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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.
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 firstname.lastname@example.org so we can work together to solve your most challenging interference problems.
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.
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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.
Anatech Electronics, Inc.
70 Outwater Lane
Garfield, NJ 07026
Posted October 26, 2016