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5 of the January 2019 homepage
archives.
Thursday 31
By now, engineers and scientists have managed
to replace most vacuum tubes with solid state devices - at least for consumer products.
The one place tubes remain are in microwave oven. Those klystron tubes operate in
the 2.4 GHz band and typically output ranging from about 500 W to 2 kW.
No doubt materials and methods have changed since the 1950s, but fundamentally klystrons
of today are the same as klystrons then. Between this article and Part 1 that
appeared in the April 1952 issue of Radio & Television News
magazine, authors Joseph Racker and Lawrence Perenic provide a very nice
introduction on the topic. According to the Wikipedia entry, the name "klystron"
comes from the Greek verb κλύζω (klyzo) referring to the action of waves
breaking against a shore, and the suffix -τρον ("tron") meaning...
Glenn Robb is a busy guy. I addition to running
his Antenna Test Labs facility, he has created numerous educational projects. Late
last year he made news with 3D-printed microwave feedhorns, and this latest endeavor is
this 4D plot of the popular
Raspberry Pi printed WiFi band PCB antenna. Says Glenn, "This
antenna example is a common and popular option for most IoT devices operating in
the 2.45 GHz WiFi ISM band. It is a PCB antenna designed by Proant AB and
replaces the dielectric SMT chip antenna previously used the Pi's. The design is
a planar resonant cavity using two sets of SMT capacitors to setup resonances in
the 2450 and 5800 MHz WiFi ISM bands. While small antennas are convenient and
often inexpensive, they compromise performance for their size trade-off. This
example antenna evaluation will show the actual radiation efficiency..."
Rohde & Schwarz and Microwave Journal
will present a free webinar on February 13, titled, "5G mmWave: A Challenge for Device Testing and How to Solve It."
Günter Pfeifer discusses how 5G NR in the sub 6 GHz frequency range (FR1) can be
seen as a natural evolution of LTE to achieve higher bandwidth and more
flexibility on the physical layer in order to realize all the new and additional
use cases defined for a next generation mobile network. "The real technical
challenge, however, comes with 5G mmWave (FR2), which opens up a new level of
complexity in device development. mmWave frequencies imply measurement
challenges that call for new testing approaches. In this webinar, we take a
closer look at the major challenges mmWave brings and discuss innovative test..."
I remember my first experience with
Monte Carlo analysis was in my first job at General Electric
in Utica, NY, immediately after graduating from UVM with a BSEE degree. It involved
using the early version of
EEsof Touchstone that used Spice type netlist circuit description
entry. The topic was a bank of switchable bandpass filters for an airborne EW receive
unit. I also used OmniSys for optimizing the RF path. It was mesmerizing watching
the multicolored lines get drawn on the screen as the software converged on a solution
- or didn't. Charles Hymowitz has an interesting article on the EDN website titled,
"Monte Carlo Gone Wrong"...
Watching this video of
miniature satellite launches
from a spaceborne pod is both cool and spooky. It reminds me of an alien
invasion vessel deployment from a sci-fi movie. Per the report: "A company has
launched hundreds of small satellites capturing over a million photos of Earth
each day for commercial use, offering unimagined possibilities and consequences.
Planet Labs, the satellite company, has launched hundreds of small satellites
for commercial use, such as monitoring the health of crops. They get over a
million photos from them each day. 'I'm always astonished that almost every
picture we get down, we compare it to the picture from yesterday and something
has changed,' says one of the company's founders, Will Marshall. Planet Lab has
200 customers, none more important than the U.S. Government..."
PCB Directory is the largest
directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and
Design Services on the Internet. We have listed the leading printed circuit
board manufacturers around the world and made them searchable by their
capabilities - Number of laminates used, Board thicknesses supported, Number of
layers supported, Types of substrates (e.g., material, flexible, rigid),
Geographical location, and more...
Wednesday 30
If my counting is correct, by 1952 only 33
of America's 48 states (Hawaii and Alaska weren't admitted until 1959), and Washington,
D.C., had
television broadcasting stations. That most of the early television
experimentation occurred on the east coast is apparent by looking at the number
of stations there compared to the west coast. You might think California would
have the largest amount of TV stations, but it only had 11 located in 3 cities.
New York, on the other hand, had 13 in 7 cities. Ohio had 12 stations in 5
cities, and Pennsylvania had 7 stations in 5 cities, one of which was my town of
Erie. Vermont, New Hampshire, Mississippi, Wyoming, both Dakota, and Oregon were
among those with no television stations by 1952. That seems unbelievable since
that was only 67 years ago, but evidently was so. The network "lines" included
microwave repeaters to reach from coast to coast. On September 4, 1951, AT&T
opened the network by televising a presidential address...
Planar Monolithic Industries (PMI) recently
introduced three new products in their extensive line of
RF and microwave
components. Included are a 2.0 to 18.0 GHz high speed single pole six throw
reflective switch capable of switching within 15 ns, a 2.0 to 18.0 GHz 8-Bbit
vector phase shifter, and a 2-channel switch filter bank with a low-pass 8.62 to
8.70 GHz filter and a 8.0 to 26.5 GHz bandpass filter. Contact PMI today for
more information...
I have never seen study-at-home audio-visual
(AV) physics courses offered by Albert Einstein or AV courses on chemistry promoted
by Ernest Rutherford, but I can now say I have seen study-at-home AV courses offered
by electronics pioneer Lee de Forest. This full-page advertisement for the
de Forest's Training, Inc., company of Chicago, Illinois, appeared in a 1945
edition of Radio-Craft magazine. The vaunted (at least by the company)
"Syncro-Graphic" training was an early attempt at the paperless classroom. The
student watched films reels of instruction rather than "frequent flipping of
pages to refer back or ahead to illustrations mentioned in text." It would be
another 50 years before useful computer-based-training (CBT) courses became
available for home use, but you have to give the "Father of Radio" credit for
being ahead of his time in instruction techniques...
Along with the rapidly advancing technology
of self-driving vehicles and sensor-assisted driving has come crowded spectrum in
the mm-wave bands (see "Why Are Automotive Radar Systems Moving from 24 GHz to 77 GHz?").
Sefa Tanis, of Analog Devices, has published an article titled, "Automotive Radar and Congested Spectrum: Potential Urban Electronic
Battlefield," in Microwave Journal. "As automotive radars become
widespread, the heavily occupied RF spectrum in an urban environment will
resemble an electronic battlefield. Radar will face a combination of
unintentional-even intentional-jamming, and designers must implement
counter-jamming techniques like ones used in electronic warfare (EW)..."
RF Cafe typically receives
8,000-15,000 website visits
each weekday and about half that on weekends. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the
world. With more than 7,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images. New
content is added on a daily basis, which keeps the major search engines
interested enough to spider it multiple times each day. Items added on the
homepage often can be found in a Google search within a few hours of being
posted. I also re-broadcast homepage items on LinkedIn, Facebook, and Twitter.
If you need your company news to be seen, RF Cafe is the place to be. Banner
advertising begins at $150/month...
"In power electronics, the silicon technology
that predominates today will no longer be able to meet the growing demands in the
foreseeable future. Scientists from the University, the Fraunhofer-Gesellschaft
and power centers have joined forces to research a novel material structure that
will meet the requirements of industry for future components much better. Scientists
therefore are investigating a rather exotic material most electronics engineers
probably never have heard of:
ScAIN.
Two main factors are responsible for the growth of the electronics market: the
automation and digitization of the industry as well as the increasing awareness
of ecological responsibility and sustainable processes. Energy consumption..."
Empower RF Systems is a global leader in
power amplifier solutions. Empower RF Systems is an established and technologically
superior supplier of high power solid state RF & microwave amplifiers. Our offerings
include modules, intelligent rack-mount amplifiers, and multi-function RF Power
Amplifier solutions to 6 GHz in broadband and band specific designs. Output
power combinations range from tens of watts to multi-kilowatts. Unprecedented size,
weight and power reduction of our amplifiers is superior to anything in the market
at similar frequencies and power levels...
Tuesday 29
Less than half a decade had passed when Radio &
Television News editor Oliver Reed wrote this piece extolling the
virtues of the transistor and how "it may well revolutionize the entire
electronics industry." If you have followed a lot of my postings from the
vintage electronics magazines here on RF Cafe, you are well aware that there was
a lot of resistance to and doubt about the future of semiconductors. Naysayers
had the same kind of reaction to the advent of the horseless carriage
(automobile) and locomotive, relativity and quantum mechanics, and even curative
medicines. Point contact transistors were still largely in use, but were costly
compared to the relative simplicity and low cost of junction transistors once
the manufacturing details were worked out - which, as we now know, happened very
rapidly. By 1965 the process was so refined that Gordon Moore...
Everybody has to start somewhere when learning
about digital logic, and Roger Secura has provided just what's needed with "The Beginner's Guide to Digital Electronics," on the Nuts &
Volts website. "This article was written specifically for the newcomer to
the field of digital electronics. If you've always wanted to know how the
digital world works, then keep reading. You don't need to know calculus,
algebra, or any complex formulas to finish this article. The only requirements
are an interest in digital electronics and a desire to learn. Since you're
reading this paragraph, obviously you're at least a bit curious about the
digital world. Fortunately, curiosity is half the battle to enlightenment..."
Keysight Technologies, a leading technology
company that helps enterprises, service providers, and governments accelerate innovation
to connect and secure the world, announced
PathWave Memory Designer, a new double data rate (DDR) memory simulation capability
that is part of
PathWave Advanced Design System (ADS) 2019. The new capability makes it easy
for developers to compare simulated data with actual measured results, reducing
the time required to complete product development workflows. DDR memory designs
grow more complex with each new generation, and simulation and test
configuration also grow in complexity, resulting in longer simulation and test
setup times. The added complexity makes it harder to correlate simulation and
test data, resulting in less confidence in designs, longer troubleshooting
cycles..."
What's That Signal's Bandwidth?
Bob Witte has a brief primer titled, "What's That Signal's Bandwidth?" on the EDN
website. "The term bandwidth is used and abused in many situations. I recall one
meeting where the word was used to refer to: the frequency content of a
particular signal, the frequency response of a specific circuit, the speed of
our local area network and the human capacity of the organization. 'We just
don't have the bandwidth to handle the workload right now.' I don't think anyone
else noticed, but I found it humorous. Signal bandwidth Engineers will ask the
question 'how much bandwidth do I need for that signal?' Typically, the question
relates to making sure that the signal can propagate through a component or
system and come out the other end without any degradation..."
"Looking to enhance accuracy, the concept
uses Earth-based cars sharing data and generating corrections. In a patent application
filed in 2017 and made public last month, Tesla describes a technology that it believes
will result in more accurate
GPS positioning.
The proposed invention would increase positioning accuracy via determining and
applying offsets - corrections - in various ways and sharing this information
between vehicles. Tesla describes a system of matching camera data with vision
maps to detect the exact location of a vehicle. In essence, the system involves
using camera sensors on Tesla EVs to fine-tune the GPS data..."
Anatech Electronics (AEI) manufactures and
supplies RF and microwave filters
for military and commercial communication systems, providing standard LP, HP,
BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF
filter and cable assembly products are published in our website database for
ease of procurement. Custom RF filters designs are used when a standard cannot
be found, or the requirements dictate a custom approach. Sam Benzacar's monthly
newsletters address contemporary wireless subjects. Please visit Anatech today
to see how they can help your project succeed...
Monday 28
The history of electrical current is replete
with tragic incidences of maiming and death caused by ignorance and/or inattention
to known danger. Having been involved in both the electrical wiring and the electronics
fields since the 1970s, I am quite aware of the legion of hazards present when current
flows. My tool box contains screwdrivers and lineman's pliers with notches of melted
metal from inadvertent contact between differences of potential in circuit breaker
panels and electrical wall boxes. Once you experience the thrill of a sudden blinding
flash, unique buzzing sound, and smell of burning hot steel, you'll never forget
it. Those incidences could have been avoided with more careful work practices. A
lot of people have been
electrocuted, though, through no fault of their own, if ignorance (as
opposed to stupidity) is a valid excuse. Early radios, televisions, and other
household appliances did not have a safety ground...
It has been a few months since I posted a
list of useful articles on engineering and other technology job search and career
enhancement topics from around the Web. Very noticeable when reviewing the subjects
of most of these websites is a very high concentration on social issues rather than
on job performance and competency...
•
Why Companies Need Engineers with a Creative Bent •
How to Answer Common Interview Questions •
Things to Double-Check
Before Submitting a Cover Letter •
Report:
2019's Best Jobs •
Why Women Need to Network •
The Many Ways to Get a Job Before Graduation
Q: How do you make sure as many men as possible
read your news release about a radiation protection suit for long-term space flight?
A: Use lead photo of two women with terraced vests, along with an opening line of,
"Meet Helga and Zohar, the dummies destined for a pioneering lunar flyby to help
protect space travelers from cosmic rays and energetic solar storms." The con is
that you are never explicitly told those two women are not "twin dummies" Helga
and Zohar. The Japanese have created some incredibly lifelike dummies, but none
this convincing. A quick Google search turned up info explaining why the
real Helga and Zohar,
if used in that lead photo, would not have garnered nearly as much attention. A
more important question might be who... or what... is the biggest dummy? Helga,
Zohar, the women in the photo, or me (for digging into the details of the
story)?...
The U.S. Army's Signal Corps was set up to
"exercise supervision over signal communications literally from the Pentagon to
the foxhole." Created in 1860 at the suggestion of a military doctor, the
Signal Corps originally used a system of flag waving for messaging dubbed
"wigwag" and graduated to overseeing the nationwide telegraph network six years
later. By 1870, members were tasked with establishing and operating a weather
forecasting service, so in 1907 when they created an aeronautical division it
was just in time for facilitating the nation's rapidly growing cadre of aircraft
pioneers (recall the Wright brothers had flown four years earlier at Kitty Hawk)
by providing en route weather information. Having already mastered the state of
the art that was radio and telephone...
"Researchers have created a field-effect
transistor using a single-crystal, 'paint-on' perovskite. Transistors, and the
conductive traces that connect them, are routinely created by the billions on
the surface of silicon wafers, which are later cut into the individual 'chips'
that power our computers, phones, watches, and countless other electronic
gadgets. But few people think much about how those silicon wafers are made in
the first place. It's quite tricky. Very pure sand (silicon dioxide) has to be
melted, at which point a seed crystal of elemental silicon is brought in contact
with the melt, which slowly deposits silicon atoms on the seed, ones that extend
the seed's crystalline lattice..."
Res-Net Microwave has a complete line of
precision RF & microwave components
including attenuators, terminations, resistors, and diode detectors for
commercial, military, and space applications. Products range from the small
flange type to large 2,000 watt connectorized power attenuators and/or
terminations at frequencies up to 26.5 GHz. In-house photo etch and laser trim
capability. Please check out Res-Net Microwave's website to see how they can
help with your current project...
Sunday 27
Each week, for the sake of all avid cruciverbalists
amongst us, I create a new
technology-themed crossword puzzle using only words from my custom-created
lexicon related to engineering, science, mathematics, chemistry, physics,
astronomy, etc. You will never find among the words names of politicians,
mountain ranges, exotic foods or plants, movie stars, or anything of the sort.
You might, however, see someone or something in the exclusion list who or that
is directly related to this puzzle's theme, such as Hedy Lamarr or the Bikini
Atoll, respectively. Enjoy!...
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
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