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 ...
If my counting is correct, by 1952 only 33
of America's 48 states (Hawaii and Alaska weren't admitted until 1959), and Washington,
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
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
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
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 ...
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
2019's Best Jobs
Why Women Need to Network
The Many Ways to Get a Job Before Graduation <more>
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 ...
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! ...