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AUGUST 2007 | |
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August 2007 - In This Issue [Cover Story] Technique Trims VCXO Phase Noise Frequency reference standards are essential to achieving frequency accuracy and phase stability in electronic systems. Such sources require the chief characteristics of low phase noise and good frequency stability.1-13 The best oscillator performance can be expensive, however. Fortunately, a patented approach has been developed to design and optimize the performance of voltage-controlled crystal oscillators (VCXOs), even those with relative low quality-factor... — Ulrich L. Rohde , et al. [News] Crystal Oscillators Keep Time In Communications Systems Reference oscillators are the heartbeat of many electronics systems, as they are counted upon to keep precise time. It is largely due to advances in crystal oscillators that radio communications became possible and practical during World War II. Impressively, such oscillators still hail from many of the original makers in the industry, such as Bliley Electronics and MMD Components (originally Monitor). In addition, military applications remain a driving force behind... — Nancy Friedrich [News] Millimeter-Wave Components Aim For Broad Bandwidths ?Millimeter-wave frequencies offer a “new frontier” for communications. Realizing the overcrowding taking place at RF and microwave frequencies, the United States Federal Communications Commission (FCC) and other regulatory agencies have looked to higher frequencies as a way to add bandwidth and services. All that is missing is low-cost millimeter-wave components to assemble affordable communications infrastructure and user devices to take advantage of the “wide-open”... — Jack Browne [News] Microwave Legends ?In recognition of last August’s 45th anniversary of Microwaves & RF, the magazine’s editors came out with a list of the industry’s top 45 “Microwave Legends.” That list comprised the people, places, and products or technologies that had made the microwave industry what it is today. Although the Microwave Legends included many of history’s major players, such as Marconi, it also was peppered with some of today’s biggest trailblazers. With 45... — Nancy Friedrich [Design Features] Boost PA Efficiency With Digital Predistortion Power amplifiers for wireless applications are expected to provide exceptional linearity and efficiency in order to handle the complex waveforms used in modern communications systems. Rather than building RF power amplifiers with more pure performance, which adds cost, lowers efficiency and creates reliability issues, designers today can also opt for adding digital processing power with the use of digital-predistortion (DPD) techniques that can help maximize power-amplifier (PA)... — Marcus Dasilva , et al. [Design Features] CMOS Clock Approach Breaks Quartz Tradition Clock generation generally evokes images of quartz crystals and quartz-crystal oscillators. The technology has existed since before World War II and has provided reliable reference signals in communications systems around the world. If ever a technology could be considered "disruptive," it would be the one that displaced or at least provided an alternative to quartz crystals for this task. As will be shown, that technology exists and is based on the fabrication of... — Tunc Cenger [Design Features] Predict Resonances Of Shielded PCBs Shielded enclosures are commonly used as protection for microwave printed-circuit boards (PCBs). While the enclosure can guard a PCB from environmental effects, it can also alter the electrical performance of the circuit. Understanding the effects of the enclosure and how to predict them can improve the accuracy of most modern computeraided-engineering (CAE) simulation tools. As Part 1 of this two-part article series explored last month, the effects of the shielded... — Avinash Sharma [Design Features] BeO Takes The Heat In RF Transistor Packages Power-transistor packaging is not immune to the cost pressures facing commercial RF and microwave markets. RF power-transistor suppliers have long sought alternative materials to traditional insulating materials such as ceramics, including BeO. But the superior characteristics of BeO continue to make it the material of choice at the highest power levels at frequencies up to 4 GHz, especially in demanding military and aerospace pulsed power applications. BeO... — John E. Scheatzle [Product Technology] Downconverters Deliver Flexible IF Choices Frequency downconversion is the basis for virtually all RF/microwave systems, whether they are involved in commercial communications or military surveillance. Ideally, a frequency downconverter covers a full input frequency range of interest, translating these signals down to a range that can be examined by analysis equipment for test purposes or digitized by a high-speed analog-to-digital converter (ADC) for communications and demodulation purposes. A line of wideband... — Jack Browne [Product Technology] InGaP HBT Amplifiers Power WiMAX Systems Broadband wireless access (BWA) is being driven by increasing demand for streaming video and high-speed data anywhere and at any time. One of the technologies that may deliver these services is WiMAX, which has been standardized by the IEEE in both fixed and mobile formats. To power WiMAX transmitters at different frequencies, Sirenza Microdevices has developed a series of InGaP heterojunction-bipolar-transistor (HBT) power amplifiers with simple bias connections and... — Jack Browne [Product Technology] Cells Gain Boost From Antenna Diversity Cellular networks must overcome many obstacles, including buildings, trees, signal fading, and multipath effects. One solution would involve simply increasing transmit power in the face of these obstacles, but the carefully crafted communications standards that govern cellular communications networks do not allow for such frivolous increases in transmit power. And approaches such as multiple-in, multiple-out (MIMO) methods can improve cellular network performance but require... — Jack Browne [Product Technology] Unequal Dividers Channel 300 W From 380 To 2700 MHz Power must often be distributed at different levels within a system. A line of unequal power dividers from R&D Microwaves LLC (www.rdmicrowaves.com) can handle the task for many wireless systems at frequencies from 380 to 2700 MHz. Based on a patented airline structure, the dividers offer power split ratios ranging from as modest at 1:3 (a 6-dB drop in output level relative to input level) to 1:1000 (a... — Jack Browne [Editorial] Living Life Like A Microwave Legend Microwave Legends are made, not born. This year, the list of notable people, places, and things that have made their contributions to this industry has grown through the addition of five outstanding figures (see "Microwave Legends"). Each lived life with energy and conviction, sharing ideas and advances that would influence the rest of the industry for years to come. But one name not on that list, which may make its way... — Jack Browne [White Paper] Perfecting Pulsed RF Radar Measurements Pulsed RF radar signals must be accurately characterized to evaluate a radar system's performance,therefore using the right test tools is vital. Modern radar test instruments,with advances in DSP measurement technology, are able to provide even greater insight than their analog counterparts.The increased performance, flexibility, and functionality of modern instruments are especially useful when evaluating radars that use advanced pulse compression techniques and pulse... — John Barfuss [Feedback] Title Correction Thanks for the opportunity to get on the June cover. The cover and the article ("Single Chip Holds WiMAX Transceiver," June 2007, p. 96) look great. There was one error in the article that I'd like to correct. My title is actually "Director, Wireless Data Products" and not "WiMAX Business Manager" as was listed in the article's author information. Walter Lau MAXIM Integrated Products Editor's Note: Walter, thank you... — Walter Lau [Feedback] Claire Wainwright Thanks for a very nice article about my dad ("The Odyssey Of Claire Wainwright," Editorial, June 2007, p. 17). We're all very proud of him, and he would've loved this article. Wendy Swenson Claire Wainwright's oldest daughter Jack Browne responds: Thanks very much for writing, Wendy. Your father's time here was well spent and an inspiration. I just wanted to let more people know what it means to live "a good life" the way your... — Wendy Swenson [The Front End] China’s Mobile Navigation Market To Grow More Than 10-Fold By 2011 EL SEGUNDO, CA—Because of strong demand for navigation services from Chinese consumers, manufacturers in the nation are developing handsets supporting the Global Positioning System (GPS). Meanwhile, wireless service operators see navigation as a key value-added service that can help offset their declining Average Revenue Per User (ARPU). With falling Average Selling Prices (ASPs) for GPS handsets, domestic GPS handset shipments will rise to 16.5 million... — Compiled by John Curley [The Front End] Wi-Fi Muscling In On RFID’s Location-Based Services Markets NEW YORK, NY—The large and growing installed base of Wi-Fi equipment means new opportunities for using Wi-Fi in unorthodox ways. One of the most interesting is the growing trend toward using Wi-Fi to provide real-time location services (RTLS) for asset management, security, and work-in-progress tracking, which have traditionally been the province of proprietary RFID solutions. Today this market, at a mere $59 million in 2007 revenues, can be... — Compiled by John Curley [The Front End] Software-Defined Radio May Play Key Role In BWA Market DENVER, CO—With users wanting seamless access to emerging triple-play services—voice, data/Web, and video—in all of their wire-line and wireless subscriptions, broadband appears to be the next big growth market in telecommunications. And software-defined radio (SDR) stands poised to play a major role, according to a study commissioned by the SDR Forum (www.sdrforum.org), a non-profit... — Compiled by John Curley [The Front End] Kudos CLEVELAND, OH—Keithley Instruments, Inc. announced that it has received the Texas Instruments (TI) 2006 Supplier Excellence Award. The annual award honors firms whose dedication and commitment in supplying products and services meet TI's high standards for excellence. Recipients are chosen for their exemplary performance in the areas of cost, environmental responsibility, technology, responsiveness, assurance of supply, and quality. TI's management ... — Compiled by John Curley [Financial News] Mobile Business Services To See Big Profits Mobile e-mail, sales-force automation tools, mapping applications, and Internet access—these are all mobile data applications and services that make business customers more efficient and improve their work quality. According to a report from ABI Research (www.abiresearch.com), Mobile Business Applications and Services, mobile data applications and services used by business customers will generate... — Compiled by John Curley [Company News] Company News CONTRACTS Anaren, Inc.—Has received a contract valued in excess of $11.0 million dollars from Northrop Grumman Corp., located in Baltimore, MD, for Integrated Ferrite Assemblies used in the S-Band radar, which is part of the Mission Equipment for the Cobra Judy Replacement Program. The Cobra Judy Replacement Program is for long-loiter foreign ballistic missile data collection in support of the international treaty... — Compiled by John Curley [People] People Newtec announced that it has named KRIS WARREYN as vice president for worldwide sales. Prior to joining Newtec, Kris Warreyn was the general manager of the French branch of Scientific Atlanta and the sales director for Southern Europe and Africa. See Associated Figure SiGe Semiconductor—PETER L. GAMMEL to chief technology officer (CTO); formerly vice president of engineering at a venture-backed start-up... — Compiled by John Curley [Educational Meetings] Educational Meetings SHORT COURSES R.A. Wood Associates Short Courses Introductory RF and Microwaves September 10-11 (Syracuse, NY) November 5-6 (Philadelphia, PA) RF and Microwave Receiver Design September 12-14 (Syracuse, NY) November 7-9 (Philadelphia, PA) RF Power Amplifiers, Classes A-S: How the Circuits Operate, How to Design Them, and When to Use Each September 17-18... — Compiled by John Curley [R&D Roundup] Reflectarray Antenna Can Steer Main Beam To Large Angles From Broadside Microstrip reflectarray antennas promise to provide the best features of printed phased-array and parabolic reflector antennas. Such antennas comprise a feed horn, which illuminates a flat array of reflection elements. To produce a planar phase front in a desired direction, each element's reflection phase has to be adjusted within a 360-deg. range. For beam-scanning applications, the electronically tunable microstrip reflectarray technology provides advantages over an... — Nancy Friedrich [R&D Roundup] Active Cable-Mesh Main Reflector Proves Feasible Following the completion of the Atacama large-millimeter/submillimeter array (ALMA), an initiative emerged to develop a radio telescope that would provide a two-orders-of-magnitude increment in sensitivity over existing facilities at meter-to-centimeter wavelengths. To achieve this goal, a radio telescope is needed with a collecting area of up to 1 km2. A 500-meter aperture spherical telescope (FAST) has been proposed as an engineering demonstrator. The... — Nancy Friedrich [R&D Roundup] 2.4-GHz Subthreshold LNA Achieves 9.8 dB Gain Modern wireless applicationsare pushing complementary-metal-oxide-semiconductor (CMOS) devices to scale toward sub-1-µm gate lengths. For these devices to operate at higher frequencies, however, their gate-oxide thickness must be reduced and therefore operated at a lower power supply. A lot of research has been devoted to applications with a 3-V supply that is steadily reduced. Sub-1-V operation also has been investigated. Now, a 2.4-GHz sub-threshold CMOS... — Nancy Friedrich [Application Notes] All-Capacitor Pi Matching Network Utilizes Series Element’s ESL At lease two reactive elements are needed to match a lossless network to an arbitrary load. Yet two elements alone will not provide simultaneous control over the bandwidth and degree of match. Three-element matching networks, such as Pi- and Tee-networks, do provide additional control of the frequency response. In "Capacitor Pi Network for Impedance Matching," American Technical Ceramics (Huntington Station, NY) shows how to achieve a Pi configuration matching network... — Nancy Friedrich [Application Notes] TDR/TDT System Handles High-Bandwidth S-Parameter Analysis In high-speed serial communications systems, a designer usually relies on a vector network analyzer (VNA) to measure S-parameters. The VNA measures input/output reflections and transmission by sequentially applying signals at various frequencies and recording the response of the device under test (DUT). The measured values that result are a function of frequency. In contrast, recent advancements in high-speed time-domain reflectometry (TDR) and time-domain transmission... — Nancy Friedrich [Editor's Choice] Jitter Test Instrument Offers Crest Factor Above 18 dB As serial buses advance through faster edges and narrower unit intervals, more pressure is being placed on the design, compliance testing, and debug processes. The J7000 Jitter Test System promises to alter serial signal streams by injecting Gaussian noise in a way that reflects real-world signal behavior. To evaluate the performance of components and systems, the J7000 is capable of adding precise amounts of white noise to the signal stream. This process allows the... — Nancy Friedrich [Editor's Choice] Digital Radio Test Set Satisfies TETRA And P25 To stay current with varied and evolving communications standards, many digital test sets are now rooted in software-defined-radio (SDR) technology. As a result, users can easily expand and upgrade their capabilities. The 3920 Radio Test Set, for example, supports amplitude-modulation (AM) and frequency-modulation (FM) analysis as a standard feature. Optionally, however, it provides extended test capabilities for new digital-radio communication systems including TETRA... — Nancy Friedrich [Editor's Choice] Wideband Downconverter RF IC Covers 800 To 2700 MHz Many new products simultaneously target third-generation (3G), fourth-generation (4G), and WiMAX infrastructure. For example, a wideband-downconverter RF integrated circuit (RF IC) now claims to satisfy almost all wireless-infrastructure applications from 800 to 2700 MHz. The HMC334LP4E delivers a +26-dBm input third-order intercept point, 0 dB conversion gain, and a noise figure as low as 10 dB. This wideband downconverter features single-ended local-oscillator (LO)... — Nancy Friedrich [Editor's Choice] Chip Capacitors Are Valued At 10 To 220 pF At 4000 VDC Unlike standard electrolytic Capacitors, the Type EDL electric double-layer supercapacitor can actually act as a battery. By leveraging this feature, designers can avoid the environmental or hazardous-material issues associated with batteries. The 2500-VDC-rated and 4000-VDC-rated Type MCH also avoids the cracking and delaminating associated with porcelain and NPO ceramics in large SMD sizes. Its secret is to use high-Q alumina silicate (mica)/resin/epoxy construction.... — Nancy Friedrich |
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