Wireless Systems Design

On The Wireless Front

Springfield, Virginia
A new solution to the poor signal quality of wireless networks is as economical as it is flexible: the Nearson 7-dBi high-gain rubber-duck antenna. Now, blind spots and patchy signals can be replaced by high-quality reception without the cost or power consumption of high-powered radios.

The Nearson 7-dBi antenna brings the performance of an infrastructure antenna to a portable antenna that is small, lightweight, and very cost effective. It attaches directly to standard connectors found on industrial radios or 802.11b&g access points. Range of reception in many environments is effectively tripled. This improved range reduces the need for extra access points, amplifiers, or repeaters, thereby saving both the cost of installation and its associated aggravation. Link quality is improved, reducing packet loss and increasing effective throughput.

Nearson's 7-dBi antennas are 11 in. tall, thin, flexible, and articulating. They come with industry-standard SMA and TNC connectors as well as reverse-polarity versions for FCC Part 15 compliance. There are models available with flying leads (a Nearson innovation in 1999) for OEM adoption with U.FL-compatible and MMCX connectors. These flying-lead models eliminate costly patch cables. They also offer a variety of methods to attach to an OEM's enclosure. The 7-dBi antennas are available immediately for volume production.

For more information, visit the company web site at www.nearson.com.

San Jose, California
The new MIC2203 step-down (buck) regulator from Micrel, Inc. draws ultra-low supply current. This IC targets applications that require low-noise DC/DC conversion, such as 802.11 wireless cards, USB applications, cell phones, and Mini Disk and MP3 players.

The MIC2203 is a high-efficiency, 1-MHz pulse-width-modulated (PWM) synchronous buck converter. It is capable of >90% efficiency across a wide load range. A proprietary gate drive minimizes switching losses, allowing the new device to draw just 650 µA of current while switching at 1-MHz fixed operating frequency. The MIC2203 operates from 2.3-to-5.5-V input voltages with an output voltage adjustable down to 0.5 V at 300 mA.

The MIC2203 is currently sampling with volume quantities available in 12 weeks. It is offered in 3-x-3-mm, MLF-10 and MSOP-10 package options. The MIC2203 is priced at $1.80 and $1.65, in 1K quantities, respectively. Lead-free options also are available. To learn more, go to www.micrel.com.

Sunnyvale, California
Maxim Integrated Products recently introduced the MAX2039. This high-performance, fully integrated, SiGe passive mixer was designed specifically for 2.5G/3G wireless-infrastructure applications. It claims to deliver an unparalleled combination of linearity, noise performance, and component integration. This single IC provides 34.5 dBm of IIP3, 24.4 dBm of IP1dB, 7.3 dB of noise figure, and a conversion loss of only 7.1dB. In addition, the MAX2039 exhibits excellent second- and third-order spurious suppression.

The MAX2039 is ideal for 1700- to-2200-MHz W-CDMA/UMTS, DCS/PCS/EDGE, cdma2000, and TDMA base-station applications, in which high linearity and low noise figure are critical for enhanced receiver and transmitter performance. The device offers a wide 40-to-350-MHz IF frequency range with a 1400-to-2000-MHz low-side LO injection range. An LO frequency range of 1900-to-2400-MHz is supported by the MAX2041, which has been optimized for high-side LO injection.

As a complete SiGe up- and downconverter, the MAX2039 integrates a state-of-the-art, double-balanced mixer core with an LO amplifier, two baluns, an LO switch, and dozens of discrete components. This integration reduces the total board space used by the mixer by a factor of 2.5x. In addition, it reduces the discrete part count by 33%. The MAX2039's 2RF-2LO performance also can ease the filtering requirements of close-in harmonics, thus leading to simpler and more cost-effective filter designs.

Frequency hopping is supported with the integrated SPDT LO switch with switching speeds of <50 ns and 45 dB of LO1-to-LO2 isolation. The on-board, 0-dBm drive LO buffer provides ±3-dB drive-variance control. It yields stable gain, NF, and IIP3 performance over temperature, supply, and input power. The device has excellent gain-variation performance of ±0.5 dB over the −40° to +85°C industrial-temperature range. IIP3 spread is similarly impressive at ±0.75 dB over temperature.

The MAX2039 comes in a 5-x-5-mm, 20-pin thin QFN. Lead-free packaging also is available. Prices start at $6.15 (1000-up, FOB USA). To learn more about the MAX2039 SiGe passive mixer, visit the company's web site at www.maxim-ic.com.

Schaumburg, Illinois
To expand its global reach, HUBER+SUHNER ELECTRONICS Pvt. Ltd. in Gurgaon started providing localized sales support, technical consulting, and logistics services to Indian customers. The new subsidiary is a wholly owned company of the Swiss HUBER+SUHNER Group. The goal of HUBER+SUHNER ELECTRONICS Pvt. Ltd. is to provide all customers with an exceptionally high product and service quality. The group also wants to contribute to the continuing improvement of India's technological capabilities.

The HUBER+SUHNER Group comprises global suppliers of components and systems for electrical and optical connectivity solutions. They focus on three defined markets: communication, industrial, and transportation. Their engineering expertise in radio-frequency technology, fiber optics, electrical cable, and polymer technology enables them to offer a broad range of products that satisfy top-quality standards. Their concentration on complex applications allows the company to stand out by adding value with special product features, customer-specific innovations, engineering, and other services.

In the communications segment, the group supports mobile and telephone operators, equipment manufacturers, and system integrators. It supplies an extensive line of high-quality products ranging from feeder and coaxial cables, connectors and cable assemblies, fiber-optic cables and fiber-management systems to assemblies and accessories, antennas, and lightning-protection components. The world's major operators, OEMs, and CEMs use HUBER+SUHNER products for their communication networks and equipment. Established connectivity solution providers apply their innovative and customer-specific components for error-free connections.

To learn more about the new subsidiary or the company, go to www.hubersuhner.co.in.

Sunnyvale, California
QuickLogic Corp. has unveiled a Wireless Application Portal on its web site. This comprehensive resource discusses the challenges associated with wireless system design. It also provides users with solutions to these challenges, particularly related to 802.11a/b/g Wi-Fi. This portal is located at www.quicklogic.com/wireless.

Initially, the QuickLogic Wireless Portal is focusing on various Wi-Fi solutions that are on the market today. One of the topics addressed at length is the integration of Wi-Fi technology into embedded systems. Portable embedded systems typically employ processors that do not have an integrated PCI controller. In contrast, most Wi-Fi devices on the market today do employ such processors. The connectivity of Wi-Fi chip sets within these systems is therefore a critical engineering dilemma. QuickLogic's Wireless Portal illustrates how this challenge can be addressed while meeting the stringent bandwidth, power, board-space, and cost constraints present in most portable embedded systems.

The wireless segment is the newest addition to the existing suite of application portals on the QuickLogic web site. The other portals include digital consumer, communications, and IP Security. To get more information about QuickLogic or the Wireless Application Portal, visit www.quicklogic.com.

Lenexa, Kansas
Fueled by record sales, AeroComm, Inc. just announced its move into a larger and more versatile world headquarters. The 30,000-ft.2 office, research and development lab, and manufacturing facility is located in the southwestern suburbs of Kansas City. The new facility will allow AeroComm to triple in-house engineering and manufacturing capabilities.

AeroComm attributed last year's growth to several factors: its comprehensive lineup of radio-frequency (RF) products, the emerging need for wireless connectivity in industry, and a successful strategy to serve new markets beyond the company's traditional stronghold. The company anticipates further exponential sales growth this year due in part to new RF product developments. Examples of such products include waterproof enclosures, Ethernet interfaces, masterless protocol, ZigBee-standard modules, and higher-power European-band products. Accordingly, the new building will accommodate AeroComm's mounting need for a world-class manufacturing area. There, its industry-leading modules and devices can be assembled and tested.

To learn more about AeroComm, go to www.aerocomm.com.

Milpitas, California
Recently, Linear Technology Corp. announced the LT3483—a 40-V, 200-mA inverting DC/DC converter with an on-chip Schottky diode in a ThinSOT package. The LT3483 utilizes a current-limited, fixed off-time architecture. This architecture delivers high efficiency over a broad range of load current while BurstMode operation allows quiescent current of only 40 µA. The LT3483's input voltage range of 2.5 to 16 V makes it ideal for single cell Li-Ion or multi-cell NiMH/NiCd and alkaline applications as well as more general-purpose fixed-rail systems. Its output voltage capability makes it well suited for a wide array of negative biasing applications including CCD, LCD, and general-purpose negative voltage supplies.

The LT3483 can deliver up to 70 mA at −5 V from a 5-V input. Additional features include an integrated feedback resistor output short-circuit protection. The LT3483's small package, high level of integration, and use of tiny surface-mount components yield a solution footprint of less than 40mm2. The LT3483 is available in a ThinSOT package from stock. Pricing starts at $2.05 each for 1000-piece quantities.

For more information on the LT3483, visit www.linear.com.

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