Communications
 271 results found for Communications, displaying items 1 - 20

August 2010
Mach-Zehnder Modulators Serve Radio Over Fiber
Millimeter-wave wireless communications networks can take advantage of frequency multiplication schemes that generate high-frequency signals from lower-frequency sources. In one case, frequency multiplication for radio-over-fiber links can be achieved by means of Mach- Zehnder-modulator (MZM) based schemes. With three MZMs biased at their minimum transmission points, and a tunable optical delay line placed between two of the modulators and...  — Muhammad Taher Abuelma’atti

August 2010
What is radio over fiber?
Radio over fiber technology is a growing part of many cellular communications network plans. As broadband services, such as high-speed data and streaming video, become more prevalent in cellular networks, the available bandwidth of those networks will be quickly consumed. In order to conserve or increase capacity, many network planners are looking to millimeter-wave links or optical cables between a base station (BS) and a central control station (CS) in order to route...  — Muhammad Taher Abuelma’atti

August 2010
Fast-Locking Techniques Benefit PLLs
A PHASE-LOCKED LOOP (PLL) -BASED frequency synthesizer requires a certain amount of time for the loop to settle and acquire phase/frequency lock. This settling time, which is determined by the loop characteristics, is inversely proportional to the loop bandwidth. Generally, a PLL’s locking time is shortened by widening that loop bandwidth. At Taipei’s National Taiwan University, a novel fast-locking technique for PLLs has been developed by Wei-Hao Chiu, Yu-Hsiang Huang, and...  — Nancy Friedrich

August 13, 2010
Inmarsat Taps Boeing For Additions To Its Ka-Band Satellite Network
Through the addition of three new 702HP Ka-band satellites to be built by Boeing, Inmarsat’s forthcoming Inmarsat-5 constellation will be positioned to provide a global high-speed mobile broadband service offering.  — The Editors of Microwaves & RF

August 12, 2010
Through-The-Earth Wireless System Provides Emergency Communications For Trapped Miners
Lockheed Martin conducted a successful in-mine test of its MagneLink Magnetic Communication System (MCS).  — The Editors of Microwaves & RF

August 12, 2010
Alliance Works To Launch The World's First Panorama Movie Distribution Platform On Smartphones
Kokusai Kogyo Co. (KKC) Ltd. and Ubitus Inc. have entered a strategic business alliance to develop online distribution technology of panorama movie contents. When finished, the collaboration between the two companies will result in the world's first panorama movie distribution platform in the mobile market.  — The Editors of Microwaves & RF

August 12, 2010
Nationwide 4G-LTE Wireless Broadband Network Integrates Satellite Coverage
LightSquared has introduced a nationwide 4G-LTE wireless broadband network integrated with satellite coverage.  — The Editors of Microwaves & RF

July 2010
Raise Awareness Of Satellite Interference
 — Robert Ames

July 2010
Satellite Markets Enjoy An Uptick
The term “satellite” conjures many images ranging from television service to cutting-edge military applications like the “mystery” satellites that provide surveillance over troubled areas. With so many automobile drivers equipped with Global Positioning Satellite (GPS) systems, however, satellite applications have become rather commonplace. Yet that does not mean they have lost their innovative edge. Emerging needs continue to open new markets and ...  — Nancy Friedrich

July 2010
Front End Fits SDR Picocells
Software-defined-radio (SDR) approaches are being used in compact cellular base stations, including in picocellular systems serving small areas such as onboard commercial aircraft. Wireless communications systems onboard an airplane must provide high-quality audio, video, and data services conveniently but without interference with the aircraft’s navigation systems. As a result, a picocell solution must perform with sufficient suppression of...  — Wei Hong , et al.

July 2010
ULP DECT Raises Acceptance Of Wireless Sensor Networks
THE NETHERLANDS—A technology that has been commercially available for more than 15 years is now gaining momentum in the growing home-automation, control, and security network industry. With the recent development of the Digital Enhanced Cordless Telephone (DECT) ultra-low-power (ULP) operating mode, the technology is nourishing the market for battery-powered wireless sensor/actuator networks. The development of DECT ULP was spearheaded by RTX Telecom ...  — Dawn Hightower

July 2010
Home Energy Is Managed With Mobile Phone
CAMBRIDGE, UK—A recent demonstration from ip.access and AlertMe.com showed how femtocells can be integrated into smart-home energy-management solutions. With femtocell integration, the AlertMe Energy service can automatically detect when the house is empty and power down lights, televisions, and other home appliances. The service also can switch the services back on when the resident returns home. For the demo, ip.access combined the AlertMe Energy...  — Dawn Hightower

June/July 2010 Defense Electronics Supplement
Simulator Serves 85-MHz Channels
Communications links often involve mobile transmitters or receivers, as in the case of satellite communications (satcom) systems and unmanned aerial vehicles (UAVs). Testing such communications links under realistic conditions involves a signal simulator rather than a conventional signal generator. One such signal simulator, the Telemetrix 400 Channel Simulator (T400CS) from RT Logic, was recently enhanced...  — Jack Browne

June 2010
Software Enables Operators To Create “AER-Aware” Networks
PARIS, FRANCE AND ULM, GERMANY—Mentum and Ubidyne have entered into a partnership to further extend the capability of Mentum Planet tools to support advanced Antenna Embedded Radio (AER) technology. Ubidyne’s Antenna Embedded Radios integrate all of the radio-frequency elements of a network directly into the antenna housing and improve quality of service while reducing network CAPEX and OPEX costs. With Mentum Planet’s ability to manage advanced antenna systems...  — Dawn Hightower

June 2010
UHF Solutions
IN ADDITION TO ITS0.25-µm QUBiC4Xi SiGe:C devices, NXP Semiconductors has developed an ultra-high-frequency (UHF) radio-frequencyidentification (RFID) solution for the fashion, retail, and electronics markets. The UCODE G2iL and G2iL+ achieve good read ranges based on a simple, single antenna solution (Fig. 1). In addition, the new chips feature a tag tamper alarm, several privacy-mode...  — Paul Whytock

June 2010
Indoor Wireless Networks Use White LEDs
WHITE LIGHT-EMITTING DIODES (LEDs) are considered the “green” alternative to conventional lighting methods. After all, they offer lower power consumption, lower voltage, longer lifetime, smaller size, and cooler operation than other lighting options. LEDs also can be used as a wireless communications transmitter. This capability stems from the fast response time and modulation of visible light for wireless communications. An optical wireless communications ...  — Nancy Friedrich

June 2010
Backplane Transceiver Draws 87 mW From 1.2-V Supply
TO ACHIEVE HIGHER DATA RATES in backplane communications, designers tend to improve input/ output (I/O) circuits instead of modifying the board. This approach is easier because of cost and compatibility issues. Yet the I/O usually requires higher power, which may dominate overall power consumption if conventional architectures and circuit structures are used. With novel design approaches, however, it is possible to relax the required power dissipation. For example,...  — Nancy Friedrich

April 2010
Digital Techniques Hold Key To 4G Infrastructure
Right now, many families rely on wirelesslocal- area-networking (WLAN) access points to provide Internet capabilities for multiple computers inside their homes. In the near future, however, such devices will be replaced by cellular femtocells. These smaller base stations are expected to be widely used in homes and small businesses to provide access to fourth-generation (4G) communications services. To enable these higherdata- rate capabilities,...  — Nancy Friedrich

April 2010
Forecast Rain Effects On Microwave Links, Part 2
Scatterers such as rainfall can impose hard-to-predict effects on the propagation of electromagnetic (EM) waves, often making analysis of the near-field and far-field antenna patterns and performance difficult. In order to provide a more meaningful approach to understanding the effects of scatterers on EM propagation, last month Part 1 of this study explored the influence of distributed scatterers on nearfield antenna EM propagation. Part 2 will now...  — Dr. John Howard

April 2010
Achieve LXI Certification In Just Five Steps
By standardizing and extending local-area networks (LANs), the LXI standard vows to put the power of the Ethernet and the Web inside test systems. For test systems, the resulting possibilities include local, remote, distributed, and time-aware design. To provide best practices for integrating LXI instruments into a system, the LXI Consortium has released a three-page white paper titled, “How to Get a Product LXI Certified in Five Steps.” To manufacture...  — Nancy Friedrich





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