ISSUE DATE: APRIL 2007  OPTIONS
Wireless

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April 2007 - In This Issue

[Cover Story]
Broadband YIGs Yield Fundamental Tones To 20 GHz
Microwave frequency generation relies on many exotic structures, including Gunn diodes, dielectric resonators, and carefully cut pieces of quartz crystal. But perhaps no oscillator approach is quite as detailed as sources based on yttrriumiron-garnet (YIG) spheres placed within a cavity and subjected to an electromagnetic (EM) field. Fortunately, the engineers at Micro Lambda Wireless (Fremont, CA) have devoted many engineering years to taming this technology, and leading to the...  — Jack Browne

[News]
Cables and Connectors Forge Critical Links
Coaxial cables and connectors support and multitude of functions in modules, subsystems, systems, and test etups. In the simplest terms, they provide a transmission path for high-frequency analog and high-speed digital signals. How well they do this depends on a number of factors, including materials, design, and workmanship. As this short survey will show, choices for microwave cables, cable assemblies, and connectors are many and selecting a supplier is often a matter...  — Jack Browne

[News]
Base-Station And Handset Advances Keep 3G Rolling Out
After the downturn in the early part of this decade, it took many cellular carriers longer than expected to upgrade their mostly second-generation (2G) networks. The carriers simply lacked the funds to enhance their infrastructure. Since then, however, the market has stabilized. In fact, consumers are purchasing cell phones and services at an ever-increasing pace. Cellular carriers are now hastening to finish their third-generation (3G) network rollouts. To help them ...  — Nancy Friedrich

[Design Features]
Spiral SIRs Form Dual-Band Filter
Bandpass filters are essential components in wireless systems design. While the filtering function is critical in removing interference, spurious, and other unwanted signals, the physical size required by many filter designs is often a limiting factor for many systems architectures. Fortunately, the authors have developed a complact microstrip bandpass filter (BPF) that is broadband enough to handle the two bands of wireless-local-area-network (WLAN) systems in the ...  — Chung-I G. Hsu , et al.

[Design Features]
Developing Designs For RFID Transponder Using DTMOS
Transponder design for radio-frequency-identification (RFID) circuits must overcome many of the challenges faced by other low-power electronic applications. RFID transponder circuitry must be low in cost, and must operate over long periods of time on limited power sources. Earlier in the article series (Microwaves & RF, September 2006, p. 57 and October 2006, p. 82), basic design strategies were presented for designing RFID transponder integrated circuits (ICs) and...  — A. Kordesch , et al.

[Design Features]
Monitor And Control Base-Station Power Amps
Cellular-communications evolution has involved increasingly advanced modulation schemes. In the latest-generation (2.5G and 3G) base stations, design strategies include methods for achieving high linearity while also minimizing power consumption. By monitoring and controlling the performance of the base station's power amplifier (PA), for example, it is possible to maximize the PA's output power while achieving optimum linearity and efficiency. Fortunately, the...  — Liam Riordan

[Design Features]
Controlling LO Leakage In Passive FET Modulators
Passive FET modulators are commonly used in wireless base-transceiver-station (BTS) equipment. These zero-intermediate-frequency (zero-IF) modulators can provide excellent linearity with low carrier leakage, although the effects of reactive terminations can influence the carrier-leakage performance. Unwanted leakage can result from the loss of local-oscillator (LO) rejection nulling because of the terminating impedances. Fortunately, some simple diplexer circuits can provide...  — Kathiravan Krishnamurthi

[Product Technology]
LDMOS RF IC Amplifiers Boost 100 W At 900 MHz
High output-power levels are generally considered the demesne of discrete transistors, and certainly beyond the reach of integrated circuits (ICs). But the latest LDMOSbased radio-frequency IC (RF IC) amplifiers from Freescale Semiconductor (www.freescale.com) will force designers to change their thinking on ICs and power, since these plastic-packaged amplifiers can generate 100 W output power from 869 to 960 MHz...  — Jack Browne

[Product Technology]
Couplers Channel High Power To 6 GHz
High-power capability in a passive component requires an understanding of the thermal conductivity of high-frequency circuit materials as well as insight into board layouts that will minimize heat buildup. These guidelines have served the engineers at Innovative Power Products (Holbrook, NY) well in the development high-power couplers, combiners, and terminations for applications from high frequency (HF) through 6 GHz. The company's focus is on passive...  — Jack Browne

[Product Technology]
Test Solutions Take Aim At High-Speed Physical Layer
High-speed serial-communications networks are delivering data and video at unprecedented (microwave) speeds. As the transmission rates increase, characterization of the networks and their component parts becomes more difficult, requiring special measurement tools. One of these is a set of new options for the Agilent J-BERT N4903A serial bit-error-rate tester (BERT) that add calibrated jitter injection capabilities for checking the effects of jitter on component and...  — Jack Browne

[Product Technology]
Two-Chip IF Receiver Prepares For 3G Standards
As mobile handsets evolve to offer more multimedia content, the wireless infrastructure must be equipped to support higher-data-bandwidth devices. A two-chip intermediate-frequency (IF) receiver solution from Analog Devices (Norwood, MA) provides the performance needed for next-generation, multi-carrier wireless base stations to meet emerging third-generation (3G) cellular transmission standards. The solution comprises the dual-channel AD8376 variable gain amplifier (VGA)...  — Nancy Friedrich

[Editorial]
Services Prey On Location
The argument for third- and fourth-generation (3G and 4G) cellular services is simple. Consumers are increasingly relying on their handheld devices to send text and photos, surf the Internet, and even take and share video clips. It follows that consumers would be interested in watching television programs, music videos, and more on their handheld devices. When the next generation of services combines with location-based services, however, there is the potential for...  — Nancy Friedrich

[Feedback]
Article Corrections
I was pleased to see that my article (written along with Nils Nazoa), "Evaluate Accuracy Of Portable VNAs," was published in the January 2007 issue of Microwaves & RF (p. 58) as planned. However, there are three points that I would like to bring to your attention regarding the article as published: The sidebar section, describing calculating return loss uncertainty and uncertainty in phase, is missing from the article. This is most...  — Nick Ridler

[Feedback]
Mentoring Is Still Needed
I urge every RF/microwave engineer to read your January Editorial ("Keeping That New Year's Resolution," p. 17) and take your advice. In the "good old days" most companies maintained extensive educational programs, but these days managers are reluctant to let engineers be away from work. Mentoring is also disappearing because senior engineers can barely keep up with their own workloads. Engineers must constantly upgrade their skills—even if it means that ...  — Les Besser

[The Front End]
Mobile Handset Upgrades To Double First-Time Sales In 2007
EL SEGUNDO, CA—Upgrade purchases of wireless handsets will more than double the level of first-time buys in 2007, an unprecedented event in the market, according to a report from iSuppli Corp's Tina Teng. After rising by 38.1 percent in 2005, first-time mobile-phone sales will drop by 33.2 percent in 2007, iSuppli predicts. Meanwhile, upgrade sales—i.e., purchases of phones by consumers who already own a handset—will rise by 56.7...  — Compiled by John Curley

[The Front End]
Nokia Is Leading Smartphone Market With 56 Percent
LONDON, ENGLAND—According to the latest research on smartphone markets from ABI Research, Nokia has maintained its leadership position with a 56.4-percent share of the 70.9 million units shipped in 2006. Nokia sold 40 million smartphones in 2006, compared to 28.5 million in 2005. Motorola also had a strong 2006 and occupied the second position with 8.5-percent market share, driven by the success of its Linux-based devices in China, most notably the...  — Compiled by John Curley

[The Front End]
Earnings By QUALCOMM’s BREW Publishers Exceed $1B Mark
SAN DIEGO, CA—QUALCOMM, Inc. announced that the worldwide community of BREW publishers and developers has now earned more than $1 billion from the sale of BREW applications and services since the first commercial deployment of BREW services in November 2001. "During the past five years, we are proud to have grown the BREW solution into a global premier wireless data service, and the $1 billion earned by BREW publishers and developers is a testament to the...  — Compiled by John Curley

[The Front End]
Kudos
HARRISBURG, PA—Tyco Electronics was named a recipient of Intel Corp.'s Preferred Quality Supplier (PQS) award for outstanding performance in providing products and services deemed essential to Intel's success. The company was recognized for its efforts supplying Intel with interconnects, microprocessor sockets, and passive components. Tyco Electronics and 43 additional PQS award winners were be honored at a celebration in Burlingame, CA on March 27. WARREN,...  — Compiled by John Curley

[Financial News]
Content Is Driving Wireless Data Revenue
Faced with a falling Average Revenue Per User (ARPU) for their voice services, mobile-communications providers are offering premium multimedia content in order to compensate for their reduced voice revenue per subscriber, according to the market-research firm iSuppli Corp. Voice ARPU fell by an average of five percent for the 13 key global wireless carriers profiled by iSuppli's Mobile Multimedia service. These carriers collectively represent more than 1 billion...  — Compiled by John Curley

[Company News]
Company News
CONTRACTS Elcoteq SE—Announced that it has been awarded a multiyear contract by Redline Communications. The agreement with Elcoteq will enable Redline to accelerate production to meet the demand for its RedMAX™ family of WiMAX products and RedCONNEX™ broadband wireless-infrastructure solutions. Elcoteq will be the primary EMS provider of manufacturing and new-product-introduction (NPI) services...  — Compiled by John Curley

[People]
People
Laurenson Is Appointed As picoChip's VP Of Engineering picoChip has named STEVE LAURENSON as its vice president of engineering. Laurenson joins picoChip from Agere Systems, where he served as Agere's Mobile Terminal Division's Technical Services director. He established Agere's European GSM Development Centre. See Associated Figure Telegenix, Inc.—JOE MILLER to the position of...  — Compiled by John Curley

[Educational Meetings]
Educational Meetings
SHORT COURSES Flomerics and AWR European Seminar Series May 3 (Stuttgart, Germany) May 9 (Gothenburg, Sweden) May 10 (Helsinki, Finland) May 15 (Milan, Italy) e-mail: info@flomerics.co.uk Internet: www.flomerics.com/microstripes/events 2007 IEEE Microwave Theory and Technique (MTT) Short Course May 5 (Menlo...  — Compiled by John Curley

[R&D Roundup]
Monopole Antenna Satisfies 5.8-GHz RFID Applications
Radio-frequency-identification (RFID) systems comprise a read/write device, such as a tag, and a transponder. Because it is attached to the object to be identified, the tag must maintain a very low profile while satisfying demands for low cost and small size. These requirements make it critical for the tag's antenna to offer wide impedance bandwidth, omnidirectionality, and high gain. It also must have a planar and compact structure. At Taiwan's National ...  — Nancy Friedrich

[R&D Roundup]
Phased-Array-Antenna Transceiver System Spans 10 To 35 GHz
Both commercial and military wireless-communication applications require systems that can operate over multi-frequency bands. Although a wideband phased-array antenna transceiver system has been looked at as a potential solution, its bandwidth is limited by several system components. At Texas A&M University, however, Seungpyo Hong, Sang-Gyu Kim, Matthew R. Coutant, Christopher T. Rodenbeck, and Kai Chang developed a compact, phased-array-antenna transceiver system...  — Nancy Friedrich

[R&D Roundup]
Wide Passband Filter Offers Good In- And Out-Of-Band Characteristics
Wideband-, multiband-, and wireless-communications systems demand compact, low-insertion-loss microwave bandpass filters. But wideband couple-line bandpass filters with 3-dB fractional bandwidths greater than 20 percent tend to be difficult to fabricate. A new coupling structure for filter design is proposed by M.K. Mandal, P. Mondal, S. Sanyal, and A. Chakrabarty from the Indian Institute of Technology (Kharagpur, India). This compact bandpass-filter design uses only...  — Nancy Friedrich

[Application Notes]
Electronic Line Stretchers Simplify VCO Measurements
Voltage-controlled oscillators (VCOs) are usually designed to operate in an ideal 50-Ω environment. These oscillators often have to drive a much different load, however. When the VCO output encounters a load with 12-dB return loss for all possible phase angles, it generally suffers frequency variations that must then be measured. When this measurement is performed manually, it is quite time consuming. In a two-page white paper titled, "Line Stretchers Ease VCO ...  — Nancy Friedrich

[Application Notes]
FPGAs Welcome Latest Wireless Applications
Wireless engineers are increasingly relying on field-programmable gate arrays (FPGAs) for their advantages in terms of power, functionality, and cost. FPGAs are particularly suitable for emerging wireless applications, which must satisfy stringent power-consumption and cost demands. Such applications include remote radio heads, pico/femto base stations, software-defined radio (SDR), and WiMAX customer premise equipment (CPE). In a white paper, Altera Corp. (San Jose, ...  — Nancy Friedrich

[Editor's Choice]
Linear Amplifier Boasts 80 W Output Power
By providing wideband operation in a compact and lightweight form, a solid-state Class AB linear power amplifier (PA) satisfies a variety of military needs. The model BM2719-80-3, which spans 20 to 1000 MHz, boasts RF output power of 80 W. Its RF gain is 50 dB ±1.5 dB. The PA's RF-input overdrive is +10 dBm. Input voltage standing wave ratio (VSWR) is 2.12:1 maximum. The device's harmonic rejection is –13 dBc. Among the other specifications for the ...  — Nancy Friedrich

[Editor's Choice]
Interconnect Techniques Reside On One Substrate
A new etchable materials capability is promising to allow circuit designers to integrate more functions and improve performance while reducing package size. Specifically, the advanced PCTF technology enables designers to combine a number of ceramic interconnect techniques on a single ceramic substrate. Using this capability, microcircuit designers can achieve the performance of thin-film products with added features like better power dissipation, ability for a direct...  — Nancy Friedrich

[Editor's Choice]
Tiny Chip Baluns Cut Insertion Loss To 0.6 dB
Multilayer chip baluns have emerged to tackle the impedance matching between equilibrium/nonequilibrium circuits in RF circuits for WiMAX communications equipment. At 1.6 X 0.8 X 0.6 mm, these multilayer baluns boast an insertion loss of 0.6 dB and bestin-class frequencies of 2.5 and 3.6 GHz. To achieve low insertion loss in a 1608 size, the baluns leverage low-temperature firing materials and a multilayer pattern. The AMB1608C 2500Z05, for example, operates from 2300 ...  — Nancy Friedrich

[Editor's Choice]
PXI RF Switches Beat 2.1 dB Insertion Loss
To help engineers optimize their RF switch networks, 11 PXI RF switches have been spawned. The modules, which target 50- and 75-Ω RF applications, include 4 X 1, terminated 4 X 1, dual 4 X 1, and 8 X 1 multiplexers as well as quad single-pole, double-throw (SPDT) and dual-terminated SPDT general-purpose configurations. All 11 modules offer insertion loss of less than 2.1 dB at the specified bandwidth. Their voltage-standing wave ratio (VSWR) is less than 1.75:1 ...  — Nancy Friedrich