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.
3 of the December 2017 homepage archives.
Luminescent Paint Makes LiFi Networks
"'Smart paint' containing fluorescent and phosphorescent
pigments could extend the possibilities of proposed
LiFi networks, report a team led by K S Narayan at the Jawaharlal
Nehru Centre for Advanced Scientific Research in Bengaluru, India. The researchers analysed
the effect of nearby luminescent surfaces on the noise characteristics of visible light
communication system (VLC) signals, and found that secondary emission could limit bandwidth
locally by overwhelming receivers ..."
Radar Sees Through Walls by Seeking Symmetry
"Through-wall-imaging (TWI) technologies do just what their name suggests:
Allow users to 'see' through walls. Most radar offerings, however, call for a range of
frequencies - a broad capability that increases costs. Current TWI systems also require
advanced knowledge of the wall's materials; software frequently predicts how a given
barrier will affect the scanning wave, separating echoes and distortions from the solid
objects being sought. Using a narrow band of microwave frequencies, researchers at Duke
Mechanical filters of the type described in this
1969 Electronics World article are yet another example of the genius of some
people. They are actually a form of electromechanical device in that the applied electrical
signals are first converted into mechanical signals, followed by resonant mechanical
elements that discriminate according to frequency, and finally a conversion back to an
electrical signal is made. It is fundamentally the same principal as a crystal, SAW,
or BAW filter, albeit each with distinctly different methods and topologies. Mr. Donovan
Southworth, of Collins Radio, presents the basics of mechanical filters in this brief
write-up. There is an excellent article on mechanical filters ...
Reindeer Really Do Know How to Fly!
For the past
many years, videos have been posted that confirm to all the
out there what "The Christmas Song" songwriters Bob Wells and Mel Tormé (popularized
by Nat King Cole) asserted. This story qualifies as a high tech subject due to the FHSS
/ DSSS techniques in the ISM band radio systems, and brushless motors using LiPo batteries.
Are Print Magazines Less Important to
Microwaves & RF Technical Editor Chris
DeMartino has a piece in the 12/17 issue that asks the question, "Are Print Magazines Less Important to Engineers?" He makes the point
that increasingly higher percentages of people get most or all of their information online.
He also states that many engineers still appreciate a printed page, especially for long
articles or anything that should be filed away for later reference. I totally agree,
personally preferring a printed magazine to online since I typically scan them cover
to cover. Since he, like others, prints a hard copy of some online pages, it shows totally
paperless is not yet a reality. However, if you have the option to print just a page
or two or waste an entire magazine of ink, paper, and delivery service, the former seems
less wasteful much more eco-friendly ...
Adding a Bit of Artificiality Makes
Graphene Real for Electronics
"In the last few years, a new form of graphene
has garnered increasing interest. Dubbed 'artificial graphene,' this latest addition to the 2D landscape is
not formed from a single atomic layer of graphite. Instead it is synthesized from other
materials to have the same honeycomb lattice molecular structure as graphene, but modified
to have specific electronic properties. Now a team of researchers from Columbia University
and colleagues from Princeton and Purdue Universities along with those from the Instituto
Italiano di Tecnologia in Italy has taken the next step ..."
The introduction of low cost, small-footprint
ceramic filters were unquestionably a boon to efforts at reduction in end-product
package size and manufacturing cost. Very good Q and selectivity, no tuning required,
and good temperature stability made them perfect for use as IF filters in broadcast radio
receivers, at 10.7 MHz (FM) and 455 kHz (AM). They became available for commercial
use around 1960. This publically available paper published in 2000 from the IEEE provides
some historical perspective to ceramic filters: The History of Ceramic Filters,
by Satoru Fujishima. The Clevite Corporation, for which this ...
Mini-Circuits December News & Product Highlights
announces the availability of four new devices in its lineup of RF and microwave components.
Included are a precision SMA connector gauge kit, a 2.4 mm (female to female) adapter
covering DC to 50 GHz for industry-leading value, a miniature lumped element lowpass
filter that passes DC to 83 MHz with sharp rejection , and a tiny LTCC lowpass filter
that passes DC to 8440 MHz ...
Tower Companies to Benefit from Tax
Reform, Emergence of IoT
"Tax reform and the emergence of the IoT are two
reasons for tower companies to be grateful this holiday season. Cutting taxes has become
a top priority for Congress under Donald Trump’s administration, and wireless carriers
- like companies in countless other industries - are very much in favor of the move.
AT&T CFO John Stephens said recently that his company is 'optimistic about tax reforms,'
and T-Mobile CFO Braxton Carter said last week that T-Mobile likely wouldn’t be in a
position to pay cash taxes for roughly the next ..."
Triad RF Systems Intros a 1.3-1.4 GHz, 20 W Dual Bidirectional
Triad RF shipped our latest Dual BDA,
TTRM1081D. This unit is compatible with all military and commercial
radios and provides over 20 W of linear RF power across 1.3 to 1.4 GHz. Made
specifically for multi-in-multi-out (MIMO) radios, providing 2 radio ports and 2 antenna
ports, each providing 5 W of 64 QAM power and over 20 W peak power. The BDA
operates off a single +28 V supply and provides 25 dB of TX gain and 11 dB
of RX gain in both channels. This class AB LDMOS module is designed for both military
and commercial applications ...
National's Company - Merry Christmas and Happy New Year
This full-page advertisement by the National's
Company (not sure why the apostrophe was included) wished a Merry Christmas and a Happy
New Year to QST magazine readers. National manufactured a lot of amateur radio equipment
at the time, along with some commercial gear for mobile and home radio. Evidently no
fewer than 41 licensed Hams worked at the company since their names are listed. That
helps to explain the huge popularity of National's products in the hobby. National Company
went to the expense of having a
1940 Christmas Seals stamp affixed in the upper left corner of the page. I was surprised
to see the stamp and at first thought maybe the previous magazine ...
Signal Reception with Antenna Diversity
w/Multiple High Speed DACs
"In modern wireless systems, numerous
diversity techniques are used to maximize data throughput and improve
transmission reliability. Time, frequency and code diversity techniques are used to transmit
signals to multiple users simultaneously and to maximize the amount of data transmitted.
By transmitting at different times, on different frequencies, or with different binary
sequences known as Gold codes, signals are produced so that they can be differentiated
from each other and can be received error free. These techniques are widely ..."
Keysight Technologies at DesignCon 2018
Please save the date and join Keysight as the
proud host sponsor at
DesignCon 2018. Keysight's technical experts and application engineers will demonstrate
the most advanced design and test solutions, developed to solve today's most difficult
high-speed digital measurement challenges. What: Keysight at DesignCon 2018, Where: Santa
Clara, CA Convention Center, When: January 31st - February 1st, 2018 ...
Many Thanks to ConductRF for Continued Support!
ConductRF is continually innovating and developing
new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test
Cables for labs. ConductRF makes production and test coax cable assemblies as well
as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building
to choose from in the iBwave component library. They also provide custom coax solutions
for applications where some standard just won't do. Please visit
today to see how they can help your project!
Whenever I read the April issue of any magazine,
vintage or contemporary, lurking in my mind is whether it is an attempt at an April Fools
"gotcha." The article title is usually the first clue that the author is trying to punk
me at least provides a sporting chance. Take for instance this "Analog
Logic" piece in the April 1972 edition of Popular Electronics. It could
easily be a hoax, so I proceeded cautiously. It turns out to be completely legitimate.
James Hannas provides a few examples of how analog circuits can be used to perform mathematical
functions that are easily handled by logic circuits. Of course prior to the introduction
of readily available ...
MLinkPlanner Microwave Communications Link Planning Software
Mr. Oleg Sakharov, Director of the Center of Telecom.
Technologies, LLC, recently sent me information on the
MLinkPlanner software for performing microwave communications link design. Judging
only from the provided screenshots and the online documentation, MLinkPlanner looks to
be very user friendly and loaded with features. I downloaded the 7-day free trial and
did a quick fictitious link between my house in Erie, PA, and the WBEN AM radio station
in Buffalo, NY. My route is mostly over Lake Erie, so there was not much in the way of
obstructions, other than the curvature of the earth ...
3-D Printed Objects Connect to WiFi Minus
"Researchers from the University of Washington
have successfully created a new breed of
3-D printed objects. These plastic objects and sensors are capable
of collecting all sorts of data, as well as communicating directly with other devices
on WiFi. Thanks to models the team is making available to the public, users will be soon
be able to create 3-D objects of their own. Although these devices will be made from
commercially available plastics, they will have one particularly unique feature: they
will be able to wirelessly communicate with other smart devices ..."
SK Telecom’s Fronthaul Technology Adopted as
5G Standard in Korea
"Small and mid-sized equipment vendors will have
a more receptive environment in which to do business in Korea thanks to SK Telecom’s
fronthaul technology being adopted as a Korean national standard, according to the operator.
SK Telecom's newly developed 5G network technology was adopted by
the Telecommunications Technology Association (TTA) at its annual conference in Seoul.
As SK explains it, a 5G network requires a higher base station density with a higher
capacity for data processing than 4G LTE. Such requirements emphasize the significant
Filters for Microwaves
By the time you get into the realm of microwaves,
wavelengths are so short that using discrete components for reactive elements is impractical
or impossible. That is where the "magic" of
electromagnetic fields kicks in. Prior to the advent of computer simulators, the
design, construction, and adjustment of distributed element printed circuit boards and
waveguide were not for the feint of heart. Whereas "seat-of-the-pants" tactics often
resulted in a successful circuit, guesswork was (and still is) too expensive in terms
of time and materials to be employed in the spectrum at and above microwaves. This article
from a 1969 issue of Electronics World magazine is ...
Reeve Observatory: Papers Related to
Radio and Radio Astronomy
RF Cafe visitor Dick L., a Ham radio
operator, wrote to let me know about a website he finds useful for his interest in radio
astronomy. The Reeve Observatory,
located in Anchorage, Alaska, is apparently the personal project of registered electrical
Mr. Witham Reeve, who has authored books for the IEEE Telecommunications
Handbook Series. Write-ups and lots of photos (including nifty
antenna setups) and plots are posted on the topics of lightning,
geomagnetism, radiation, radio science, space weather, and more. You might like taking
a few minutes to look around ...
Anatech Electronics' December Newsletter
Anatech Electronics, a manufacturer of RF and microwave
filters, has published its December newsletter. In it, Sam Benzacar writes his annual
and Microwave: The Year in Review." He addresses the emerging technologies that are
actually making 5G a reality in spite of the seemingly insurmountable obstacles presented
by the realities of physics. We've been there before with other newfangled technologies;
i.e., Bluetooth. Sam has a very quotable line regarding the driverless vehicle craze,
"And for laughs, there's always driverless vehicles, a goal driven (it seems to me) by
2D Material Integrates Digital Logic and Memory into One Chip
"Researchers at Stanford University have demonstrated
that field-effect transistors made from a single layer of molybdenum disulfide (MoS2)
can successfully drive resistive random access memory. The results, which were reported
last week at the IEEE International Electron Devices Meeting, represent a key milestone
blending of memory with logic in a monolithic 3D integrated chip.
The chip the Stanford researchers developed is known as a 1-transistor-1-resistor memory
RF Cafe Engineering Crossword Puzzle w/Weekly Headlines December
At least 10 clues in this puzzle with an asterisk
(*) are pulled from this past week's (12/11 - 12/15) "Tech Industry
Headlines" column on the RF Cafe homepage (see the Headline Archives page for help).
For the sake of all the avid
cruciverbalists amongst us, each week I create a new technology-themed crossword
puzzle using only words related to engineering, science, mathematics, chemistry, physics,
astronomy, etc. Enjoy ...
Beads Block Noise
The April 1969 issue of Electronics World
included a large number of articles on the topic of filter design and use. Included were
titles such as "LC Filters," "Practical Operating Limits for Filters," "Filters for Microwave,"
" Crystal Filters," and others were contributed by experts in the field from industry
and academia. This article on the use of
ferrite beads for blocking RF signals is more of a sidebar note than an article,
but it's still worthy of inclusion. Ferrite beads and toroids are still widely employed
for stopping radio frequency interference (RFI) on everything from AC power cords to
Fairview Microwave Waveguide to Coax Adapters for 1.7 GHz to
Fairview Microwave, a supplier of on-demand microwave
and RF components, has launched a new series of
waveguide to coax adapters that cover a frequency range of 1.7 GHz
to 110 GHz in 22 waveguide bands. Typical applications include test benches, instrumentation,
high efficiency RF/Microwave transmission, MILCOM, SATCOM, radar and telecom. Fairview's
new line of waveguide to coax adapters consists of 77 models in sizes of WR-10 to WR-430.
These adapters are offered in a wide selection of waveguide flanges, sizes and materials.
They support 10 ...
Lenny & the Squigtones - "The Jolliest Fat Man"
Most people who were around in the 1970s remember
the sitcom "Laverne &
Shirley." It was popular as a part of the whole 1950s renaissance that was happening
with shows like "Happy Days," "Grease," "American Graffiti," et al, that captured the
attention of the parents of we teenagers as well as weselves[sic]. I was being held against
my will at Southern Senior High School at the time, and many of the kids adopted a "greaser"
lifestyle that included cigarette packs rolled up in t-shirt sleeves and Brylcreem in
the hair (mainly just the guys), leather jackets and
Keds high-top sneakers (guys and gals), and poodle skirts and saddle
Oxford shoes (mainly just the gals). Two weirdo characters, Lenny and Squiggy, made cameo ...
IEEE: Patent Power 2017
IEEE has published its "Patent Power 2017" review of the world's companies'
patent portfolios and the influence wielded thereby. The web page
includes an interactive table and chart that includes 18 industry scorecards with the
top 20 companies in each sector. The thumbnail shown here is with everyone involved,
but you can filter out non-relevant (per your definition)
industries. Circle size indicated relative patent power for a given country. The U.S.
still dominates overall. Apple is the figurative 800-lb. gorilla of electronics patents.
Honeywell "owns" aerospace and defense (which surprises me). Intel leads in semiconductors.
MIT rules in university patents. Take a look ...
SES Says FCC Should Make C-Band Registration
Easier, More Affordable
"C-band satellite service provider SES recently told the FCC that
if it wants a more accurate database of satellite earth stations, it should streamline
the registration framework to make it simpler and more affordable. As revealed in a Dec.
7 ex parte filing (PDF), SES met with FCC staff on Dec. 5 to discuss midband spectrum
and the history of C-band satellite. SES emphasized the benefit of C-band satellite capacity
not only to cable operators but to other media industry members as well, explaining that
virtually all of the video and audio programming ..."
Electromagnetic Water Cloak Eliminates
Drag and Wake
"Researchers have developed a
cloaking concept based on electromagnetic forces that could eliminate an object's
wake, greatly reducing its drag while simultaneously helping it avoid detection. The
idea originated at Duke University in 2011 when researchers outlined the general concept.
By matching the acceleration of the surrounding water to an object's movement, it would
theoretically be possible to greatly increase its propulsion efficiency while leaving
NI/AWR Example Highlights Impedance Matching of a 60-GHz Printed
Impedance matching of high-frequency components
is a key part of
antenna design that ensures maximum transfer of power between the
antenna and the transmitter / receiver circuitry. Antennas can be tuned to resonate at
the desired frequencies much more quickly and efficiently by first designing a matching
circuit rather than by making modifications to the antenna's physical dimensions. A new
application example describes a unique design flow using NI AWR Design Environment Microwave ...
Test Equipment Scene: VOM's, VTVM's and TVM's
For most needs to measure voltage, current, and
resistance, modern users of test equipment do not need to give much thought to the electrical
characteristics of the instrument being used. Other than setting the function switch
to the proper position (ohms, volts, amps, milliamps, etc.) and not exceeding the safe
measurement accuracy can usually be assumed to be good to within ±2 to ±5
of the least significant displayed digit. I.e., if the digital display shows 10.000,
then the actual value is likely in the range of 9.995 to 10.005. Autoranging even removes ...
Boeing to Install Digital Electronics in E-3
Sentry Cockpit Avionics
"Military avionics experts at the Boeing Co. are
moving forward with a project to upgrade the cockpits of U.S. Air Force
E-3 Sentry radar aircraft with modern commercially available, digital
electronics under terms of a $46.3M order announced Thursday. Officials of the Air Force
Life Cycle Management Center at Hanscom Air Force Base, are asking the Boeing Defense,
Space & Security segment in Oklahoma City to continue work on the E-3 Airborne Warning
and Control System (AWACS) Diminishing Manufacturing Sources ..."
Modelithics Co-Founder Dr. Tom Weller Named IEEE Fellow
is pleased to share the news and congratulate
Dr. Thomas Weller, the company's co-founder, on being named IEEE Fellow by the Institute
of Electrical and Electronics Engineers. This high designation is given by the IEEE Board
of Directors to persons having a history of significant accomplishments in the fields
of electrical engineering. Dr. Weller has been recognized for his extensive contributions
in the area of advanced RF and microwave modeling techniques for surface ...
On-Chip Metal-to-Metal Tunneling Makes
Light Without Lasers
"Light made on CMOS chips using
quantum tunneling could be used for optical interconnect and chemical
sensing, according to physicists at King's College London. Kings College gold nano-rod
tunneling The technique involves constructing a ~1 nm gap between two metal electrodes
(see diagram), and then using a potential difference to promote electron tunneling across
the gap. This tunneling occurs in two forms: elastic and inelastic, King's physicist
Dr Pan Wang told ..."
How to Tame Electromagnetic
Interference in Fabs and Beyond
"Electromagnetic interference (EMI) is an increasingly
important topic across the global
electronics manufacturing supply chain. Progressively smaller geometries
of ICs, lower supply voltages, and higher data rates all make devices and processes more
vulnerable to EMI. Electrical noise, EMI-induced signal generated by equipment, and factors
such as power line transients affect manufacturing processes, from wafer handling to
wire bonding to PCB assembly and test, causing millions of dollars in losses ..."
4 Facts About Magnets for Electric Vehicles
"There are four main types of
magnets: ceramic (ferrite), AlNiCo, Samarium Cobalt (SmCo), and Neodymium
(NdFeB). The latter is one of the most commonly used in motors for hybrids vehicles and
EVs. Neodymium magnets have higher remanence, along with much higher coercivity and energy
production, but often lower Curie temperature than other types. Special neodymium magnet
alloys that include terbium and dysprosium have been developed with higher Curie ..."
Mac's Service Shop: TVI from the Victim's Viewpoint
When I read this installment of Mac's Service
Shop, in Popular Electronics magazine, the first thing that came to mind was
my own experience with
television interference (TVI) when I was a kid. In that case, the transmitter of
my radio control system for a model airplane was the culprit. The frequencies and channels
are almost exactly the same as reported in this infodrama. In the 1970s, citizen band
(CB) radios operated in the 27 MHz realm, as did my R/C transmitter. During summer
vacation from junior high and high school, I would run my model airplanes up down the
street in front of my house, getting up just enough speed to lift off and then immediately ...
QuinStar Power Amplifiers Boost Radar, Communications, Defense
NASA's Jet Propulsion Laboratory issued the following
notice from their NASA Spinoff Database:
Power Amplifiers Boost Radar, Communications, Defense Systems. As a subcontractor
under an SBIR contract from the Jet Propulsion Laboratory,
Inc. of Torrance, California, developed a solid-state power amplifier of unprecedented
efficiency. While most comparable devices lose 20% of their amplified energy when their
signals recombine, QuinStar's lose 8%. The solid-state technology ...
Beam-Switching Successfully Tested on Predator
"Two satellite beams (or more) are better than
one when it comes to data transfer and anti-jamming measures between satellites and drones.
At least that's what last month's first successful test of beam-switching technology
on an MQ-9 Predator drone seemed to show. Over the course of the testing, the drone flew
1,075 nautical miles and was able to switch smoothly between two
spot beams multiple times throughout the trial. While traditional
wide-beam satellites use one beam to cover thousands of miles, the satellites ..."
High-Density PC Boards
You will probably chuckle at the sight of the printed
circuit board being an example used in an article about
high density PCB production. However, in 1969 it was heralded as leading edge technology.
Remember, though, that surface mount components the size of a grain of salt were unheard
of so such a board probably represents a bunch of leaded components being closely packed
together with the biggest concern for density being heating / cooling issues. Part of
the big deal with this board, when you read the article, is that it is one of eight that
were produced on the same substrate and then singulated ...
Cuprate Stripes May Link to Ultrathin
Semiconductor Use 'Rust' as Insulator
"Chip makers appreciate what most consumers never
knew: silicon's virtues include the fact that it 'rusts' in a way that insulates its tiny circuitry. Two new ultrathin
materials share that trait and outdo silicon in other ways that make them promising materials
for electronics of the future. Facebook Twitter Email By Andrew Myers The next generation
of feature-filled and energy-efficient electronics will require computer chips just a
few atoms thick. For all its positive attributes, trusty ...
It's Beginning to Look a Lot Like
[a White] Christmas
Call me nuts, but I have always loved a white
Christmas. That's why most of my life has been spent in northern climes. Judging by the
heap on the bird feeder, about 6-8" has fallen so far, and then there's another 6-8"
due by tomorrow evening. The pic is from a
Wansview 720p webcam(~$40, free access from
anywhere) looking out my front window. There's one in the basement, too, for monitoring
the homestead when gone. I installed a couple of these webcams at my daughter's house,
too - very simple to set up. Now we can see her North Carolina horse farm goings on anytime.
Notable Tech Quote: Werner von Siemens
have little worth. The value of an invention lies in its practical implementation." -
Werner von Siemens, 1865. The unit of electrical conductance is named
Terminal Radio Corp. Christmas and New Year Greeting
Other than today's QST magazine being
a larger format and being printed in full color, there is not much difference fundamentally
between the amount of Christmas-themed company advertisements now and half a century
ago. Those from the last century were more likely to incorporate a religious message
in addition to or instead of a secular message to their customers.
Terminal Radio Corporation was located in midtown Manhattan. Google Maps can find
West 45th Street and it can find Cortlandt Street, but they evidently no ...
Pentagon Spending More on Emerging Tech
"The Department of Defense spent $7.4B in fiscal
year 2017 on cloud computing, big data and artificial intelligence technologies, according
to a recent report by public-sector contracting analytics firm Govini. That represents
32% increase since 2012, with more specific technologies like quantum
computing, virtual reality and machine learning seeing some of the bigger boosts in investment.
While cloud, AI and big data all saw spending jump over the past five years, AI accounted
for the bulk of the increase in spending ..."
Army Developing Lasers That Pierce Fog, Dust
to Destroy Targets
"A lot of people think that
high-energy lasers, or HELs, can't penetrate fog, rain and dust,
said Thomas Webber, director of the Directed Energy Division's Technical Center, U.S.
Army Space and Missile Defense Command. That's just plain wrong. The key to making HELs
work in poor atmospheric conditions is something called "adaptive optics," he said, adding
that the Army is continuing to make more and more improvements on its adaptive optics
New Invention Could Lead to Novel Terahertz
"A new device could open new avenues for the generation
high-frequency radiation with applications in science, radar, communications,
security and medical imaging. Ever since the discovery of X-rays in 1895, their ability
to reveal things hidden to the human eye has created endless opportunities. But X-rays
by far aren't the only option to see the world with different eyes. Researchers hope
to make better use of a different form of light, called terahertz radiation ..."
Anatomy of a Lightning Bolt
Mankind has been fascinated with -and scared of
- lightning since the dawn of civilization. It's incredible power has been the cause
of much destruction and loss of life. Benjamin Franklin famously proved that lightning
is in fact a form of
electrostatic discharge. He exploited that knowledge to invent grounded lightning
rods for tall buildings, thereby nearly totally halting the lightning-caused fire epidemic
in Philadelphia and other cities. Much investigation and implementation of lightning
discharge mitigation schemes has occurred to safeguard against catastrophic events. Ultimately,
though, says author David Heiserman, 'Lightning has ..."
Identifying and Isolating Signals Using
Radio Frequency Photonics
QuinStar Technology designs and manufactures
mm-wave products for communication, scientific, and test applications along with providing
microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, Oscillators,
Switches, Attenuators, Circulators, Isolators, Filters, Waveguide, Antennas, Phase Shifters,
Transceivers, Mixers, Detectors. QuinStar specializes in cryogenic
amplifiers, circulators, and isolators. Please visit QuinStar today to see how they can
help your project ...
WiDeo: A Motion Tracing Camera Using WiFi
in operation: The compact WiFi AP in the study integrates WiDeo's motion tracing functionality,
and can reconstruct the hand movement made by humans in the living room. WiDeo traces
motion even though the AP is separated by a wall and does not have a LOS path to the
humans, and doesn't require that the humans have any RF devices on them. WiDeo has broad
applications such as security, navigation, search and rescue, and people monitoring ..."