 Tuesday 28
 As with many areas of electronics communications,
much of both the initial and continued research in
atmospheric scattering of electromagnetic signals was/is done by amateur radio
operators. The phenomenon is routinely used for accomplishing long distance communications
(DX, in Ham terms) by exploiting the reflection property of ionized layers when
radio signals impinge at a certain angle. The portion of the signal that returns
to the transmitter location, when monitored, can provide information to the sender
about the height, distance, and frequency range of the reflecting atmospheric layer.
Some of the first indications of backscattering were noticed by radar operators
who would receive echo returns from "phantom" targets that were really atmospheric
reflections...
 "LoRa Alliance, the global association of
companies backing the open LoRaWAN standard for the Internet of Things (IoT)
low-power wide-area networks (LPWANs), has announced a new Certification Affiliate
option for certifying devices with the LoRaWAN standard. The new Certification Affiliate
program offers a path for non-LoRa Alliance members to obtain LoRaWAN device certification.
The LoRaWAN certification program includes full protocol testing, interoperability,
and RF performance, which is critical for open global standards. The Certification
Affiliate program will increase the number and breadth of LoRaWAN CertifiedCM devices
available in the market to serve the IoT needs of companies and users around the
world. LoRaWAN Certification is more important..."
 I don't know about you, but I really miss
the hard-wired POTS (Plain
Ordinary Telephone System) days of remote communications. Unless the conversation
was with an overseas telco system, there was never a noticeable delay where both
parties were constantly either 'stepping' on each other's words or having to consciously
wait before speaking to make sure the other guy has finished. Whether it be cellphone-to-cellphone
or cellphone-to-VoIP, nearly every conversation is annoying. Sometimes when one
party is on the POTS line with either a cell or Internet connection it can go well,
but if you want a hassle-free conversation (assuming the person you're talking to
is not a PiTA), you need a hard-wired connection on both ends. People loved to hate
Bell Telephone back in the day...
 ConductRF has developed many
RF connectors in recent years to enhance RF performance in our LSA series cable
assemblies. Low Profile SMA R/A male connectors that operate to 27 GHz are
just one example. Component Engineering challenges often require finding a "commonly
available solution," for a specific application that meet broad, often conflicting
requirements, determined by colleagues in electronics. Assuming knowledge of standards
like RG cables and widely available solutions, our expertise can be useful when
those will not work. ConductRF can provide options for higher frequency, lower loss,
greater mechanical integrity and more. When connector modules or jumping RF across
PCB's, try these RF cable assembly options from ConductRF...
 Have you seen this video yet? It qualifies
for reference on RF Cafe because it is
STEM-related. I first
saw it a couple months ago and have probably rerun it half a dozen times. It is
one of the funniest videos ever. Substitute teacher Mr. Garvey's extensive experience
as an inner city teacher doesn't quite work in this suburban classroom. I won't
spoil it for you by commenting, but be prepared to laugh yourself to the point of
tears.
 Nova Microwave is a leader in technically differentiated
electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control
critical commercial and military wireless telecommunications systems. Our staff
is dedicated to research and development of standard and custom design quality Ferrite
Circulators and Isolators from 380 MHz to 26.5 GHz. Available in single
or multi-junction topographies, the Nova Microwave product line of is specifically
designed for use in varied environmental and temperature extremes.
Monday 27
 Amateur radio operators - and all electromagnetic
spectrum users for that matter - have always lamented
crowded bands
and interference (QRM and QRN). That goes for licensed and unlicensed bands.
In 1976 when this editorial was printed in the ARRL's QST magazine, spectrum
occupation within allocated bands was defined by commonplace analog AM and FM methods.
Co-existence was generally not possible for operation within a common frequency
range. Spread spectrum modulation / demodulation changed all that beginning in the
1990s, but prior to then such schemes were largely the exclusive domain of military
communications, as were many other spectrum-saving methods which are commonplace
today. A big part of the reason is the significant advances in digital processing
hardware and software, along with declassification of some of the algorithms that
eventually found their way into cellphone, WiFi, and other commercial applications.
Given that many of the professional engineers...
 "Infineon Technologies has announced an agreement
with Blumio to jointly develop a wearable
blood pressure sensor based on Infineon's Xenxiv chipset. The new sensor is
expected to make a strong contribution to the wearable cardiovascular monitoring
device market, enabling continuous and accurate measurement without a cuff. The
project combines Infineon's radar sensor expertise with Blumio's software technology.
A kit combining the two technologies should facilitate time-to-market for easy integration
into blood pressure monitoring devices..."
 Aegis Power Systems is a leading supplier
of AC-DC and DC-DC power supplies
for custom and special applications. Aegis has been designing and building highly
reliable custom power supplies since 1995. They offer a complete line of switch
mode power supplies and power converters for a variety of markets including defense,
industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom,
and embedded computing applications. Design and manufacture of custom power supply
solutions to meet each customer's exacting specifications. Please visit Aegis Power
Systems today to see how they might help your project.
 Copper Mountain Technologies (CMT) is seeking
a
Lead RF Design Engineer to develop new VNAs for customers all over the
world. Our USB VNAs are next generation analyzers designed to meet the needs of
21st Century engineers. Our VNAs include an RF measurement module and a processing
module, a software application which runs on a Windows or Linux PC, connecting to
the measurement hardware via USB interface. The Lead RF Design Engineer will lead
a team of engineers developing new USB VNAs, meeting new customer requirements,
and evolving current product line. This individual will work closely with product
management, manufacturing and other engineering teams to ensure delivery of quality
solutions to customers. Take this opportunity to join a great company. Preferred
location for this position...
 Way...... back in 1992, RF Design
magazine ran a software contest. Those were the days when most engineers and hobbyists
wrote software in either Basic or Fortran. I happened to use Turbo Pascal, by Borland.
At the time, I was working as an RF engineer for Comsat, in Germantown, MD. Having
done a lot of frequency conversion designs in my previous work at General Electric,
and even more there at Comsat, I had already written a crude program to calculate
mixer spurious
products, so this challenge gave me the excuse I needed to refine the user interface
and add some creature comfort features like loadable mixer spur files and detection
of spectral inversion if present. Although I did not win the grand prize, I did
win the runner-up prize (along with, I think, a couple other people). The prizes
included having the following article published...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic
drawings! Every object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Symbols are provided
for equipment racks and test equipment, system block diagrams, conceptual drawings,
and schematics. Unlike previous versions, these are NOT Stencils, but instead are
all contained on tabbed pages within a single Visio document. That puts everything
in front of you in its full glory. Just copy and paste what you need on your drawing.
The file format is XML so everything plays nicely with Visio 2013 and later...
 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 for your military and commercial communications needs.
Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please
visit Anatech today to see how they can help your project succeed.
Sunday 26
 July 26th's custom
Radio Engineering crossword puzzle contains some words particular to radio,
radar, analog and digital circuits, components, and other tech-themed words and
clues. Each week for two decades I have created a new technology-themed crossword
puzzle using only words (1,000s of them) 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, find someone or
something in the otherwise excluded list directly related to this puzzle's technology
theme, such as Hedy Lamarr or the Bikini Atoll, respectively. Avid cruciverbalists
amongst us: the gauntlet has been thrown down.
Friday 24
 To be honest, I don't know whether
military electronics training commands the respect in private industry that
it did back in 1982 when I separated from the U.S. Air Force. If you left the military
within the last 20 years or so and care to share your experience with seeking civilian
employment, I'll be glad to add it here as a side note. Many of the electronics
technicians I worked with both as a tech myself and then as an engineer (after earning
a BSEE) got their initial classroom training in either the Air Force or the Navy.
There were probably some from the Marines and Army, but I don't recall any off-hand.
I hate to admit it, but I think the Navy vets were even more highly sought after
than we Air Force types. This 1969 issue of Electronics Illustrated...
 Copper Mountain Technologies'
University Kit is a complete solution designed to assist educational institutions
in teaching engineering students RF skills. The kit has three options of vector
network analyzer models and includes the calibration module, sample devices under
test (DUTs), and accessories necessary for an array of common VNA measurements.
CMT's University Kit is an affordable way to outfit the lab with RF measurement
equipment, providing a practical approach to vector network analysis and supporting
remote learning. Vector Network Analyzer options for the University Kit include
the CMT304U 2-port 3.2 GHz Analyzer, CMT804U 2-port 8 GHz Analyzer, and
the CMT808U 4-port 8 GHz Analyzer...
 Are we back to the WWII mindset of Use it
up. Wear it out. Make it do, or do without? Maybe so, according to this article:
"A perfect storm is brewing for consumer electronics Back [not "black"] Market marketplace.
The items it specializes in -
refurbished smartphones, PCs, tablets and the like - are in high demand as professionals
and students work from home during the coronavirus pandemic. In many regions of
the world, unemployment has skyrocketed, so consumers are increasingly budget-conscious.
Finally, by extending the lifecycle of consumer devices, e-waste - and the pressure
to continually upgrade electronics - is reduced. electronics, refurbished, smart
phones The online e-tailer, headquartered in Paris, launched in 2014. Awareness
of e-waste—the metals, chemicals, plastics and other elements in discarded electronics..."
 Cruciverbalists rejoice! Here is another
tech-related crossword puzzle to try your technical prowess. Unlike the weekly
RF Cafe crossword puzzle that contains only engineering, science, mathematics and
other tech words, this one from Electronics World does have a few unrelated
words. The big difference between making crosswords then and now is Mrs. Le Fevre
had to construct the grid of words manually, whereas I just create a huge file of
words and definitions, draw the grid outline, and then click a button to have software
put it all together. I'm guessing it took a couple hours to make this puzzle...
 Anatech Microwave Company offers the industry's
largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military, commercial,
aerospace and defense, and industrial applications up to 40 GHz. In their July
Product Update, Anatech has introduced three new power dividers, all having N connectors
(others available): An 8−way resistive power divider for DC−4.0 GHz, a 4−way
power divider for 2−18 GHz, and a 2−way power divider for 1−4 GHz. Custom
RF power directional coupler designs can be designed and produced when a standard
cannot be found, or the requirements are such that a custom approach is necessary.
 Thermex-Thermatron Systems, a major designer
and maker of RF and microwave welder and
sealer systems, wrote to request a listing on the
Manufacturing Equipment vendor page. Their RF and microwave
heating systems are ideal for medical manufacturing process such as sealing blood
and IV bags, cuffs, air and water mattresses. Thermex-Thermatron can custom design
and engineer an RF welder or sealer system to meet even the most complex specification.
Dedicated RF or microwave units available to test a wide variety of materials and
processes at little or no cost to you, to evaluate your product's suitability for
microwave or RF welding/sealing.
 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 (FR-4, Rogers, flexible, rigid), Geographical
location (U.S., China), kinds of services (manufacturing, fabrication, assembly,
prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
Thursday 23
 These "Radio
Term Illustrated" comics from vintage Radio-Craft magazines are some
of my favorite tech-themed comics. Most were drawn by Frank Beaven in response to
suggestions / requests by magazine readers. The one here from page 80 entitled "Crystal
Gazing" was done by Franklin Folger. If you didn't know that it appeared in a 1947
edition, you might assume it depicts a Steam Punk themed LCD computer monitor mounted
atop a Morse code straight key, but of course it is not. At the time, cathode ray
tubes (CRTs) were the only form of video display, and while small like the one in
the drawing (and round, unlike the drawing), they were far from flat. Little did
the artist suspect that his "Crystal Gazing" idea meant to imply a type of mystic's
medium for seeing...
 Benjamin Franklin is famous for his kite-flying
experiment whereby he 'discovered' not electricity (as many people believe), but
that
lightning is a form of electricity (most people thought it was a jet of gas).
A lesser known fact about Mr. Franklin is that he invented the lightning rod
after realizing the electrical nature of lightning. His understanding of electric
fields facilitated an implementation whereby hefty iron cabling interconnected a
tall, pointed rod installed at the tallest point on a building and a spike driven
into the ground. Lightning typically strikes the object that is the shortest distance
(in terms of electrical field strength) from it because the discharge can begin
at the lowest voltage. The presence of the grounded lightning rod above the highest
point on a structure effectively brings that point all the way down to ground level...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers"
Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's"
design has been ripped off by other people and used on their products, so please
be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per
item - Cafe Press gets the rest of your purchase price. These would make excellent
gifts for husbands, wives, kids, significant others, and for handing out at company
events or as rewards for excellent service. It's a great way to help support RF
Cafe. Thanks...
 "A new method could help pave the way for
widespread commercial availability of
flexible electronics. In the future, scientists imagine that the mobile devices
we use every day will be flexible, not rigid. However, in order to achieve this
long-term vision, researchers must develop stable flexible electronic components,
many of which will be comprised of thin films that are currently in development.
One drawback to these thin films is that they tend to crack when bent or folded
repeatedly, which has led scientists from Daegu Gyeongbuk Institute of Science and
Technology (DGIST) in South Korea to design a potential solution to this problem..."
 Kenneth Wyatt, a consulting engineer, has
a very useful article on the EDN website entitled, "Kit
for Testing Wireless and IoT Antennas," which features Copper Mountain Technologies'
IoTest
Antenna Testing Kit. FCC certification can be an expensive process, so
if you are developing a wireless product, a setup like this could save you a bundle
by allowing you to do an initial level of measurement prior to submission to a certification
lab or consultant. Mr. Wyatt begins, "In recent years, many of my clients have been
developing products that incorporate wireless and cellular communications into IoT
products. I've also been partnering with a local CTIA-approved wireless test lab,
BluFlux in Louisville, Colorado, to help mitigate various EMC issues. In working
with BluFlux, the major issue seemed to be self-generated EMI affecting the cellular
LTE and GPS receiver sensitivity..."
 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.
Wednesday 22
 Prior to seeing this new tidbit in a 1976
issue of QST magazine, I had no idea that the wife of Peanuts comic strip
creator Charles Schulz was an airplane pilot - and that is with having been a huge
Peanuts fan for decades. Other than one of Snoopy's alter egos being that of a World
War I flying ace, there is no other theme of airplanes in the strip, although
according to this article, there was a 1975 Sunday comic strip with Peppermint Patty
and Marcie flying atop Snoopy's doghouse, from California to Michigan. The Straits
Area Radio Club (W8GQN) provided communications for the Powder Puff
Derby, aka the Women's Air Derby, race in which Mrs. Jean Clyde Schulz
took part in 1970, 1971, and 1975. It was a very long course - more than 2,000 miles
as the crow flies...
 Triad RF Systems, an industry-leading provider
of stratospheric communications platforms first called on TRIAD, is proud to announce
aggressive revenue growth and a record 1st half of the year. We are achieving record-setting
performance driven by our strong reputation for developing fully-integrated and
optimized radios that deliver some of the highest data-rates and longest range ISR
wireless links for Unmanned Land, Sea, and Air Systems. We expect to continue to
deliver increases for 2020, driven by the continued acceptance of our products in
a growing number of defense programs. Financial & Program Highlights: First-half
revenue grew 45% over last year and our bookings growth was 126% year to date .Our
participation in critical long-distance unmanned aerial vehicle (UAV) systems programs...
 "The Defense Innovation Unit has awarded
Sierra Nevada Corporation a contract to build an orbital laboratory that would serve
as a kind of unmanned space station, the company announced July 14. The
unmanned orbital outpost will be placed in low Earth orbit to be used for experiments
and demonstrations. The autonomous, free flying vehicle will be able to host payloads
and support space assembly and manufacturing, microgravity experimentation, logistics,
training, testing and evaluations. Under the contract, Sierra Nevada Corporation
will repurpose their Shooting Star transport vehicle into a scalable, autonomous
space station that can be used for experiments and demonstrations. The Shooting
Star vehicle is a 16-foot attachment..."
 The big graphic with Figures 1 through 17
reminds me of the kinds of study sheets I used to make when cramming for exams in
my college circuits courses. Did I ever tell you about the wise guy instructor I
had for my first Circuits class at the University of Vermont? Anyway, this article
provides an introductory level treatment of using
negative feedback in amplifier circuits. Lots of illustration and formulas are
included. Frequencies are at baseband, so you won't learn any secrets for high frequency
amplifier stabilization, but then even RF and microwave circuits eventually need
to convert down to baseband at some point for sampling or for use as audio or video...
 Withwave announces a line of
High Performance Cable Assemblies with 0.047" cable diameter. Flexible, semi−rigid,
and & semi−flexible cable types are perfect for various kinds of interconnection
solutions such as high speed testing, short range, and telecommunication applications.
Frequency ranges include DC to 26.5 GHz, 40 GHz, 50 GHz, and 67 GHz.
Standard and custom cable options are available with connector types such as SMA,
2.92 mm, SMPM, 2.4 mm, and 1.85 mm...
 Joe Cahak, owner of Sunshine Design Engineering
Services in Ramona, California, has written a white paper entitled, "Measuring
Semiconductor Device Input Parameters with Vector Analysis." This article covers
a recent test experience that utilized some thinking about the test fixture, the
bias requirements and the device mounting and special calibration offsets needed
to de-embed the test fixture response from the device response within the test fixture.
The device also had to have bias on several ports simultaneously. We had to establish
a "reference plane" within the fixture, from which we can use the Vector Network
Analyzer's Port Extension or Phase Offset to dial out the distance from our 1 port
calibration reference plane to the point of short reference within the fixture.
With this phase offset compensation we can then measure...
 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. The company is
a leader in development and production of the films required for these type of RF/microwave
components. Please check out Res-Net Microwave's website to see how they can help
with your current project.
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