ISSUE DATE: MAY 2007  OPTIONS
MTT-S Preview / Antennas

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May 2007 - In This Issue

[Cover Story]
High-VSWR Tuners Ease Device Matching To 6 GHz
Load-pull tuning systems provide tremendous insight into high-frequency devices under variable-impedance conditions. In terms of device and component optimization, for example, a loadpull tuner makes it possible to find the impedance-matching conditions for optimum transistor or amplifier output power or efficiency, of particular importance in the increasingly competitive wireless equipment market. The new, patent-pending High-Gamma-Tuner™ (HGT™) system...  — Eric Kueckels , et al.

[News]
Microwave Technology Reaches Hawaiian Shores
Honolulu, Hawaii is almost synonymous with the terms "vacation" and "rest and relaxation." But for one week in June, it will be the place where thousands of microwave engineers come to work, learn, and perhaps sneak off to one of those sandy beaches for a short break. For on June 3-8, 2007, Honolulu is the site of the 2007 International Microwave Symposium (IMS 2007). Sponsored by the Microwave Theory and Techniques Society (MTT-S) of the Institute of Electrical and...  — Jack Browne , et al.

[News]
Antennas Set Patterns For Wireless Growth
The cellular market and other wireless technologies owe their success to the constant engineering of software, materials, components, and more. One of the most important components in any wireless product is of course the antenna, as it both sends and receives the radio waves that make wireless communication possible. To make sure that this vital component can meet the needs of current and future wireless communications, a host of antenna manufacturers continue to...  — Nancy Friedrich

[News]
Test Laboratory Finds Cures For ESD Ailments
Electrostatic discharge (ESD) is not to be taken lightly. Just ask any engineer who has mishandled an RF or microwave transistor or delicate memory chip only to learn later that the device was inadvertently "fried." ESD can plague otherwise well-designed devices and circuits, although not if Dr. Brenda McCaffrey and her crew at White Mountain Labs (www.whitemountainlabs.com) can help it. Based in Phoenix,...  — Jack Browne

[Design Features]
Multiple Antennas Arm Effective MIMO Systems
Capacity is critical for the profitability of larger wireless networks, and multiple-input-multiple-output (MIMO) systems provide potentially high capacity.1 These systems use multiple antenna elements in both the transmitter and receiver to improve the capacity over single antenna topologies when operated in multipath environment. The properties of these antennas play key roles in determining the overall system performance. And, in spite of the number of...  — Kaj B. Jakobsen , et al.

[Design Features]
Protocol Dictates Requirements For RFID ICs
Growth in the RF-identification (RFID) market appears strong with sales of $1.7 billion in 2004 projected to reach $5.9 billion in 2008. This upsurge in demand is driven by the promises of next-generation RFID systems, which vow to provide non-line-of-sight readability, improved security, and reconfigurable product information. Applications include inventory tracking, prescription medication tracking and authentication, secure automobile keys, and access control for ...  — Minhong Mi, Ph.D. , et al.

[Design Features]
Achieve First-Pass LTCC Design Success With DFM
Low-temperature-cofired-ceramic (LTCC) circuit technology supports compact, multilayer designs and is now widely used in wireless applications, especially in RF modules and system-in-package (SiP) designs. It has a number of advantages over laminate technologies, although the process is similar to those used for laminated printed-circuit-board (PCB) materials. Typical advantages are lower dielectric loss, higher packaging density, and integrated/embedded passive...  — Heesoo Lee , et al.

[Design Features]
Evaluating Trimmer Capacitor Choices
Capacitors are essential circuit elements that store and supply charge on demand. With inductors and resistors, they are the building blocks of passive circuits and the supporting components for active circuits While fixed-value capacitors over a wide range of values are used in the majority of electrical circuits, it is sometimes preferable to use a component with a variable capacitance range, for example, for the purpose of experimentation or for adjusting the center...  — Scott Newman

[Design Features]
Analyze Matching Networks For Low-Noise Amplifiers
Low-noise amplifiers (LNA) set the general noise figure and sensitivity of receivers and other high-frequency systems. Although a variety of excellent low-noise transistors is currently available based on numerous process technologies, achieving good amplifier low-noise performance depends strongly on the required LNA device input impedances and the choice of impedance-matching topologies. By analyzing these choices, it should be possible to find an optimum topology ...  — Vladimir Aparin

[Design Features]
Technique Sets Standard For Balanced VNA Tests
Differential or balanced measurements performed with a vector network analyzer (VNA) are typically done with a "virtual" approach. The device under test (DUT) is stimulated with unbalanced signals as in the manner of testing single-ended devices, and the VNA mathematically transforms these unbalanced wave quantities into balanced S-parameter results.1 The approach is adequate for evaluating active or passive DUTs under small-signal (linear) conditions. But ...  — Yassen Mikhailov

[Design Features]
Mobile WiMAX Promises Portable Broadband Wireless
WiMAX may represent the "future" of wireless broadband connectivty, but it will not succeed without the support of many in the WiMAX Forum working with vendor companies. The WiMAX Forum is dedicated to making the WiMAX wireless communications standard a commercial reality and ensuring that WiMAX products will seamlessly work with each other. The promise of broadband wireless access has existed for almost as long as cellular networks. Previous efforts at providing...  — Mark W. Andrews , et al.

[Product Technology]
Spread-Spectrum Radios Hop Across 900-MHz Band
Spread-spectrum technology has long provided the military with secure communications. For almost as long, it has also fueled the growth of FreeWave Technologies (Boulder, CO), a leading supplier of long-distance, high-data-rate radios to military applications as well as customers in the oil and gas industries, the electric power industry, automated manufacturing, and even golf courses. The firm's latest series of frequency-hopped spread-spectrum radios operate in the...  — Jack Browne

[Product Technology]
Fast Frequency Synthesizers Switch Across 6400 MHz
Fast-switching frequency synthesizers play a special role in many systems that require the speed, such as automatic-test-equipment (ATE) systems, setups for antenna and radar-cross-section (RCS) measurements, and even in radar and electronic-warfare (EW) trainers. To fill those needs, longtime frequency synthesizer specialist Programmed Test Sources (Littleton, MA) has developed a variety of different solutions to 6.4 GHz. Model PTS 6400 is the company's...  — Jack Browne

[Product Technology]
Traveling-Wave Antenna Feeds Space Applications
Circularly polarized antennas serve a variety of satellite-communications applications, including geostationary satellites providing narrow-scan earth coverage. Although many antenna configurations are available for the task, a traveling-wave antenna developed by AK Electromagnetique (Les Coteaux, Quebec, Canada) provides the medium gain needed in an easy-to-manufacture microstrip design. An initial model has been built for L-band space applications from 1.52 to 1.67...  — Jack Browne

[Product Technology]
Coupling Cuts Phase Noise In Planar Resonator VCOs
Voltage-controlled oscillators (VCOs) are the tunable signal sources in a wide range of synthesizers, communications networks, test equipment, and other systems. Ideally, they provide wide tuning ranges with excellent phase-noise characteristics. The resonators in these sources can be formed in a variety of ways, including the use of ceramic and surface-acoustic-wave (SAW) materials. But such three-dimensional (3D) resonators are not conducive to integrated-circuit (IC)...  — Jack Browne

[Editorial]
An Informal Hawaiian Survey
Hawaii is no doubt one of the world's more beautiful locations. Whether it is the right spot for the microwave industry's most important technical conference and exhibition remains to be seen. An early sampling of companies based in the continental US seems to indicate a higher "drop-out rate" on the East Coast versus the West Coast for companies attending the 2007 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS) this June...  — Jack Browne

[White Paper]
The RF Power Behind Design Innovation
Power density in active devices is increasing according to the demands of transistor users. Applications in commercial wireless, avionics, broadcast, industrial, and medical systems are pushing the envelope for solid-state power, with growing requirements for higher output power levels from fewer output-stage devices. At Freescale Semiconductor, supplying high-performance radio frequency (RF) and microwave transistors for these applications is only part of the...  — Peter Aaen , et al.

[Feedback]
Survey Omission
I picked up my March edition of Microwaves & RF with much anticipation, and put it down shortly thereafter with much dismay at our omission (from the frequency-synthesizer survey, "Frequency Synthesizers Fit Many Formats," p. 33). On page 43, there is an advertisement from the company that I am willing to wager has delivered more frequency synthesizers than any of those surveyed in your article— 40,000 plus over 30 years and still...  — Michael G. Lohrer

[Feedback]
UWB Development
Thank you for printing my comments in your March issue concerning Yeap Yean Wei's article in the December 2006 issue ("Design A Simple, Low-Cost UWB Source," p. 68) and for his response to my comments as well. It seems to me that we both have similar experience with the matching problem of sources and antennas to be used in UWB technology. I am looking forward to Yeap Yean Wei's future paper in which he promised to describe the "real-world" problems and...  — Jiri Polivka

[The Front End]
India’s Wireless Industry Is Experiencing Incredible Growth
EL SEGUNDO, CA—According to a report from iSuppli Corp., India emerged in 2006 as one of the fastest-growing wireless telecom markets in the world. In 2006, the number of mobile-phone service subscribers in India grew to 149.5 million in 2006, up from 85 million in 2005. And the number of new subscribers continues at a torrid pace. Monthly mobile subscriber additions averaged 5.5 million in 2006, and exceeded 6 million per month by the end of the...  — Compiled by John Curley

[The Front End]
Mobile Broadband Grows 117 Percent
SCOTTSDALE, AZ—Shipments of mobile broadband equipment built for data services grew 117 percent year over year, according to year-end numbers in the Sky Light Research Wireless Broadband Point to Multipoint 2006 Quarterly Market Share Report. Included in the mobile broadband category are companies who make proprietary data-based mobile broadband equipment like pre802.16e, UMTS TD-CDMA, 802.20/FLASH OFDM, and OFDMA. Sky Light Research...  — Compiled by John Curley

[The Front End]
203 Million Mobile Phones Will Use Linux OS By 2012
LONDON, ENGLAND—The Linux community is assaulting the mobile-phone environment with a two-pronged attack that focuses on commercial operating-system solutions and realtime-operating-system (RTOS) replacement.In a report entitled "Mobile Linux: Bringing License-Free Operating Systems to Smartphones and Mid-Tier Devices," ABI Research (www.abiresearch.com) forecasts that by 2012, more than 127...  — Compiled by John Curley

[The Front End]
Kudos
DURHAM, NC—For contributions in the field of integrated-circuit (IC) technology, Dr. Isik C. Kizilyalli, director of technology at Nitronex, has been selected as a 2007 Fellow by the Institute of Electrical and Electronic Engineers (IEEE). At Nitronex, a developer and manufacturer of GaN RF power transistors for the commercial and broadband wireless-infrastructure market, Dr. Kizilyalli manages the process and device technology development department. The Fellows...  — Compiled by John Curley

[Financial News]
Silicon Motion Agrees To Acquire FCI
Silicon Motion Technology Corp., a fabless semiconductor company that designs, develops, and markets universally compatible, high-performance, low-power semiconductor solutions for the multimedia consumer market, announced that it has entered into a definitive agreement to acquire Future Communications IC, Inc. (FCI), a designer of RF integrated circuits (RF ICs) for mobile television and wireless communications that is based in Seoul, South Korea. Under the...  — Compiled by John Curley

[Company News]
Company News
CONTRACTS ANADIGICS, Inc.—Has entered into an investment contract with the Kunshan New and Hi-Tech Industrial Development Zone (KSND) to jointly construct a 6-in. galliumarsenide (GaAs) integrated-circuit (IC) wafer-fabrication facility (fab) for ANADIGICS, Inc. in the city of Kunshan in the Jiangsu Province in China. The purpose of this contract is for expanding the ANADIGICS wafer-fabrication capacity beyond its...  — Compiled by John Curley

[People]
People
ITerra Communications has appointed DR. AVI KATZ as president, CEO, and member of the board of directors. Dr. Katz was previously president and CEO of Intransa. He also had been CEO of Equator Technologies. See Associated Figure Zarlink Semiconductor, Inc.—DR. ADAM CHOWANIEC to the board of directors; continues as chairman of the board of directors at Tundra Semiconductor. Quantam Leap Packaging,...  — Compiled by John Curley

[Educational Meetings]
Educational Meetings
SHORT COURSES R.A. Wood Associates Short Courses Introductory RF and Microwaves June 4-5 (Boston, MA) September 10-11 (Syracuse, NY) November 5-6 (Philadelphia, PA) RF and Microwave Receiver Design June 6-8 (Boston, MA) September 12-14 (Syracuse, NY) November 7-9 (Philadelphia, PA) RF Power Amplifiers, Classes A-S: How the Circuits Operate, How to Design Them,...  — Compiled by John Curley

[R&D Roundup]
High-Impedance Electromagnetic Surface Improves Antenna Performance
High-impedance electromagnetic surface (HIS) is a new kind of artificial metallic electromagnetic structure. By not supporting propagating surface currents in the manner of conventional metallic conductors, HIS technology offers advantages to many microwave circuit and antenna applications. Chao Wang, Dun-bao Yan, and Nai-chang Yuan of China's National University of Defense Technology use an HIS structure as the antenna groundplane to suppress the propagation of surface...  — Nancy Friedrich

[R&D Roundup]
Pulse Generator Delivers 500-ps Output Pulse Width At 40-mV Amplitude
Unlike other RF systems, which use a narrowband carrier, impulse-radio-Ultra-Wide-Band (IRUWB) wireless communication is carrierless. It utilizes short pulse signals to transmit data over a very wide spectrum for short-range, high-data-rate applications. Tung-Yuan Tzou and Fu-Chiarng Chen of Taiwan's National Chiao Tung University have developed a circuit to generate a higher-order derivative Gaussian pulse for IR-UWB applications. The wide signal bandwidth...  — Nancy Friedrich

[R&D Roundup]
FSS Design Concept Uses Silicon As Switch Substrate
Usually, a frequency-selective surface (FSS) comprises one or more screens with two-dimensional periodic patterns, which are generated by a unit cell containing metallic patches or apertures. Now, a design composed of a metallic cross-dipole element connected by switches has been introduced by Pennsylvania State University's Xiaotao Liang, Douglas H. Werner, and Brian Weiner. The design is housed on an exposed silicon substrate. Because silicon's conductivity ...  — Nancy Friedrich

[Application Notes]
Amplifiers Perform Up To Standards Of WiMAX Output Devices
WiMax output devices are tested to verify the amplifier device's linearity as well as the fidelity of the signal that is being amplified. A test amplifier must boost WiMAX signals with sufficient power while maintaining original signal quality. The WiMAX signal's peak envelope power (PEP) is the main challenge. Peak power can be 18 dB above average power, requiring test amplification with a wide dynamic range. In a six-page white paper, Amplifier Research (AR) Worldwide...  — Nancy Friedrich

[Application Notes]
Subsystem Performance Is Defined For Multicarrier 3G Transceiver
Although there are potentially many benefits from a wideband-code-division-multiple-access (WCDMA) multicarrier third-generation (3G) transceiver, questions remain about whether the implementation of such a transceiver is feasible. In "Multicarrier WCDMA Feasibility," Analog Devices (Norwood, MA) strives to answer this question. The 22-page application note also tries to determine the major subsystem performance of such a transceiver. One general block...  — Nancy Friedrich

[Editor's Choice]
TCXO Delivers Stability To ±7 x 10–8
To satisfy applications that require excellent stability, almost no heat dissipation, and no warmup time, a microprocessor-controlled temperature-compensated crystal oscillator (TCXO) has been spawned. The T1220 offers oven-controlled-like frequency stability with temperature that is as good as ±7 X 10–8. Its current consumption is less than 30 mA. The operating-temperature range can be specified as wide as –50° to +95°C. With a...  — Nancy Friedrich

[Editor's Choice]
Active Doubler Includes Booster Amplifier
A new active doubler is versatile enough to be either operated in a saturated power mode or backed off for linear applications. The model XX1001-QK accepts input signals from 18 to 21 GHz and provides output signals from 36 to 42 GHz with +25 dBm output power. It rejects the fundamental frequencies by 50 dB. The active doubler includes gain control, which is achieved by adjusting the bias parameters. The device combines an active doubler with an input buffer amplifier...  — Nancy Friedrich

[Editor's Choice]
Power Dividers Extend From 380 To 2700 MHz
By leveraging a unique airline coaxial structure, a line of unequal power dividers manages to maintain a fixed split ratio over a 380-to-2700-MHz bandwidth. Ripple and insertion loss are kept to a minimum. Insertion loss, for example, is 1.36 dB for ports J1-J3 and 6 dB for ports J1-J2 for the UN-06N. For the UN-30N, it is 0.01 dB for J1-J3 and 30 dB for J1-J2. The UN-10N falls in the middle of this nine-member series with nominal insertion loss of 0.46 dB for J1-J3 ...  — Nancy Friedrich

[Editor's Choice]
55-GHz Bandpass Filter Limits Loss To 2 dB
The model F55-4V bandpass filter flaunts a 2-percent passband at 55 GHz. The filter assembly consists of four high-Q, iris-coupled waveguide cavities with optional waveguide-to-coax adapters at each end. The passband insertion loss is 2 dB. The rejection at 52.5 and 58 GHz is 30 dB minimum. This family of filters is available from 18 to 65 GHz. The input/output connectors are 1.85-mm "V" type. They are available in male or female. The orientation of the connectors can...  — Nancy Friedrich