This is the eighth and final installment
on a "Microwaves" series of articles in Radio-Electronics magazine by author
C.W. Palmer. Each part is a stand-alone tutorial that does not rely on previous
parts to be useful. Unlike most of the preceding articles that dealt in one way
or another with waveguide, this final one concerns "receiving
and transmitting antennas for microwave communication." It touches lightly on
various types of antennas, field patterns, impedance matching, and applications.
If you've been around for a while, you've likely seen it all before, but there are
some nice photos of antennas designed and deployed by Bell Telephone Laboratories
for their nationwide microwave telephone relay network. Bell Labs has done a lot
of ground-breaking research in all aspects of communications technology...
"Designing semiconductor circuits hand-in-hand
microfluidic cooling systems could mean huge boosts in efficiency. The heat
generated by today's densely-packed electronics is a costly resource drain. To keep
systems at the right temperature for optimal computational performance, data center
cooling in the U.S. consumes the as much energy and water as all the residents of
the city of Philadelphia. Now, by integrating liquid cooling channels directly into
semiconductor chips, researchers hope to reduce that drain at least in power electronics
devices, making them smaller, cheaper and less energy-intensive. Traditionally,
the electronics and the heat management system are designed and made separately,
says Elison Matioli, an electrical engineering professor at École Polytechnique
Fédérale de Lausanne in Switzerland. That introduces a fundamental obstacle..."
Kenneth Wyatt has a good article on the EDN
website entitled, "Quickly
Assess Relative Coax-Cable-Shielding Quality." It begins: "Testing most products
for radiated emissions usually requires all I/O and power cables to be attached
to the equipment under test (EUT) and spread out in accordance with the specific
product standard. In many cases, we test engineers simply grab the nearest cables
and hope for the best during the compliance test. Unfortunately, poor-quality cables
can lead to emissions failures due to poor shielding or poor shield termination
(via 'pigtails') to the connectors. In an earlier article, I related the issue of
HDMI cable radiation due to shield pigtails. I also graphically demonstrate why
cable shield pigtails lead to radiated emissions in the video. In addition to the
shield pigtail issue, coax cables..."
WWV is the oldest continuously-operating
radio station in the U.S. since first going on the air from Washington, D.C. in
May 1920. It moved around an area near D.C. for a few years before being relocated
to its current location in Boulder, Colorado, in 1966. WWVB, another time standard
transmitter, had already been established in Boulder a few years earlier. Sister
station WWVH is located in Hawaii. The National Bureau of Standards (NBS) was renamed
National Institute of Standards and Technology (NIST) in 1988, nearly a century
after its inception in 1890. Having grown up not too far from Beltsville, Maryland,
I remember driving by their main campus when the NBS sign was still on the lawn.
The decision to change the name never did make sense, but then most of what government
bureaucrats do perplex me...
In response to an article about the ongoing Wuhan
Flu serum development programs, here is one of the cleverest online forum posts
I've ever seen: "This might surprise many of you, but I volunteered for the
vaccine trials for Covid-19. The vaccine is the one that was created in Russia.
I received my first shot yesterday and I'm excited because it seems completely safe,
with иo side effects whatsoeveя, and I feel sκ χoρoshό я чувствую себя немного
странно и я думаю, что вытащил ослиные уши." Plug the Ruskie part into a
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
Little known to most people (including moi
until recently), DeForest Training School was started by DeVry University's founder
Herman A. DeVry. DeVry and DeForest were DeGood DeFriends, leading DeVry to name
his electronics school after DeForest. It was re-named DeVry Technical Institute
in 1953. Research at DeForest Training School produced one of the first
RF / microwave food baking "ovens." The prototype reported in this 1951
Radio & Television News magazine article was not at all like modern microwave
ovens. There was no enclosure into which baking bowls, pans, and dishes can be inserted.
Rather, electrodes were arranged at the perimeters of the special pan that in this
demonstration contained cake batter. It was adapted from a process originally developed
for RF induction heating of industrial materials...
Electro-Photonics is a global supplier of
RF & Microwave components.
Their products include SMT hybrid and directional couplers, wire bondable passive
components, mounting tabs, filters, transmission lines, and very useful test boards
for evaluating components (spiral inductors, single-layer capacitors). The Electro-Photonics
team can support your small R&D design requirements with RF & Microwave
test fixtures and save you valuable design and characterization time. Please take
a moment to visit Electro-Photonics' website and see how your project might benefit.
"Satellite and spacecraft system designers
have a few different options when selecting field programmable gate arrays (FPGA)
semiconductors. One FPGA option is commercial off-the-shelf (COTS) components that
reduce component unit cost and lead time, but they are generally not reliable enough,
must be up-screened (which increases cost and engineering resources), and require
soft and hard Triple Modular Redundancy (TMR) to
mitigate radiation effects in space. In missions where failure is not an option,
designers typically choose higher-cost FPGAs that are radiation-hardened by design
(RHBD). These are already screened and qualified to Qualified Manufacturers List
(QML) Class Q and V standards..."
with Harbaugh" was a regular comic feature in Popular Electronics magazine
in the 1960s. Creator Dave Harbaugh chose topics ranging from husband-wife relationships
where the husband is a technophile of some sort and the wife either purposely or
unknowingly challenges his efforts to participate in his hobby, to contemporary
(at the time) subjects such as this month's treatment of biocells. Like solid state
electronics back in the day, bioengineering was a mysterious field few understood.
It received a great deal of attention by comedians and sci-fi film makers who got
a kick out of scaring people over the possibility of an alien contamination (a la
"The Andromeda Strain") or some secret government laboratory brewing up a deadly
Anatech Electronics 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. One each new
cavity-type duplexer and triplexer have been introduced. The AD1542-1643D296
is an Inmarsat duplexer with 1524-1560 MHz and 1626.5-1660.5 MHz passbands,
and the AD1800-2072-2250TR293 is a triplexer with 2025-2120 MHz, 2200-2230 MHz,
and 1750-1850 MHz. Passband insertion loos is >15 dB on all, and insertion
loss is <1 dB. Custom RF power directional coupler designs can be designed
and produced when a standard...
On September 29th beginning at Noon EDT, Cadence
| AWR will be presenting a free webinar entitled
NCSU Rabbit Radar - Design, Simulate & Build Your Own Radar at Home. "In
this webinar, Dr. Ricketts describes how to design, simulate, and build a 2.4GHz
frequency modulated continuous wave (FMCW) radar at home or in a lab. The webinar
begins with a short theory session followed by an explanation of the key components
of an FMCW radar, which include a mixer, power amplifier, coupler, low noise amplifier,
and filters. The components will use transmission line structures that attendees
NorthEast RF's comprehensive
services include linear | circular polarized antenna measurements and OTA cellular
device pre-compliance. Up to 18" diameter and <10 kg weight. Antennas can be
rapidly evaluated and optimized using our fast near field spherical system. Test
results supplied in data file with pattern viewer software. A picture of the test
configuration is included to help aligned axis. Our selection of human head and
hand phantoms are ideal for verification of body worn devices. Turnaround time is
Use of the word "modern" in titles of books
and magazine articles has always bothered me because of how quickly the referenced
topic becomes obsolete. It is only "modern" for a relatively short period of time.
In 1951 when this article appeared in Radio & Television News magazine,
germanium was the dominant semiconductor in use for
diodes and transistors. They could be used in small signal circuits of up to
about 500 MHz. That meant they could easily replace vacuum tubes in AM and
FM radios, and at least the IF and baseband sections of TVs. You might think that
would have represented a big component cost savings, but semiconductors were much
more expensive than vacuum tubes at the time. Still, the power savings, size reduction,
and higher reliability made the circuit changes worthwhile...
"A team of researchers at HRL laboratories,
led by Principal Investigator Dr. Jeong-Sun Moon, is developing the next generation
Gallium Nitride (GaN) transistors that will have a dramatic effect on electronic
components that amplify electromagnetic signals for communications, radar, and 5G
wireless networks. The ultra-linear monolithic microwave integrated circuit (MMIC)
amplifiers that utilize these high-speed GaN transistors can see greatly improved
linearity, noise reduction, and reduced power consumption. Moon's team has successfully
met and exceeded the performance metrics defined by the Dynamic Range-enhanced Electronics
and Materials (DREaM) program, a DARPA effort to improve dynamic range in millimeter-wave..."
Innovative Power Products (IPP), a company
with over 35 years of experience designing and manufacturing RF and microwave passive
components, wants to immediately fill an opening for an
RF/Microwave Design Engineer. The position requires demonstrated success in
the design and test of wide band, high power RF and microwave passive components.
Candidate to be familiar with linear and full-wave EM simulators. Responsibilities
include design, simulation, engineering document release, and prototype test of
new products. He/she will communicate with customers, travel as required to visit
customers or vendors, collaborate with Design and Drafting to satisfy customer requirements.
Train and support technicians on S-parameters, test procedures, troubleshooting,
and documentation of product...
Instrument Landing Systems (ILS) has been around since the early 1930s, as made
apparent by this article in Short Wave Craft magazine. Frequencies, circuits,
and infrastructure equipment have evolved over the years, but fundamentally, landing
an aircraft (airplane, helicopter, dirigible) under 'blind' flying conditions has
not changed. Two precision beams - one in elevation and one in azimuth - broadcast
by ground-based installations are detected by airborne receivers and relative positions
are displayed for the pilot's use in navigation. ILS does not help the pilot fly
the aircraft; it only leads him to the runway threshold. In the past couple decades,
space-based Global Positioning System (GPS) equipment has increasingly been used
to replace ground-based microwave systems...
Teledyne e2v HiRel, part of the Teledyne
Defense Electronics Group, today announced the latest addition to its rapidly expanding
line of RF solutions, a new
RF MMIC Frequency Doubler. Launching Teledyne e2v HiRel's new Frequency Multiplier
product line, this Active Doubler, TDFM001000, is designed for high reliability
signal chain applications in Space. It is particularly well-suited specifically
for satellite transponders, transmit/receive modules, microwave-based communications,
millimeter-wave point-to-point radio, and related processes. The TDFM001000 is a
7.5-25.0 / 15.0-50.0 GHz single ended input (no external balun required) GaAs
The October issue of IEEE's Spectrum magazine
ran an article entitled, "Let
a Thousand Analog Oscillators Sing." It reports on Sam Battle's "KiloDrone"
DIY project consisting of 1,000 analog reverse-avalanche oscillators, each built
with a transistor, capacitor, and resistor. A singe opamp isolates and amplifies
the output of each unit. In his video Mr. Battle explains the project, runs
through the tune-up procedure, and exhibits the final result. According to the story,
only 1.2 A is used from a 12 V DC supply for the entire setup. There are
10 independently tuned oscillators on each rack-mountable panel. A
printed PCB panel (not including components) can be purchased for $52.
Bob Pease would have loved
this guy whose motivation is summarized thusly: "I like the tangibility of analog.
I hate working on computers. I just can't stand looking at screens. I like standing
up and moving around and making things in a physical world."
Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave
connectors, between-series adapters, RF components and filters for wireless
service providers including non-magnetic connectors for quantum computing and MRI
equipments etc. ISOTEC's product line includes low-PIM RF connectors components
such as power dividers and directional couplers. Off-the-shelf and customized products
up to 40 GHz and our low-PIM products can meet -160 dBc with 2 tones and
20 W test. Quick prototyping, advanced in-house testing and high-performance.
Designs that are cost effective practical and repeatable.
When I saw the images in this "Electron
Shadows Map Force Fields" article from a 1949 issue of Radio-Electronics
magazine, the first thing I though of was how as kids back in the 1960s we would
hold magnets against the front of the television cathode ray tube (CRT) to see how
they distorted the picture. If I still had a CRT TV or computer monitor around,
I'd take some photos of it for the sake of those who have never seen what happens.
The difference between that and the images formed here is that the professionals
inserted the object of interest directly in the electron beam, between the cathode
and the fluorescent glass grid. As with the images in the article, magnets of various
shapes created unique responses. If you drag the magnet across the face of the CRT...
"The evolution of military electronics is
marked by an endless series of
measures and countermeasures. The enemy meets an enhancement in U.S. fighter
jet technology with an improvement in its missile-guidance capabilities, forcing
additional innovations from the U.S. The never-ending effort to enhance the effectiveness
of military technology and protect the warfighter on the battlefield propels forward
innovation in the industry. Today, there's a battle underway that is dramatically
expanding the frequency ranges used by the military for communications - soldier-to-soldier,
soldier-to-satellite, aircraft-to-ground, missile-to-target, and more. Whereas military
electronics used to operate in a narrow band of frequencies, today, military design
engineers must protect equipment from damaging signal interference and enemy..."
Cafe visitor Kire P. let me know about a really nice website with lots of information
about EMC (electromagnetic compatibility) and governing industry standards. The
Academy of EMC is a non-profit
based in Switzerland. It has a large variety of downloadable documents covering
(PCBs, cables, enclosures, etc.) for how to assure your products will pass testing
global, EU, U.S. and other
EMC standards, including
compliance marks from
countries and groups. An educational area contains suggestions for books and other
resources. There are also half a dozen articles on the Blog page. Keep in mind
when reviewing any standard that you must go to the source for the most up-to-date
version. Failure to do so can be quite expensive.
The Evaluation Engineering website has a
good article entitled, "RF/Microwave
Switching Adds Flexibility to Diverse Applications" that runs through some state
of the art hardware available for R&D and production test setups. It pitches
products from multiple vendors, so it is not just an infomercial. "Engineers in
industries ranging from telecommunications to military / aerospace need high-performance
RF/microwave switching as part of their test setups. Consequently, vendors are offering
products ranging from individual switches to complete switching systems to meet
customer demand. This report describes the latest available RF / microwave switching
products and the applications they serve..."
A while back I was using the familiar
analogy that relates water pressure, hose diameter, and flow rate to electrical
voltage, resistance, and current, respectively, in an explanation to my daughter
regarding why the water characteristics in her house changed after the well supply
pipe and indoor plumbing changed. The cause, I proposed, was due to an increased
distance between well and house, and the use of the plastic PEX tubing with a smaller
inside diameter than the old copper pipe, respectively. The submersible pump and
holding tank still supply the same 50 psi as before, but since that pressure
now has to force the water through a path inside the house with more resistance
to water flow, the delivery rate to fixtures is now lower. When I hold the contacts
closed on the pump control relay, the most I can get is about 55 psi. Raising
the pressure will require replacing...
Fall has finally arrived! The
equinox occurs today, September 22, 2020, at 9:30 A.M. EDT (13:30 UTC). The
equinox occurs at the same moment worldwide, regardless of local time zone. The
word "equinox" comes from Latin "aequus,"
meaning "equal," and the Latin "nox,"
meaning "night." It marks the moment the sun crosses the celestial equator, which
is coincident with Earth's equatorial plane, as it descends from north to south
(south to north transition marks the vernal equinox). I've never seen this
offered anywhere, but why not "equal day" rather than "equal night?" "Pernox"
means day, which would give us equipernox rather than equinox.
solstice (solstice = sol + stitium ≈ sun stands still) occurs December
21, 5:02 A.M. EST.
Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
September 27th's custom
Engineering themed crossword puzzle contains only only words from my custom-created
lexicon related to engineering, science, mathematics, chemistry, physics, astronomy,
etc. (1,000s of them). 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. The technically inclined cruciverbalists amongst us will appreciate
PCBONLINE, a global high-end PCB manufacturer
servicing electronics manufacturing (EMS) customers in defense, aerospace, medical,
and other high-end industries, has posted a technical blog entitled, "Comprehensive
Guide to SMT Stencils." It answers questions about what are SMT (Surface Mount
Technology) and SMT stencils and what are they used for, where do you get SMT stencils
for PCB assembly, what are the different types of SMT stencils, and how do you use
SMT stencils? SMT (Surface Mount Technology) stencils are very important for PCB
designing and manufacturing. If you can't decide which type of SMT stencil to go
for and you need a detailed guide for this topic, then you're in the right place.
This article will focus on every aspect of PCB stencils and by the time you reach
Comics June 1951 Radio-Electronics
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 13,000 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. If you need your company news to be seen, RF Cafe is the
place to be. Advertising begins at $40/month.
RF Cascade Workbook 2018 is the next phase in the evolution
of RF Cafe's long-running series, RF Cascade Workbook. Chances are you
have never used a spreadsheet quite like this. It is a full-featured RF system cascade
parameter and frequency planner that includes filters and mixers for a mere $45.
Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and
the format is entirely customizable. It is significantly easier and faster than
using a multi-thousand dollar simulator when a high level system analysis is all
that is needed. An intro video takes you through the main features...
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...
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
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
at no charge. 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
"Comparing the relatively simple Fraunhofer
or 'far field' approximation commonly used in radar and high-powered microwave systems
with the more complex near field propagation model based on the field equivalence
principle demonstrates which approach achieves reasonable modeling fidelity with
minimal compute power. Modeling and Simulation can be used to explore the design
trade space of directed energy weapons. M&S can be particularly helpful when
that trade space is influenced by a large number of parameters and when acquiring
field data to explore those parameters requires a large amount of resources. One
example involves the
Active Denial Technology system, a non-lethal, counter-personnel..."
"Graphene can be
sculptured by electron beams, according to researchers at Georgia Tech. Carbon
atoms can be added or subtracted - and in the case of graphene oxide, surface oxygen
can be used to remove carbon atoms with no additional chemicals. 'By timing and
tuning the energy of the electron beam, we can activate interaction of the beam
with oxygen in the graphene oxide to do etching, or interaction with hydrocarbons
on the surface to create carbon deposition,' said mechanical engineer Professor
Andrei Fedorov. 'With atomic-scale control, we can produce complicated..."
"As our lives become increasingly intertwined
with technology - whether supporting communication while working remotely or streaming
our favorite show - so too does our reliance on the data these devices create. Data
centers supporting these technology ecosystems produce a significant carbon footprint
- and consume 200 terawatt hours of energy each year, greater than the annual energy
consumption of Iran. To balance ecological concerns yet meet growing demand, advances
in microelectronic processors must be efficient and environmentally friendly. Northwestern
University materials scientists have developed new design principles that could
help spur development of future
quantum materials used to advance (IoT) devices and other resource-intensive
technologies while limiting ecological damage..."
"You can feel it on your laptop and mobile
phone. It's behind your refrigerator and office copy machine. While heat is desirable
for appliances like a coffee maker, it can jeopardize the reliability and safety
of electronic systems in other devices, causing premature failure at best and explosions
at worst. Active control of heat transport, as with thermal switches and thermal
diodes, is important for a range of applications in heating and cooling, energy
conversion, materials processing, and data storage. In practice,
thermal diodes are highly desirable thermal components for many engineering
applications because they allow energy systems to transfer heat to designated areas..."
"EPFL physicists propose a new path to
detect infrared radiation
with outstanding sensitivity, allowing detection of signals as low as that of a
single quantum of light. When using our webcam or cell phone camera, we experience
the tremendous capabilities of cheap and compact sensors developed in the past decades
for the visible region of the electromagnetic spectrum. On the contrary, detection
of lower frequency radiation not visible to the human eye (such as mid- and far-infrared
radiation) requires complex and costly equipment. Lack of a compact technology impedes
widespread access to sensors for the recognition of molecules and the imaging of
thermal radiation naturally emitted by our bodies. A new conceptual breakthrough
in this field may therefore..."
"Two DARPA-developed technologies - a novel
decision aid for mission commanders and a rapid software integration tool - played
a critical role in the recent Air Force demonstration of the Advanced Battle Management
System (ABMS). The Adapting
Cross-domain Kill-webs (ACK) program and the System-of-systems Technology Integration
Tool Chain for Heterogeneous Electronic Systems (STITCHES) were among a number of
technologies employed in the Aug. 31 - Sep. 4 ABMS on-ramp demonstration, which
involved attacks using live aircraft, ships, air defense batteries, and other assets.
ACK is developing a decision aid for mission commanders to assist them with rapidly
identifying and selecting options for tasking - and re-tasking - assets within and
across organizational boundaries. Specifically, ACK assists users with selecting
European Space Agency Develops a Mesh Reflector for Shaped Radio Beams
Electron Hole, Meet Your Fractional Cousin
Smallest thermoelectric cooler, by 10,000 times