 'Paper'
This new technology could be a relatively
simple and inexpensive method of creating permanent, high density records storage.
Using an
electron beam, the planar hexagonal carbon
matrix of graphene (2-dimensional by definition)
is disturbed and replaced by a 3D clump of carbon atoms that provide a discernable
relief easily recognized as printing under a microscope. While the print could be
similar to a normal printed page, it might be more useful to encode the information
in some other form that will require decryption to read. Magnetic and optical digital
storage media is notoriously non-permanent due to cold flow and migration of localized
storage domains. This process eliminates that problem.
and Contactless Ring
You have probably heard proposals for 'smart
guns' that will only fire when owners wearing special rings are in possession. Here
is a near field communications
(NFC)
ring that permits only its wearer to use a cellphone, tablet, or other NFC-enabled
device linked to its code. Doing so eliminates the need to enter a password for
access. According to an
NFC World report, the ring contains an IC that can store
personal contact information as well allowing the wearer to voluntarily "share"
certain details about him/herself (why would you do that?) simply via
proximity contact. Initially, the ring will only work with Geak's devices, but plans
are in the works for more widespread adoption.
Offer eBook on RF Design
AWR Corporation announces a new eBook,
RF Electronics: Design and Simulation, which is available free
of charge to students, graduates, professors and industry professionals through
AWR's new Professors in Partnership™ web portal. Developed by adjunct associate
professor C. J. (Keith) Kikkert of James Cook University School of Engineering and
Physical Sciences, Townsville, Queensland, Australia, the book describes the use
of AWR's Microwave Office® and
AXIEM® software
to design RF electronic devices for applications such as amplifiers, radar, mobile
phones, Bluetooth, and WLAN.
Most regular RF Cafe visitors will probably
not be too interested in this article, but there are a lot of people who build and/or
repair vintage radio gear and search the Internet for helpful information. Having
built a couple
crystal radio sets as a kid, I've always been amazed at how a
few picowatts of RF energy can be received, processed, and heard through an ear
plug without the need for external power from a battery. Speaking of crystal radios,
I remember one time while working as an electrician in Annapolis, MD, (prior
to entering electronics) I had a telephone handset for use in communicating
with other electricians in a building I was wiring, and it picked up the local AM
radio station. A pair of the old style handsets...
"It's stupidity. It's worse than stupidity:
it's a marketing hype campaign." - GNU founder
Richard Stallman on embracing Cloud Computing for its ostensibly
"free" data storage on uncontrolled servers rather than on your local machine.
10 GHz Frequency Synthesizer
Phase Matrix's newest addition to the
QuickSyn® line of microwave frequency synthesizers is a 10 GHz
synthesizer housed in a very compact package, only 4 x 4 x 0.8 inches. The
new synthesizer, model
FSL-0010, employs the revolutionary phase-refining QuickSyn® technology. The
new Quicksyn® Lite synthesizer is less than half the size of the full featured 10
GHz and 20 GHz QuickSyn® synthesizers, yet it performs with wide coverage
(0.65 to 10 GHz), fine resolution (0.001 Hz resolution),
fast frequency switching (100 μs), and exhibits instrument-grade
spectral purity.
The folks
at Rev Response have a pretty big collection of white papers on a very wide range
of subjects that are free for downloading. Well, not quite free - they do require
you to sign in, but no $$$ is involved. I make a few pennies on each download, so
you're helping to support RF Cafe if you participate. Here are a few of the newer
ones that might interest you:
- 2012
Laptop Buying Guide
-
Rapid Color 3D Modeling
and Printing
-
Your Guide to Create
Professional Documents
on Word
-
Scientific Instrument and
Medical Device Makers
Exploiting 3D Interactive
Technology
-
Bring Your Own Device (BYOD) Policy Guidebook
for June 23, 2013
Take 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.
Restoration Project
After searching occasionally for many years
for another Crosley 03CB radio in a location close enough to drive for pick-up,
I finally saw one on Craigslist in Harrisburg, PA, about 300 miles from my home
in Erie, PA. Melanie and I picked it up yesterday. It needs - and will receive -
a total restoration for both the cabinet and the electronics, but it appears to
be in better condition that my first pre-restored
Crosley 03CB. This radio is Chassis #95. If you look at the photo
of the first radio , you will notice that the tuning dial has no cover over it.
I never knew there was supposed to be a glass bezel in front of the dial...
Sent to Just 10 Addresses
Think the illegal alien problem is just made
up? Here is the IRS's own 2012 fraud report showing more than $86 million sent
to just 10 addresses. See
Figure 5 on page 17. In Atlanta alone, a single address for 23,994
'Unauthorized' (aka Illegal) Aliens received payments totaling $46M. This crap is
costing our economy jobs by requiring working citizens to pay the tab for this.
It also feeds into the massive fraudulent voting scheme for one party and suppression
of voting by the other party. We now have a politico-economic
oligarchy,
folks. Congratulations.
Here are a few
more useful stories on the tech job market and job hunting. Enjoy.
-
5 Negotiation Tips from
Steve Jobs
-
Google Says GPAs Are
Meaningless for Recruiting
-
9 Qualities of Truly
Confident People
-
TWC Offering New
Teleworker Support for
Businesses
-
13 Must-Have Mobile Apps
for Business
-
4 Extreme Habits of Highly
Successful Remote Teams
I will be travelling on Friday with limited
e-mail access. Responses will probably be delayed for a few hours. I apologize for
any inconvenience.
Here is a fairly simple quiz on
AC circuit analysis. If you are not already comfortable with adding
series and parallel circuits containing resistors, capacitors, and inductors, you
will appreciate the simple formula presented that will keep the sweat level down
;-) OK, pick up you pencils... now.
Electronics hobbyists are always anxious to
hear the announcement of a new device that is forecast to revolutionize the tech
world. In the late 1950s something as relatively tame as a
crystal photocell satisfied that urge. Today it takes something
like a negative refractive index metamaterial to invoke the same sense of awe and
wonder. Those were simpler times, but then again even today's beginners in the world
of electronics circuit designing and building have to start somewhere, and these
types of circuits are as good as any place.
for the TV Industry
I wasn't able to verify Dr. Baker's
(VP of GE) prediction in 1957 of what the state of the television industry
would be by 1960. He said 10 million sets would be sold in 1960 vs. 7.5 million
in 1957. Some recent sources claim there were as many as 52 million TV sets total
by 1960, so he might have been right. Transoceanic scattering techniques were thought
to be the method of choice for television broadcasts, but we know that ultimately
relay satellites would win out. It wasn't until 1962 that the Telstar bird carried
the first TV signals, however. "Truly portable" transistorized TVs would be appearing...
Here is a little insight into early
speech processing research by the Bell Telephone Laboratories.
1957 was the early era of real-time digital processing where the need to cram more
calls into less signal space (bandwidth) led to sampled systems - 1:6 in the case
of this advertisement from Bell that appeared in Radio & Television News.
Engineers of the day would be amazed at how the state of the art has advanced since
then, both in mathematical techniques and in miniaturized hardware.
from IEEE's JobSite
IEEE
sends out an e-mail every week or so with links to stories on job hunting. Here
are a few of the most recent.
-
20 Questions to Ask
Yourself Before You
Relocate for a Job
-
The 10 Best Cities for
STEM Jobs Right Now
-
Didn't Get the Job?
You'll Never Know Why
-
Messages Galore, But
No Time to Think
MW & RF 2013 Survey Awards
AWR has won in two categories in the first annual
Microwaves & RF magazine "Best of Microwaves & RF" awards. The company won the Best
Training and Education category and was first runner up in the Best Supplier Industry
Blog category. The winners were determined through a recent survey that went
out to readers of Microwaves & RF magazine inquiring about their favorite online
tools for keeping up to date within the microwave/RF industry.
for Long-Time Support
RFtronics develops both turnkey and custom solutions for the
RF telecom equipment designers
and manufacturers. Currently, our product line includes high power couplers, splitters
/ combiners and filters between 1 MHz and 3 GHz. They have more than 20
years experience in the RF/microwave design and manufacture, with the agility of
a small company and the production capabilities of a larger-sized, high-volume manufacture.
RFtronics will usually deliver prototype quantities (less than 50 pcs)
directly and for larger orders the design will be transferred to our manufacturing
partner.
Consequences to Follow?
A recent
NY Times article reported on a
court
ruling in favor of a couple interns who claimed they were not fairly paid for
their work. Author Steve Greenhouse points out that while it could be a victory
for the litigants, ultimately it could bode poorly for internship programs. Legal
precedence is widely referenced and applied by legal teams, and is notoriously difficult
to overturn. This particular internship involved work on a movie production set,
but expect the decision to ripple through to even engineering and science business
programs. An estimated 1,000,000 internships are hosted each year in America, a
significant portion of which could be eliminated out of an abundance of caution
and fear of being sued. Is this another "careful what you wish for, you might just
get it" scenario?
Microstrip Lines and Slotlines, by Ramesh Garg, Inder
Bahl, and Maurizio Bozzi. Planar transmission line technology has progressed considerably
due to developments in UWB communications, imaging, and RFID applications. In addition,
the simultaneous demands for compactness of wireless electronic devices while meeting
improved performance requirements, necessitates increased use of computer-aided
design, simulation, and analysis by microwave engineers. This book is written to
help engineers successfully meet these challenges. This book was used as the basis
for RF Cafe Quiz #50.
You might have read about the recent U.S.
Patent and Trademark Office (USPTO) law that changes policy from a
'first to invent' to a 'first to file'
system. It was meant to reduce the amount of work required by patent examiners and
to reduce litigation by eliminating the heretofore potentially subjective nature
of determining who was the 'real' inventor of an idea. Previously, if a person could
prove via formal dated notes, witnesses, etc., that he was the first to manifest
an idea in the form of a working model, there was a good chance that an existing
patent could be reassigned. Now, it is almost purely a matter of who gets the earliest
timestamp for having been received at the USPTO. This short piece in Inc magazine
discusses the new
patent filing issue.
in Appreciation of Support
Since 1994, leading wireless electronics companies have relied on 3Gmetalworx
to deliver cutting edge solutions for advanced
RF/EMI
PCB-level shielding requirements. From prototyping and design services
to JIT manufacturing supply, our clients depend on us to provide a seamless service
pathway supporting entire product lifecycle. All shields can incorporate these
features, as well as your custom needs:▪Engagement tabs, trace/component relief,
tuning/access openings, thermal relief.
Larry Wolfgang
has a good article in the May 2013 edition of QST titled "Contributing to Science." In it he recalls a few examples of how
amateurs have helped professional
scientists and engineers advance the state of the art in wireless communications.
For instance Pat Dyer, WA5IYX, conducted an 11-year study of mid-latitude
sporadic
E, and Dave Olean, K1WHS, built a
magnetometer
to predict aurora to aid in 144 MHz DX. Hams also discovered
trans-equatorial propagation. Mr. Wolfgang suggests that pursuing
a meaningful scientific investigation of your own or maybe by your club would be
a worthwhile and satisfying endeavor. BTW, while writing this I happened upon a
resource for current QST articles on
EBSCO Host website, which is significant because non-members of
ARRL cannot access their online editions.
Started June 18, 2013
Please take a moment and
vote in this poll. No sign-in-required. Results are displayed automatically. Thanks!
See current.