|
Anatech Electronics, a manufacturer
of RF and microwave filters, has published its October 2016 newsletter. As always, it includes both company
news and some tidbits about relevant industry happenings. This month, Sam Benzacar discusses the topic
of "Carrier Aggregation: The Next Interference Challenge?," China's world's largest Aperture
Spherical Telescope, Israel's drone-fighting radar, the The Navy's new 'Stealth' destroyer, and
Microwave energy being used in fracking operations . Anatech's business is to make certain that system
and circuit designers have capable filters available to assure successful implementation.
Carrier Aggregation: The Next Interference Challenge?
 By Sam Benzacar
In our newsletters this past year I've been pointing out possible interference problems that may
crop up in both new applications like the Internet of Things (IoT) as well as public safety, and
cellular networks
They're all real concerns and can generally be dealt with using RF and microwave filters as well
as through prudent design. However, one I haven't yet touched on is carrier aggregation which has
its own interference issues.
Carrier aggregation allows multiple LTE carriers, typically not contiguous and each with a
bandwidth up to 20 MHz (currently), to be combined to produce wider signal bandwidths and thus
faster data rates and greater capacity. Carrier aggregation is incorporated within LTE-Advanced for
use in the downlink and provides for signal bandwidths up to 100 MHz. In the future this may
increase dramatically as was defined in Release 13 finalized in July, that proposes up to 32
aggregated carriers.
The interference issues arise for several reasons, one of which is the potential for harmonics of
the fundamental frequency of a transmitted signal in one band to fall within others bands,
decreasing receiver sensitivity. The most widely used remedy for this is the use of filters with
high rejection characteristics in the receiver front end. They are extremely effective and must
attenuate the interfering signals while also keeping insertion loss as low as possible. This becomes
an even greater challenge when the bands to be aggregated are close to each other, a situation that
may call for the use of multiplexers (also based on filters).
Only channels in the downlink path are currently being aggregated but uplink frequencies are
almost certain to added in the future, which presents another set of potential interference problems
primarily related to intermodulation distortion that can affect a wide variety of services beyond
those used by cellular networks. Once again careful design combined with RF and microwave filters
are the most potent resources for keeping it in check.
If you're involved in the design of current LTE-Advanced subsystems or systems, interference
challenges will sooner or later need to addressed, and Anatech Electronics can help you sort them
out. Over more than 25 years, we're resolved interference issues identical to those that loom ahead
as the use of carrier aggregation expands. So please call us at (973) 772-4242 or send an email to
sales@anatechelectronics.com so we can work together to solve your most challenging interference
problems.
What's News
China Turns on Huge Radio Telescope
 China's Aperture Spherical
Telescope in a natural basin in the country's remote southwest has just begun searching the heavens
for distant stars and galaxies. With a diameter of 500 meters it's the world's largest radio
telescope and cost $180 million to build, moving ahead of the 300-meter Arecibo Observatory in
Puerto Rico that long held the size record. The official Xinhua News Agency said hundreds of
astronomers and enthusiasts watched as the telescope went online for the first time, detecting
gravitational waves and electromagnetic emissions from stars and galaxies, and (who knows?) even
intelligent extraterrestrial life. The massive structure is made of 4,445 panels, and require
requires absolute quiet, so to speak, within 3-mile radius, which required relocation of more than
8,000 people from eight villages. It has twice the sensitivity of Arecibo and five to 10 times the
surveying speed, according to Xinhua. Tourists are welcome and can watch from an observation deck on
a nearby mountain.
Better Collision Avoidance or Drones
Israeli radar startup Arbe Robotics in Tel Aviv has developed a built a radar system designed for
use by drones that can allow the aircraft to detect and avoid objects up to 1 km away. This is far
more useful in some applications requiring non-line-of-sight capability than the cameras drones
typically use for this purpose, which can only "see" up to 50 meters. The system detects obstacles
in 2 milliseconds, making it appealing for use in delivery drones or government surveillance drones.
The Navy's new "Stealth" Destroyer
 The Navy's newest destroyer, the 610-ft.-long USS Zumwalt boasts what the Navy considers stealth
capability with an angular shape to minimize its radar signature, and is designed to be difficult to
detect by radar as well as electro-optic and visual means. It houses an advanced radar and many
other sensors as well as jamming capabilities and can send 600 rocket-powered projectiles to targets
up to than 70 miles away. It is expected to carry Tomahawk cruise missiles, Evolved Sea Sparrow
Missiles, standard surface-to-air missiles, and anti-submarine rockets from 80 missile tubes.
Huawei Shows Off Millimeter-Wave FTTH Solution
The fifth generation of cellular technology, 5G, is obviously associated with delivering
connectivity not just for smartphones but its first deployments may be in delivering broadband and
entertainment capability, wirelessly, to the home. Verizon said as much earlier this year and now
Huawei has announced a broadband solution that combines wireless connectivity at E-band with data
rates up to 10 Gb/s, while also employing existing fiber, copper, and coaxial cables to expand
coverage. Wireless delivery of these services presents a challenge to traditional
cable-and-fiber-based solutions as it is much less expensive and faster to deploy, eliminating the
need for laying fiber and its associated issues of rights-of-way acquisition, and reducing truck
rolls. Millimeter-wave transmission also has very low latency, which is critical for some
applications, which is why it is used by financial services companies in which every millisecond
counts.
Microwave Energy to Supplement Fracking
 With more than 1.5 trillion
untapped barrels of crude, the U.S. has huge untapped energy resources. However, as this oil is
trapped in oil shale it's sometimes not amenable to fracking, but not as it turns out to microwave
energy. By beaming RF energy at very high power levels to the shale formation to liquefy the crude,
it will then flow freely. The energy can raise temperatures to the required level over a span of 80
ft. It is also far less environmentally unfriendly than current methods than continue to raise
issues wherever fracking is used, and is less energy intensive. The technique is likely to begin use
next year.
Check out Our Filter Products
Cavity Band Pass Filters
LC
Band Pass Filters Cavity Bandstop/Notch Filter
About Anatech Electronics
Anatech Electronics, Inc. (AEI) specializes in the design and manufacture of standard and custom
RF and microwave filters and other passive components and subsystems employed in commercial, industrial,
and aerospace and applications. Products are available from an operating frequency range of 10 kHz to
30 GHz and include cavity, ceramic, crystal, LC, and surface acoustic wave (SAW), as well as power combiners/dividers,
duplexers and diplexers, directional couplers, terminations, attenuators, circulators, EMI filters,
and lightning arrestors. The company's custom products and capabilities are available at
www.anatechelectronics.com.
Contact:
Anatech Electronics, Inc.
70 Outwater Lane
Garfield, NJ 07026
(973) 772-4242
sales@anatechelectronics.com
Posted October 26, 2016
|
