Defense Articles

The problems wireless carriers encounter with regard to tower siting and network interference could largely be things of the past with the implementation of “smart antenna” technology developed at Virginia Tech’s Mobile and Portable Radio Research Group (MPRG).

MPRG founder Ted Rappaport, a professor of electrical engineering at the university, said smart antenna technology is being tested by more than 12 companies. “Smart antennas are sort of in their infancy,” said Rappaport, who also is chairman of Wireless Valley Communications Inc. (see box, p. 2).
Smart antennas are designed to reduce the number of antennas needed to build out coverage of an area, known as the “range enhancement” function, and to increase the capacity of networks by reducing interference within the networks, which is called the “interference mitigation” function, Rappaport said.

…Fewer Cell Sites, Less Interference

By enhancing their antennas range, carriers are less likely to be forced to ask for approval of cell sites in residential areas. They also could need fewer cell sites altogether. “It removes the burden of frequency planning and makes site location less critical,” Rappaport said.

A federal court ruling last month allowing a Virginia city to deny tower siting proposals by two wireless carriers appears to indicate that even with the Telecommunications Act of 1996 as the bottom line, wireless carriers can’t tell local areas where to construct towers (MPN, Sept. 14, p. 1). One of the affected carriers, PrimeCo Personal Communications LLP, is asking the 4th U.S. Circuit Court of Appeals to reconsider its ruling.
Decreasing the amount of interference over carriers’ networks will allow room for more wireless transmissions. “Interference is the largest capacity user in most urban cell systems,” Rappaport said.

He added, though, that interference mitigation is “more of a challenge” than range enhancement. Solving network interference involves engineering work along an entire system, while increasing range can be done at individual cell sites.

There are obstacles to widespread implementation of the technology, but not insurmountable ones. “It’s extremely expensive right now,” Rappaport said, explaining that the technology costs 10 to 20 times what traditional antennas cost. “As deployment becomes more widespread and carriers gain confidence, that price will come down,” he said.

A second obstacle also touches on carriers’ confidence, though it’s not a cost factor. Rappaport said that like other industries, the “engineering inertia” of the wireless industry protects established practices at the expense of different ones that could be better.

“It’s very hard to go to new technology gracefully,” he said. “Smart antennas are no exception. It will take a little while.” He added that widespread deployment of all or selected elements of smart antenna technology should occur in three to five years.

Contactless proximity read/write device supports ITSO specification 2.1.1, including Calypso, and reads all specified Customer Media Device (CMD) types. Optimized for transaction time efficiency, unit is equipped with 4 integrated SAM sockets for security and 2 external antennas that can be connected. Product autonomously processes all ITSO-defined customer media operations and presents all data in independent formats to POS terminal.

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New reader generation supports latest standards and comes with incorporated ITSO application for easy integration
Walluf, May 31, 2007 - Assa Abloy Identification Technologies (ITG), one of the leading providers of products and services in the RFID market, introduces a new ITSO compliant reader. The new reader generation supports the latest ITSO specification - including Calypso - and reads all specified Customer Media Device (CMD) types. The contactless proximity read/write device is especially designed for the requirements of the public transport industry and is optimized for best transaction times. Through an incorporated ITSO application it can easily be integrated into new and existing systems. A live demonstration of the reader’s functionalities will be given at Moving On conference in Cardiff, June 4th - 6th at the Assa Abloy ITG booth #15.
Typical usage scenarios for the new reader series are ticket vending machines, stationary ticket validators, on-board ticket validators, desktop ticket issuing or ticket production & personalization. The new reader is optimized to comply with the latest ITSO specification 2.1.1 as well as the new Calypso specification under ITSO. Especially designed for the requirements of public transport, the reader is equipped with two external antennas that can be connected and thus provides maximum flexibility during the integration process.

The reader autonomously processes all ITSO defined customer media operations and presents all data in independent formats to the point of sale terminal (POST). Four integrated SAM sockets ensure a high security level. All processing required by the ITSO Security Access Module (ISAM) to conduct customer media transactions is done automatically.

“Our new reader provides increased efficiency and optimized transaction times through the use of ITSO optimized commands in the communication protocol”, says Denis Scheller, Product Manager of Assa Abloy ITG. “This allows simultaneous execution of multiple operations by the reader.”

Through an incorporated ITSO application the reader can easily be integrated into new and existing systems. Via various interface options it connects to a PC or other host systems and a built in boot-loader enables firmware field upgrades via multiple interfaces.

Assa Abloy ITG will present this new reader at the Moving On Conference in Cardiff, which takes place from June 4th to 6th. For a live demonstration of the reader’s functionalities please visit the Assa Abloy ITG booth #15.

For more information about the Moving On Conference please visit http://www.moving-on-conference.co.uk/

About Assa Abloy Identification Technologies (ITG)

Assa Abloy Identification Technologies (ITG) is a leader within the ID management and Radio Frequency Identification (RFID) markets. The company develops, manufactures and markets RFID components, products, and services typically deployed within national ID and e-passport programs, corporate access control, supply chain management, animal tagging, financial transactions, transport and various industrial or manufacturing solutions. Assa Abloy ITG is a merger of ACG Identification Technologies, OMNIKEY, Sokymat and VisionCard and Novacard do Brasil.

Assa Abloy ITG has over 900 employees and 25 sales offices in all continents. The company’s headquarters are located in Walluf, Germany. ITG is part of the Global Technologies Division of the ASSA ABLOY Group.

The AS-3900A antenna, NSN 5985-01-308-8988, used with the SINCGARS ground radio is getting damaged far too often.

The damage is happening when it’s assembled, when it’s installed, and when it’s removed. The damage is happening to both the lower and upper antenna elements and the antenna spring base.

The antenna is not getting a break! Or at least not a good one.

Most of the damage is to the threads on the elements and the base and it’s happening because proper assembly, installation and removal procedures are not being followed.

DO:

* Line up the upper and lower elements and gently push the elements together until the assemblies fit snugly.
* Rotate the upper element clockwise onto the lower element until the two elements are firmly attached.

* Carefully rotate the upper element counter-clockwise to disconnect the upper element from the lower element and carefully separate the elements.

DON’T:

* Overtighten the elements! Over-tightening the elements will increase the likelihood of damage to interior components–like the contact point–of the upper and lower elements.

DO:

* Carefully line up the ferrule on the lower antenna element assembly with the threaded base on the antenna spring base.

* Slowly hand-tighten the ferrule by wrapping your hand around the metal ferrule and rotating the ferrule clockwise until the antenna is firmly attached to the spring base.

* Reverse the procedure to disconnect the lower antenna element from the spring base.

The Benchmark Survey System replaces legacy NGA conventional survey techniques with a GPS-only system, maintaining sub-millimeter positioning accuracy while increasing throughput by 400 percent, with an 85 percent decrease in manpower. Results agree with recent NGA precise survey data to better than 0.6 mm horizontal and better than 1.0 mm vertical.

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Since 1976, the National Geospatial-Intelligence Agency (NGA) has supported precise geodetic survey applications at the Holloman High Speed Test Track (HHSTT) at Holloman Air Force Base, New Mexico. Each survey element had individual stringent standard error criteria developed to meet or exceed the Air Force’s accuracy requirements; current NGA survey techniques at the HHSTT yield an accuracy of approximately 1 millimeter (2-sigma, each axis).
The HHSTT supports ground-level hypersonic testing of various propulsion systems, aerodynamic platforms, ejection seat systems, weapons systems, and targets. Its 9.6-mile length (15.5 kilometers) supports testing at speeds in excess of Mach 8; the HHSTT holds the current land speed world record at 9,465 feet/second (2,885 meters/second, or 6,453 miles per hour).

The HHSTT is a pair of continuously welded heavy duty crane rail sections, spaced approximately 2 meters apart and supported by a U-shaped concrete foundation. Track alignment fixtures are located every 52 inches (1.3 meters) along the entire length of each rail to secure it to the foundation. These fixtures permit incremental lateral and vertical adjustment of the rails. FIGURE 1 provides a cross-section view of the HHSTT.
The very high velocities obtained on the HHSTT mandate exacting control of the rails’ straightness and alignment. The Air Force routinely manipulates the rail, meter-by-meter via the track alignment fixtures, to maintain straightness and rail-to-rail spacing. All measurements made in support of these adjustment activities are referenced to 1,018 survey benchmarks installed along the entire length of the track. The Air Force requires survey positions for all the benchmarks that are accurate at the single-millimeter level, relative to a local reference frame.

Legacy Methods

The NGA has coupled precise geodetic survey instrumentation and standardized acquisition methods to meet customer challenges at locations throughout the world for several decades. In 1974, NGA (then the Defense Mapping Agency) conducted a study of HHSTT and the geodetic survey requirements imposed by the Air Force’s 6585th Test Group (now the 46th Test Group) at Holloman. This study determined that an eight-man crew, with a large inventory of geodetic survey equipment, would be needed on a continuing basis to meet the production schedules of the HHSTT, based on a shorter 35,000-foot (10.7 km) track length at the time.

FIGURE 2 depicts the evolution of this process from 1976 to the present. NGAs overall goal at the HHSTT has been to establish a database capable of serving as a tool to continuously monitor the HHSTT and its environment; the NGA geodetic survey results allow the 46th Test Group to keep the two HHSTT rails precisely aligned in support of ever-increasing test velocities.

Benchmark Survey System

Although the measurement quality achieved through NGA’s current survey process is satisfactory, the process is manpower-intensive and slow. This has motivated NGA to seek a more efficient method. In July 2004, under the sponsorship of NGA, Applied Research Laboratories, The University of Texas at Austin (ARL:UT) began the development of an alternative GPS-only survey system for the HHSTT, called the Benchmark Survey System (BSS). Two fundamental requirements were imposed on the BSS at the outset of the development: high accuracy and high throughput. The BSS has been designed to measure benchmark-to-benchmark vectors to an accuracy of 1.0 millimeter or better (1-sigma, horizontal and vertical components), and to support a full survey of the HHSTT in six weeks with a crew of four.

ARL:UT has developed and deployed the entire system; it includes commercial hardware components such as the GPS receiver and antenna, custom-designed mounting hardware specific to the HHSTT, and custom data processing software consisting of both a graphical interface and a GPS network position estimation application. In this article, we compare BSS results with a recent NGA survey, showing that the BSS has achieved the accuracy and throughput goals in the requirements.

Operating Principles. BSS hardware consists of 25 self-contained GPS data collection and storage units, or survey nodes, deployed together so that GPS observations are recorded concurrendy at 25 benchmarks along the HHSTT. Each survey node consists of a ruggedized electronics enclosure containing a GPS receiver, a single-board computer, a rechargeable battery pack and supporting electronics, plus a GPS antenna with a mechanical mount that supports the antenna and provides precise control of its location relative to the survey benchmark.

Dielectric resonator antenna handbook.

Petosa, Aldo.

Artech House

2007

308 pages

$119.00

Hardcover

Artech House antennas and propagation library

TK6590

The final two decades of the 20th century saw the emergence of the dielectric resonator antenna as a viable alternative to conventional low-gain elements such as dipoles, monopoles, and microstrip patches. Petosa (antenna design and development, Communications Research Centre, Canada) synthesizes the growing body of knowledge about them into a single volume that can serve as a textbook or a design handbook. The example designs use simple equations for graphs to allow rapid design without resort to complex analytical or numerical calculations.

A method of arraying of receiving radio antennas involves utilization of all of the signal information available across a broad spectral band that includes any signal(s) of interest. As used here, “arraying” signifies combining the signals received by multiple antennas at different locations in such a way as to improve reception, as though one had a single larger antenna. Going beyond synthesis of a larger antenna, the present method also provides for extraction of Doppler frequency shifts and differential delays of signals, thereby enabling the generation of information on the ranges and velocities of signal sources. The method was devised to enhance spacecraft-tracking and -telemetry operations in NASA’s Deep Space Network (DSN); the method could also be useful in such other applications as radio astronomy, commercial satellite communications, and radio (including television) broadcasting.
In this method, the signals from the multiple antennas in an array are combined in real time by use of correlation processing, among other techniques, implemented by a combination of analog and digital electronic hardware and software. The signal received at each antenna is characterized by a delay and a Doppler shift that depend on the relative position and motion of the antenna and the spacecraft or other signal source. In order to achieve full-spectrum arraying, it is necessary to alter the signal received by each antenna to make its delay and Doppler shift equal to the delays and Doppler shifts of the similarly altered signals received by the other antennas. The altered signals are then combined coherently to obtain an improved detection of telemetry and navigation data.
In the original DSN application (see figure), the signals received by as many as eight geographically diverse antennas are processed by full-spectrum receivers (FSRs) followed by a full-spectrum combiner (FSC). The analog signal from each antenna is first down-converted to an intermediate-frequency (IF) band centered at 300 MHz. Then in an FSR, the IF signal is subjected to a combination of analog-to-digital (A/D) conversion and frequency down-conversion that yields an in-phase (I) and a quadrature-phase (Q) data stream, each consisting of 8-bit samples at a rate of 16 megasamples per second. The delay and phase of the I and Q streams from each antenna are altered by use of a delay line and a phase rotator. Adjustment is made first by using delay prediction, followed by a feedback measurement of residual delay and phase by the FSC.

In the FSC, cross-correlations of upper and lower sidebands from different antennas (e.g., of the upper sideband received by antenna 1 with the upper sideband received by antenna 2) are computed. The correlations contain information on frequency-dependent and frequency-independent phase offsets related in known ways to differential delays and Doppler shifts. The correlations are processed to generate phase and a delay offset for feedback to each FSR. The I and Q data streams from the FSRs are weighted and summed; the sum signal is then subjected to digital-to-analog (D/A) conversion and frequency up-conversion to obtain the desired enhanced IF signal.

The Titan Corp. and its subsidiary, e-tenna Corp. launched its new AccuWave product line. AccuWave is designed to improve the performance and reduce the size and cost of global positioning system antennas for high-precision applications.

AccuWave-enhanced GPS antennas use AMC technology to filter out and greatly reduce bounced signals. AMC attenuates multipath, thus creating a near-perfect antenna groundplane and significantly improves the accuracy of GPS systems, which is critically important for high precision applications like surveying.
In addition, AMC technology is realized using thin and low-cost printed circuit boards, rather than today’s standard method of placing the antennas on a machined aluminum groundplane. This results in antenna that are lighter, smaller, and more flexible than today’s antennas, thus enabling engineers to incorporate GPS functionality into a wider range of products.

A document proposes self-deploying spacecraft radar antennas based on cold hibernated elastic memory (CHEM) structures. Described in a number of prior NASA Tech Briefs articles, the CHEM concept is one of utilizing open-cell shape-memory-polymer (SMP) foams to make lightweight structures that can be compressed for storage and can later be expanded, then rigidified for use. A CHEM-based antenna according to the proposal would comprise three layers of microstrip patches and transmission lines interspersed with two flat layers of SMP foam, which would serve as both dielectric spacers and as means of deployment. The SMP foam layers would be fabricated at full size at a temperature below the SMP glass-transition temperature (T^sub g^). The layers would be assembled into a unitary structure, which, at temperature above T^sub g^, would be compacted to much smaller thickness, then rolled up for storage. Next, the structure would be cooled to below T^sub g^ and kept there during launch. Upon reaching the assigned position in outer space, the structure would be heated above T^sub g^ to make it rebound to its original size and shape. The structure as thus deployed would then be rigidified by natural cooling to below T^sub g^.

This work was done by Witold Sokolowski, John Huang, and Reza Ghaffarian of Caltech for NASA’s Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Electronics/Computers category.

Compatible with antenna Models AT2526 and AT5026, non-conductive Model AP5010 is built on casters to facilitate movement in shielded room or in open site testing. Design allows test engineer to position antenna for vertical or horizontal polarization and permits antenna to be tilted at 30[degrees]. Antenna Model AT2526 covers frequency range from 26-250 MHz and accepts up to 15 kW input power, while Model AT5026 covers 26 MHz to 5 GHz and accepts up to 5,000 W.

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Souderton, PA - 10/25/04 - The RF/Microwave Instrumentation division of AR Worldwide has introduced a heavy-duty, non-conductive support and positioner for two of its high gain, log

periodic antennas. The new AP5010 positioner is compatible with antenna models AT2526 and AT5026.

The AT2526 antenna covers the frequency range from 26 - 250 MHz and accepts up to 15 kW input power. The AT5026 frequency coverage is 26 MHz - 5 GHz; it accepts up to 5000 watt

input power.

The new antenna positioner is built on casters for easy movement in a shielded room or in open site testing. The design of the AP5010 also allows the test engineer to position the antenna for either vertical or horizontal polarization as well as permitting the antenna to be tilted at 30 degrees.

Like all AR Worldwide products, the new positioner is backed by AR Worldwide’s commitment to delivering not only exceptional quality, but outstanding value. At all AR Worldwide companies,

value is multi-dimensional. It includes innovative technology, advanced design, durability & longevity, mismatch capability, an unlimited support network, and less cost watt-for-watt than any other amplifier on the market.

The company supports its value proposition with an unsurpassed global support network and an exclusive “second-to-none, best-in-the-business” warranty.

For more information, contact AR Worldwide RF/Microwave, 160 School House Rd. Souderton, PA 18964 at 215-723-8181 or at www.ar-worldwide.com. For an applications engineer, call

800-933-8181.

One-chip, Model MT1120 integrates FM amplifier, AM amplifier, and automatic gain control functions for FM and AM bands. It amplifies signals with frequencies in 0.15-6.2 MHz range for AM and 76-162.4 MHz range for FM. Thresholds of AM and FM AGC function are variable and can be set according to application requirements. Temperature-compensated reference generator and high-output voltage op-amp combine to form automotive-qualified power supply.

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New highly integrated AM/FM amplifier chip, targeted for in-glass or small roof antennas, improves car audio reception and performance

Ingolstadt, Germany, November 8, 2004 - Bringing its radio frequency (RF) silicon expertise to the automotive electronics industry, Microtune, Inc. (NASDAQ: TUNE) today introduced an advanced one-chip AM/FM amplifier, the MT1120, specifically designed for integration into vehicle window-mounted antennas, small roof antennas or other integrated antenna systems. Compared to conventional discrete amplifiers, the new MT1120, through increased integration, offers amplifier-systems providers more functionality and higher performance in a miniature form factor.

Microtune is an RF silicon and systems company that develops tuners, amplifiers and transceivers targeted to the consumer and automotive electronics markets. The company is recognized for its breakthrough RF silicon technology, driving traditional RF module functions into high-performance single chips.

Unlike other amplifier chips on the market, the MT1120 integrates, into one device, the FM amplifier, AM amplifier, and automatic gain control (AGC) functions for the FM and AM bands. It amplifies the radio signal, compensating for the reduced performance of in-glass or small roof-mount antennas. The MT1120 offers extreme large signal handling capability and low-noise performance. These features, combined with its integrated AGC functionality, yield improved sensitivity and performance under difficult reception conditions, such as those resulting from weak signals or overload. The MT1120’s high degree of integration, very small size and superior performance also contribute to its overall system efficiency and lower RF solution cost.

“Automotive suppliers are rapidly expanding the use of integrated antenna systems in automobiles across an increasing number of makes and models,” said Barry Koch, Vice President and General Manager, Microtune’s Automotive Business Unit. “The industry has been looking for an integrated amplifier solution that meets increasingly strict performance and extreme automotive temperature-range requirements, while, at the same time, offering a reduction in overall systems cost. Our experience in developing high-performance RF silicon -plus our track record in developing industry-leading AM/FM, car-TV and telematics tuners- paved the way for the MT1120’s advance in automotive component technology.”

Application Flexibility

The MT1120 is designed for single-antenna systems, but is also well suited for implementation in antenna diversity systems, where multiple amplifiers are required to support multiple antennas. In addition, the application flexibility of the MT1120 permits system providers to optimally match varying antenna structures with different radio configurations. The MT1120 is also designed to conform to the applicable specifications of major worldwide carmakers, enabling it to support automotive radio systems across global markets.

Engineered for High Functional Integration and Superior Performance

The MT1120 is an advanced, low-power, single-chip amplifier that integrates two true-RMS power detectors and two uncommitted op-amps, realizing an AGC function for AM and FM by simply adding external PIN diodes. The thresholds of the AM and FM AGC function are variable and can be set according to the application requirements for system optimization. The on-chip temperature-compensated reference generator and high-output voltage op-amp combine to form a low-cost, reliable, automotive-qualified power supply, which can be connected directly to a non-regulated automotive electrical system.

The MT1120 is capable of amplifying signals with frequencies in the 0.15 MHz to 6.2 MHz range for AM and 76 MHz to 162.4 MHz range for FM. External components determine the gain of the AM and FM amplifiers and can also be modified to extend the operating frequency of the MT1120.

The AM amplifier uses highly sophisticated design technology to reach low noise, very low distortion, high-input impedance and its capability to drive very low-output impedance. The FM amplifier is matched to 50 ohms and is designed for low noise and very low signal distortion. These characteristics are required for achieving high-end AM/FM system performance, particularly under critical reception conditions.

Pricing and Availability

The MT1120 amplifier is sampling now and is priced at $2.20 in quantities of 10,000. Initial production is planned for early 2005. To simplify evaluation and design, Microtune also offers an MT1120 Evaluation Board.