Today in Science History -
Spectrum crowding issues began almost as soon
as wireless communications was started. Early spark transmitters spewed RF radiation
all over the place, and (nearly) filterless receivers picked it up to convert the simple
CW signals into dits and dahs from Morse code messages. As more people climbed onto the
radio bandwagon with ever increasing transmitter power levels and receiver sensitivity
levels, differentiating between desirable and undesirable signals became a frustrating
task - like trying to hold a conversation in a room full of yakking people. Filters on
transmitters and receivers provided much relief. User numbers continued to grow and phone
(voice) communications, which occupies a few kilohertz of bandwidth instead of only a
hundred or so Hz, started straining spectrum availability yet again. Newer modulation
techniques like single sideband freed up some space, but then the digital age came along
and started sucking up spectrum again. During the entire time, advances in electronic
always have been and always will be a daunting subject to a lot of people. For electronics
types, the issue of when to multiply the
logarithm of the ratio by 10 or by 20 seems to be the biggest stumbling
block. After many years of working with decibels, it becomes second nature. There are
still instances, though, where I see seasoned engineers and technicians routinely confuse
unreferenced decibel units (dB, the logarithm of a ratio) with logs of ratios referred
to some base value (dBm, dBV, etc.). The bel unit was originally created to quantitatively
assign changes in perceived levels of sound loudness...
"There's a serious cyber warfare problem that
may be affecting some deployed U.S. military and aerospace mission-critical embedded
computing systems, and nobody really wants to talk about it. It has to do with a computer
chip no bigger than a grain of rice that's suspected of being installed by Chinese intelligence
agencies on embedded servers made by San Jose, Calif.-based Super Micro Computer Inc.
tiny chips may be enabling China and other U.S. adversaries to monitor
the inner workings of military computers and the data they are processing. Super Micro
embedded computing servers are now, or in the past have been in use by some of the world's
largest corporations, including Amazon and Apple. They also may now, or in the past have
been in use ..."
Having been out of the RF system design realm
for a few years, I do not have much cause to think about
mixer spurious products anymore. I wonder these days how many designers even do much
in the way of frequency planning in conversion systems? Are the RF, IF, and baseband
frequencies as so well defined for most of what is done in the wireless world that all
the spurious product issues have been solved and there are few people who need to calculate
mixer spurious product frequencies and powers? If there is a need, what methods are currently
being used? Do you still cobble together spreadsheets and/or MATLAB worksheets using
equations like those presented here, do you have a favorite smartphone app, a compact
program on your computer, or are you using one of the two or three uber sophisticated
and super expensive design engineering programs ...
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"The technique makes metals smoother and more flexible
for better current flow throughout a metallic circuit. Cellphones, laptops, tablets,
and many other electronics rely on their internal metallic circuits to process information
at high speed. Current metal fabrication techniques tend to make these circuits by getting
a thin rain of liquid metal drops to pass through a stencil mask in the shape of a circuit.
But this technique generates
metallic circuits with rough surfaces, causing electronic devices
to heat up and drain their batteries faster. Future ultrafast devices also will require
much smaller metal components, which calls for a higher resolution to make them at these
nanoscale sizes. This requires molds with higher and higher definition ..."
are moving into the colder days of the year in the northern hemisphere. The normal high
temperature here in Erie, Pennsylvania is around 49°F (35° today with snow on the ground
for the last three days). It is the time of year that causes those less appreciative
of cold weather to conjure up memories of warm summer days with green leaves on tree
branches and colorful flowers in the garden. For those of you like me who actually prefer
the cooler weather, this
Carl & Jerry story about making snow by blasting clouds with ultrasonic energy
just adds to my appreciation of the onset of winter and visions of a white Christmas.
To date there has been no major, efficient progress in the field of snowmaking or rainmaking
(other than seeding clouds with silver iodide). Ski resorts still need sub-freezing weather
Paul Rako posted a great piece on the Electronic Design
website about University of Alabama professor Kenneth Kuhn's
HP Museum. If you
have a Pavlovian response at the mere mention of vintage HP test equipment, then you'd
better put on a bib before visiting his website. Be sure to see the
page. Says the good prof, "This web site is devoted to the history of test equipment
produced by the Hewlett-Packard Company which is now known as Agilent Technologies [Keysight
by now - KRB]. I own a huge collection of vintage Hewlett-Packard test equipment, catalogs,
equipment manuals, and Hewlett-Packard Journals. I also own probably one of the few still
existing HP210A square wave generators ..."
According to this 1972 article in Popular
Electronics magazine, cable television began around 1950. The system was very different
that what we have nearly 70 years later. The familiar acronym CATV does not stand for
CAble TeleVision, but rather
Community Access TeleVision. CATV, as originally implemented, was a means of bringing
broadcast TV to areas either too remote or too shielded from over-the-air (OTA) RF signals
to provide good signal reception. Depending on the need, CATV could range from re-broadcasting
of signals into targeted areas or sending signals through cable (originally unshielded)
to individual homes. As you might expect, opponents of the new system predicted that
such a scheme would eventually be the kiss of death for local broadcasters since large,
well-funded conglomerates would be able to dominate programming selection and dry up
Anatech Electronics, Inc. offers the industry's
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RF and microwave filters and filter-related products for military, commercial, aerospace
and defense, and industrial applications up to 40 GHz. Anatech has introduced three
new filter designs: a 1533 MHz cavity bandpass filter with SMA connectors, a 850 MHz
LC bandstop notch filter with SMA connectors, and a 698-942/1710-2145 MHz single
in/out duplexer filter with N-type connectors. Custom RF filters designs are used when
a standard cannot be found, or the requirements are such that a custom approach is necessary ...
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they can help your project ...
"Griffith University researchers have demonstrated
a procedure for making
precise measurements of speed, acceleration, material properties
and even gravity waves possible, approaching the ultimate sensitivity allowed by laws
of quantum physics. Published in Nature Communications, the work saw the Griffith team,
led by Professor Geoff Pryde, working with photons (single particles of light) and using
them to measure the extra distance travelled by the light beam, compared to its partner
reference beam, as it went through the sample being measured - a thin crystal. The researchers
combined three techniques - entanglement (a kind of quantum connection that can exist
between the photons ..."
Echo 1 was put into
orbit on August 12, 1960. This article was written 2½ years earlier in 1958 by Radio-Electronics
editor Hugo Gernsback. A technology visionary and prolific inventor and writer, Mr. Gernsback
astutely outlined the vast number of advantages that had already been and would in the
future be afforded the science community by virtue of a satellite's perspective from
space. Two of the Soviet Union's Sputnik satellites had revealed the surprisingly irregular
shape and gravitational influence of the Earth, information about the upper atmosphere,
and aspects of
space environment effects on radio communications. America was scrambling
to catch up. Gernsback and others postulated the configuration of active relay transceivers
powered by solar cells and storage...
Anokiawave has found a good man in Alastair Upton.
He was a highly respected and well-liked product line manager at RF Micro Devices when
I worked there in the last decade. He was always appreciative of the competitor device
teardown reports I wrote for him or for prying things open for him without breaking them.
"Anokiwave, an innovative company providing highly integrated IC solutions for millimeter-wave
markets and Active Antenna based solutions, today announced the appointment of
Alastair Upton as Senior Vice President of Business Development.
In this role, Upton will lead the company's strategic accounts, manage partnership programs,
and provide telecommunications expertise to the company. This appointment comes at a
strategic time for Anokiwave with tremendous opportunities for continued growth in the
I remember in one of my circuits classes in college
when the gyrator was introduced, and I thought it was an ingenious invention. The gyrator
circuit, implemented with an opamp and a couple resistors and capacitors, changed its
measured impedance type from that of a capacitance to that of an inductance. That is,
its impedance represents an R + jX Ω
format. Frequency limits are imposed by a combination of the self-resonant frequencies
of the resistors and capacitors as well as the gain-bandwidth product of the opamp, and
power handling is primarily limited by the opamp's voltage and current capabilities.
You might ask why, with all those constraints on its use you would even want to use a
gyrator circuit? The answer is that within its limitations, the gyrator often represents
a less expensive and more compact version of a physical inductor ...
The convenience and awesome power of the Internet
has for practical purposes always existed for anyone born in the 1990s or later. Having
been a teenager in the relatively prehistoric 1970s, the possibility of smartphones and
cars run by microprocessors was the domain of
Illustrated magazine visionaries who also dreamed up flying cars, personal nuclear
power generators, and a pill to cure the common cold. Nothing that would come to fruition
in my lifetime - right? Sure, this is just yet one more person's nostalgic waxing about
before the Internet was, but go ahead and take a look. It all strikes
a familiar chord with me ...
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"FCC has already allocated 12.55 gigahertz of
millimeter wave spectrum. Millimeter wave spectrum is key to delivering
on the ultra-high throughput speeds associated with 5G. In the U.S., the Federal Communications
Commission is gearing up auction 28 GHz and 24 GHz licenses on Nov. 14, and domestic
operators AT&T and Verizon are launching their first 5G services using the 39 GHz
and 28 GHz bands respectively. This momentum, coupled with other regulator-led activity
in key global markets, highlights the fundamental role of millimeter wave in 5G. In Europe,
U.K. officials plan to allocate 26.5 GHz to 27.5 GHz in the 2020 timeframe as do their
counterparts in Spain, Austria ..."
Don't let the title fool you. This is not a "bees-birds-and-flowers
routine" being provided to Barney by his boss, Mac. It turns out to be a brief introduction
into the fine art of
troubleshooting intermittent problems in radio and television circuits. As is usually
the case, while the specifics of the scenarios Mac describes might not apply to your
challenge at hand, the general philosophy always does. It is basically the old process
of elimination where after rapping components mechanically and/or heating or cooling
them in hopes of observing a tell-tale change in performance, the next step is to divide
the suspected circuit portion in half (electrically, but sometimes also physically) and
look in one direction. If the problem