See Page 1 |
2 |
3 |
4 of the February 2019 homepage archives. Friday 1
 Freon has for so long been demonized as a
destroyer of the ozone layer and has so thoroughly disappeared from consumer grade
products that I had forgotten that many moons ago I and others used it on a regular
basis for
cleaning electronics assemblies. Freon 12, methyl chloroform
(aka 1,1,1-Trichloroethane ), and methyl ethyl keytone (MEK, aka butanone) were
all very common cleaners for removing contaminants prior to soldering and for removing
flux after soldering in the days of 60/40 Sn/Pb solder and RMA (rosin, mildly activated)
flux. Call me a heretic of the green movement, but I still use 60/40 rosin core
solder for all my electronics work. In fact, I just ordered a new 1-pound roll of
it from Kester, along with a bottle of liquid RMA flux. I have changed over to Pb-free
solder for plumbing, although I'm still a bit nervous when using it - especially
when soldering into installed pipes that have been plugged with a piece of bread
to (hopefully) keep the area dry long enough to sweat a good joint...
At VidaRF, the phrase 'Providing Simple Solutions for Complex Connections' is
more than just a slogan – it's a mindset, a mission, and a driving force behind
everything we do. Their pledge is to design and distribute high performance, cost
effective
RF Microwave products to fit each customer's unique applications.
Please visit VidaRF today to see how their lines of Attenuators & Terminations,
Directional Couplers, Power Dividers, Coaxial Connectors, and Circulator & Isolators
can be of use to your project. "When the standard just will not do, VidaRF has the
solution for you!"...
 Here is another of the "Electronic Sticklers" challenges from Popular Electronics
magazine - good for ratcheting down at the end of the week. These are fairly basic
circuit analysis problems that often can be solved by inspection, but sometimes
a pencil and paper are necessary. Re-drawing the circuit in a different configuration
to make the connections more obvious often helps when solving total resistance,
capacitance, inductance, etc., as in question #1. In this case, though, you need
to be able to recognize a common configuration to be able to simplify the circuit;
otherwise, you'll be writing and solving mesh equations. #2 has a simple answer
and a more elaborate possibility. #3 and #4 are simple inspection problems...
 Empower RF is pleased to announce the release
of Model 1219, a single band
solid state GaN module delivering a minimum 30 W (40 W
typical) across its entire 0.6 to 6 GHz band. Empower RF is the first amplifier
manufacturer to cover this bandwidth with an affordable COTS product. The 1219 utilizes
50 V GaN on SiC transistors which have lower leakage currents and higher thermal
conductivity and is a more reliable technology than GaN on Si. An added benefit,
50 V devices require about half the input current as their 28 V counterparts
which reduces power supply cost, size, and weight. This compact class AB amplifier
is suitable for broadband mobile communications, jamming, and product test applications...
 Mssrs. Rick Gentile of MathWorks (MATLAB &
Simulink), Honglei Chen, and Marc Willerton have nice article on the Microwaves & RF
website titled, "Algorithms to Antenna: Calibration Techniques for Phased-Array Antennas."
This post discusses calibration for perturbed phased-array antennas, examining techniques
like pilot calibration and self-calibration. "When large phased-array antennas are
built, perturbations in amplitude, phase, element position, and antenna patterns
will invariably be present due to a range of factors. Perturbations can also arise
due to other factors, such as coupling, hardware aging, clock drifting, and environmental
effects. These perturbations may impact the performance of the system..."
Custom MMIC is a
fabless RF and microwave MMIC
designer entrusted by government and defense industry OEMs.
Custom and off-the-shelf products include
switches, phase shifters, attenuators, mixers and multipliers, and low noise, low
phase noise, and distributed amplifiers. From next-generation long range military
radar systems, to advanced aerospace and space-qualified satellite communications,
microwave signal chains are being pushed to new limits - and no one understands
this more than Custom MMIC. Please contact Custom MMIC today to see how they can
help your project...
 "Researchers at MIT have developed a
sub-terahertz-radiation receiving system that could help steer
driverless cars when traditional methods fail. Currently, autonomous vehicles traditionally,
use light-based image sensors that often struggle to see through blinding conditions,
such as fog. Sub-terahertz wavelengths, which are between microwave and infrared
radiation on the electromagnetic spectrum, can be detected through fog and dust
clouds with ease, whereas the infrared-based Lidar imaging systems used in autonomous
vehicles struggle. To detect objects, a sub-terahertz imaging system sends an initial
signal through a transmitter; a receiver then measures the absorption and reflection
of the rebounding..."
ERZIA serves critical aerospace and defense missions by designing and manufacturing
RF, microwave, and mm-wave amplifiers,
integrated assemblies operating from low frequencies up to 100 GHz, and by
providing high reliable satellite communications. The company was founded in 2002
to become a worldwide reference of advanced engineering, performance, reliability
and ruggedness. Their catalogue of standard amplifier modules comprises more than
100 different models, having also a high capacity of customization for amplifiers
and integrated assemblies. Some of products have space heritage and are used in
aerospace, commercial, military and scientific systems, having a wide range of final
applications...
Thursday 28
 There are probably few baseband and IF
delay lines these days that are constructed from a chain of inductor-capacitor
(LC) sections as described in this 1953 Radio-Electronics magazine article.
SAW and MEMS devices are the more likely choice for many reasons including cost,
weight, and volume savings. The preferred implementation of measured delays nowadays
would be in software after sampling with an analog-to-digital converter (ADC). There
are still applications for coaxial delay lines such as phase matching or adjustment
between system elements, and many companies offer custom designs with delay precision
in the tens of picoseconds. I once worked on part of a VHF/UFH transceiver unit
that used precise lengths of coax cable as part of a signal cancellation circuit
for enabling multiple radios to function in close proximity. I was not the designer...
 KP Performance Antennas, an Infinite Electronics
brand, and an industry-leading manufacturer of wireless network antennas, has unveiled
a brand new
900 MHz, 10 dBi, ±45° slant dual-polarized omni antenna
for use in outdoor fixed wireless applications. This new omni-directional antenna
from KP operates in the 824-928 MHz frequency range and provides uniform, 360°
coverage with minimal azimuth ripple and 10 dBi of gain. It supports any 900 MHz
access point radio (AP), including the popular Cambium® PMP450i™ radio for point-to-multipoint
installations. This new 900 MHz omni antenna has 15° elevation beamwidth and
is able to penetrate dense foliage with 900 MHz, dual ±45° slant polarization.
The antenna comes with robust mounting hardware...
 These two advertisements appeared in the
July 1935 edition of QST. Bliley Electric is still in business here in
Erie, Pennsylvania as
Bliley Technologies. They make crystals and frequency sources.
Gross Radio has been out of business for quite a while. I included it mainly to
illustrated how large radio transmitters used to be - these things were installed
in people's attics and basements back in the day. This particular model, the CB-100,
is a "100-Watt Radiophone & C.W. Transmitter completely housed in an entirely
enclosed floor rack of ingenious design." It operated in the 1.7, 3.5, 7 and 14
MHz bands. For comparison, iCOM makes a 1 kW power amplifier today covering
those bands...
 "Meta surfaces can be designed to steer sound
or electromagnetic waves in arbitrary directions, or act as beam splitters, according
a team from Aalto University in Finland and Duke University North Carolina.
'Existing solutions for controlling reflection of waves have low efficiency or difficult
implementation,' said Aalto researcher Dr Ana Díaz-Rubio. 'We solved both of those
problems. Not only did we figure out a way to design high efficient meta-surfaces,
we can also adapt the design for different functionalities. These meta-surfaces
are a versatile platform for arbitrary control of reflection.' The surfaces have
been dubbed meta-mirrors, and the key to creating them is applying new physics..."
 Copper Mountain Technologies (CMT), along
with Compass Technology Group, has a webinar titled "A New Method for Dielectric Property Measurements" coming up on
Thursday, February 28, at 11:00 am EST. Dr. Schultz, Chief Scientist at the Compass
Technology Group, is the presenter. Dielectric properties are important for design
of antenna and wireless technologies. As the internet of things, 5G, automotive
sensing, and other advanced technologies become more prevalent, product designers
and manufacturers require accurate material properties for ensuring their devices
operate as desired. This webinar will provide information about dielectric materials
measurements and introduces a new dielectric measurement method, called the epsilometer ...
Triad RF Systems designs and manufactures RF power amplifiers and systems. Triad RF Systems comprises three
partners (hence 'Triad') with over 40 years of accumulated
knowledge of what is required to design, manufacture, market, sell and service RF/Microwave
amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating
amplifiers are available, in formats including tower mount, benchtop, rack mount,
and chassis mount. "We view Triad more as a technology partner than a vendor for
our line-of-sight communications product line." Please check to see how they can
help your project...
Wednesday 27
 Albert Einstein declared and proved that
time is relative and depends on the observer's perspective. To someone sixty years
old, the year 1971 seems like it was just yesterday, but to people born a couple
decades ago, it seems like ancient history. Even so, I am taken by surprise when
I read a story from a 1971 issue of Popular Electronics that has produced
a list of "early computers" and it includes models like the ENIAC and Harvard
Mark I. Instinctively, the IBM XT, Apple II, and Packard Bell, and Compaq
lines of personal computers (PCs) come to mind. In 1971, there were no PCs. However,
if you compile a list of antique computers, then the aforementioned names apply.
This article does provide a nice recounting of the evolution of digital computers
from Charles Babbage's mechanical Difference Engine through those vacuum tube-based
electronic computers...
 A new e-learning module covering the NI AWR
Design Environment platform RF printed circuit board (PCB) layout import wizard
technology is now available on the NI AWR e-learning portal. This seven-part module,
running approximately one hour, trains users on how to use the
PCB layout import wizard for successful electromagnetic (EM) verification
within Microwave Office circuit design software. It covers verification flows and
layout file formats supported, and showcases a Zuken PCB design example through
material, port and mesh setup, as well as simulation...
 There is no such thing as too many introductory
articles on
operational amplifiers (opamps). Of course, when this story was
written for Electronics World back in 1967, opamps were relatively new to the scene.
Prior to the advent of opamps, circuit design for controllers, filter, comparators,
isolators, and just plain old amplification was much more involved. Opamps suddenly
allowed designers to not worry as much about biasing, variations in power supply
voltages, and other annoyances, and instead focus on function. Even from the very
beginning with the μa741 operational amplifier, the parameters came close to those
of an ideal device: infinite input impedance, zero output impedance, perfect isolation
between ports, and infinite bandwidth. OK, the bandwidth spec was more constrained
compared to the other three, but still, with frequencies...
 ConductRF is the brand name for Electronic
Assemblies Manufacturing, Inc.'s, complete range of RF interconnect products. ConductRF
products include solutions for both commercial and precision RF applications for
both RF cable assemblies and
connectors. Our manufacturing capabilities include solutions built at our ITAR
registered facility in Methuen as well as partner facilities in the U.S. and around
the world. ConductRF offers cost effective equivalent and improved RF solutions
to all major interconnect manufacturers, specializing in phase stability over temperature...
 "An
electromagnetic pulse (EMP) emitted by a nuclear weapon exploded
high above the United States could disable the electronic circuits of many devices
vital to military defense and modern living. These could include complicated weapon
systems as well as phones, laptops, credit cards and car computers. Also in trouble
might be home appliances, gas station pumps and bank accounts. Fortunately, military
equipment is designed to be immune to various levels of EMP, and the validity of
its designs - and some civilian designs as well - have been tested and improved
by a 'friendly' EMP generator installed in a recently renovated facility at Sandia
National Laboratories ..."
 Providing full solution service is our motto,
not just selling goods. RF & Connector Technology has persistently pursued a
management policy stressing quality assurance system and technological advancement.
From your very first contact, you will be supported by competent RF specialists;
all of them have several years of field experience in this industry allowing them
to suggest a fundamental solution and troubleshooting approach. Coaxial RF connectors,
cable assemblies, antennas, terminations, attenuators, couplers, dividers, and more.
Practically, we put priority on process inspection at each step of workflow as well
as during final inspection in order to actualize "Zero Defects..."
Tuesday 26
 Frequency hopping spread spectrum, first
proposed and patented by Hollywood actress Hedy Lamarr, relies on both transmitters
and receivers to precisely tune in a pseudorandom manner to a band of discrete frequencies
in a time-synchronized manner with each other. The faster an encoded signal hops
between frequencies, the more difficult it is for an unintended listener to decode
the message. Same goes for the number of discrete frequencies used in the spread
spectrum scheme. Modern computer programs and fast-tuning receiver systems can gather
huge amounts of information spread across a broad bandwidth and re-assemble it into
intelligible data, and if an unlimited amount of time was available to do so, just
about any message can be decoded...
 VidaRF, a manufacturer of high performance
RF and microwave high performance isolators, circulators, power dividers, couplers,
and other passive components, is proud to introduce VidaRF introduces
Power Dividers covering 698 MHz through 2.70 GHz for
all wireless applications from cellular through UMTS. Available in 2, 3, 4, 6 and
8-way with SMA, N, QMA or alternative connector configurations. VidaRF is focused
on being a solution provider by building to customer specs and offering zero days
lead time for custom parts through stock and ship program...
 This 1934 edition of Tower Radio
magazine was thrown in with a batch of vintage radio magazines I bought on eBay.
Most of the content pertains to entertainers of the day rather than with technical
issues. Reportedly, it was only sold at Woolworth's stores. Ironically, the number
of households with over-the-air (OTA) radio listeners today, at least as a percentage
of the population if not in absolute numbers, is probably about the same as in 1934
when commercial radio broadcasting was just getting a foothold. These days, many
- if not most - people listen to radio and podcasts via cellphone and/or Internet
streaming media than from over-the-air broadcasts, even while in their cars. Organizations
like the National Association of Broadcasters (NAB) are trying to change that, but
it's an uphill battle. I tune in to OTA when possible, but with my radio sitting
close to the computer with all the EMI it spews...
 A few years ago I posted a note about a technical
faux pas on an episode of Star Trek titled "Court Martial," where Captain Kirk makes
a comment ordering the ship's auditory sensors to be boosted "on the order of
1 to the 4th power," (14) in order to pick up heart
beats. RF Cafe visitor Sam M. just sent me a note offering a possible - and
plausible - explanation for the gaff. If you are a devoted Trekkie looking for a
response to your apostate friends when confronted over the scene, read on...
 QuinStar Technology, a California-based microwave
and millimeter-wave engineering company, will be exhibiting March 4-7 at the American
Physical Society March Meeting in Boston. They will be showcasing its cryogenic
product line, including a brand-new smaller housing. In addition, QuinStar is offering
the unique opportunity to schedule one-on-one time with a design engineer while
at the meeting. Appointments are available for March 5 and 6. QuinStar cryogenic
components are used in quantum computing, particle physics research, and radio astronomy.
They design and manufacture cryogenic isolators, circulators, and arrays onsite.
Because the performance demands for cryogenic components are ever-changing to meet
rapidly advancing technologies...
 Rohde & Schwarz develops, produces and
markets
test & measurement, information and communications technology.
Focus is on test and measurement, broadcast and media, cybersecurity, secure communications,
monitoring and network testing. Markets serviced are wireless, the automotive industry,
aerospace and defense, industrial electronics, research and education, broadcast
and media network operations, consumer electronics, cybersecurity for business and
governments, communications and security solutions for critical infrastructures
and the armed forces, reconnaissance equipment for homeland and external security,
and much more...
Monday 25
 Selecting the proper antenna for a particular
application can mean the difference between success and failure when any combination
of signal strength and/or signal interference is involved. Modern spread spectrum
technologies has eased the job a bit, but there are still instances when high gain
and/or directivity is necessary. You might be tempted to say that gain and directivity
are essentially the same thing, and to some extent that is true. However, in the
case of needing to minimize signal interference from surrounding sources, a
directional antenna might be utilized not due to a need for increased
desired signal strength but to reduce the power of undesired emitters. Such was
often the requirement for television and FM radio reception. After years of needing
to reorient the folded dipole antenna for my FM radio because...
 Saelig Company, Inc., announces the
Spectran XFR V5 PRO Real-Time Spectrum Analyzer - a portable,
rugged RF detection device designed to capture even the briefest signal transmissions.
Its rapid signal acquisition scans a 20 GHz bandwidth in less than 20 ms,
making it the world's fastest counter-surveillance receiver. The instrument's internal
GPS also indicates the precise location of the measured signals. Housed in a ruggedized,
i7-based Windows 10 laptop with a sunlight-readable 15.6" display and magnesium
alloy case, this analyzer is ready-to-go for covert outside field operations...
 America's first successful orbiting of a
satellite launch happened on February 1, 1958 with the launch of Explorer 1
atop a Juno 1 rocket. Our first attempted satellite launch was the Vanguard TV3,
on December 6, 1957, but it unfortunately succumbed to a failed booster rocket (it
rose only 4 feet off the launch pad). Russia had already launched its Sputnik 1
satellite on October 4, 1957, making it the very first manmade satellite to orbit
the earth - to the forever chagrin of U.S. scientists. Fortunately, advances occurred
rapidly for the U.S. space program after Explorer 1. In its first full decade
of existence, the
Goddard Space Flight Center, located in Greenbelt, Maryland, was responsible
for launching more than 100 different spacecraft...
 Once again, the crew at everythingRF will
be providing up-to-the-minute coverage of events at
GSMA Mobile World Congress (MWC), being held this year in Barcelona,
Spain, February 25 through 28. MWC2019 includes a world-class conference featuring
visionary keynotes and thought-provoking panel discussions; an exhibition with more
than 2,000 companies displaying the cutting-edge products and technologies that
define the future of mobile; the world's best opportunity for mobile industry networking;
and the annual Global Mobile Awards ceremony, which recognizes the most innovative
mobile solutions and initiatives from around the world. It's a tough assignment,
but somebody has to do it ;-)...
 "Lasers are widely used in household appliances,
medicine, industry, telecommunications and more. Several years ago, scientists introduced
nanolasers. Their design is similar to that of the conventional
semiconductor lasers based on heterostructures in common use for several decades.
The difference is that the cavities of nanolasers are exceedingly small, on the
order of the wavelength of the light they emit. Since they mostly generate visible
and infrared light, the size is on the order of one millionth of a meter. Nanolasers
have unique properties remarkably different from those of macroscopic lasers. However,
it is almost impossible to determine at what current the output radiation of the
nanolaser becomes coherent..."
 Please
take a few moments to visit the
everythingRF website to see how they can assist you with your
project. everythingRF is a product discovery platform for RF and microwave products
and services. They currently have 227,460 products from more than 1210 companies
across 285 categories in their database and enable engineers to search for them
using their customized parametric search tool. Amplifiers, test equipment, power
couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you...
Sunday 24
 Beginning in 2000, I have created hundreds
of custom
technology-themed crossword puzzles for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out
on whether or not this type of mental challenge helps keep your gray matter from
atrophying in old age, but it certainly helps maintain your vocabulary and cognitive
skills at all ages. A database of thousands of words has been built up over the
years and contains only clues and terms associated with engineering, science, physical,
astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge
of a numbnut soap opera star or the name of some obscure village in the Andes mountains.
You might, however, encounter the name of a movie start like Hedy Lamarr or a geographical
location like Tunguska, Russia, for reasons which, if you don't already know, might
surprise you...
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.
About RF Cafe.
Homepage Archive Pages
2025:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2024:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2023:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2022:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2021:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2020:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2019:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2018:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2017:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2016:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2015:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2014:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2013:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2012:
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 (no archives before 2012)
- Christmas-themed
items
|
