Reader's Choice: Top Ten Viewed Articles of 2009
1. RFID: The Next Generation Auto-ID Technology by Amit Rawal, Monash University, Clayton, Victoria, Australia
March Technology Feature
RFID is expected to provide huge advantages to manufacturers by offering the tools to better plan production and respond more quickly to market demand. It will facilitate automation of inventory counts and speed shipping and receiving at the distribution level. For retailers, it will help reduce stock-outs, enable product tracking and potentially reduce theft and streamline the point of sale (POS) function.
The Massachusetts Institute of Technology has coined the phrase ‘The Internet of Things’ to describe the vision of a future where Thing-to-Thing (T2T) communication takes place. Cradle-to-grave tracking of items without human intervention—the domestic freezer re-ordering supplies directly from the supermarket and the food telling the microwave how to cook it—are the kinds of uses that are already being considered for commercial applications. Just how far RFID goes is a question of tagging economics and time.
While RFID technology offers a variety of potential benefits and advantages over current barcode technology and would eventually replace it, the technical, financial and psychological challenges have prevented it from attaining wide use in warehouse and distribution center operations. In the near future, while RFID technology strives to overcome these limitations and gain wider implementation, hybrid barcode-RFID systems will be the norm. However, taking into account the challenges and hurdles of exiting RFID technology, success will be more likely with short, well-defined and targeted projects. The 5 cents tag, as it has been called, has been widely viewed as the inflection point where wide adoption of RFID will quickly occur.
Like so many other aspects of the business world, the enormous impact of Wal-Mart’s buying power will dictate how and when consumer goods companies adopt RFID technology. Wal-Mart’s impact in the marketplace has been the major impetus for the current buzz about RFID and will spur early adoption. Wal-Mart had a similar impact when they began using barcodes in the 1980s. But Wal-Mart could not have made their decision if many other factors, such as the back-end infrastructure, cost and standard, were not already in place. Companies like Wal-Mart, Tesco, Metro Group, Target and Albertsons will not be able to scale to a trillion dollars in revenue using the limited information provided by barcodes. They have to do it with the next generation of technology, and that is going to be RFID.2,19 The early successes will not only help an organization, but they will also lay the groundwork for successful future investment in the technology.
2. The III-V vs. Silicon Battle by Darcy Poulin (formerly SiGe Semiconductor Inc.)
April Cover Story
There have been a number of important issues that have impacted the design of power amplifiers in recent years. This article has summarized several new issues, and has looked at how each affects the choice of technology for the power amplifier, particularly for PAs used with OFDM modulations. CMOS PAs are suitable for lower output powers, and require the use of digital adaptive predistortion to achieve linearity required for operation.
While GaAs HBT technology has traditionally been used for high power and high frequency power amplifiers, high performance SiGe BiCMOS power amplifiers are now competing very effectively with them. SiGe BiCMOS power amplifiers can be preferred to GaAs HBT PAs based on the availability of digital logic for serial interface control, as well as for the high levels of integration possible for front-end IC development. Consequently, GaAs HBT and GaAs PHEMT PAs will be used at progressively higher power levels and in more specialized applications. Slowly but surely, Silicon is progressing in the III-V versus Silicon battle on the power amplifier front.
3. State-of-the-Art Antenna Technology: The 2008 Antenna Applications Symposiumby Daniel Schaubert, University of Massachusetts; Jennifer Bernhard, University of Illinois; Robert Mailloux, US Air Force Research Laboratory; W. Devereux Palmer, US Army Research Office
January Cover Story
As it has been for over 50 years, the Antenna Applications Symposium, and its predecessor the Air Force Antenna Symposium, is a meeting place for antenna engineers from around the world; a place to discuss technology in the magnificent setting of Robert Allerton Park. Phased arrays are always a significant part of the program. Wide bandwidth operation and reduced manufacturing and operating costs are two areas of ongoing work. New materials and microfabrication techniques are extending the frequency range of arrays. New applications and new techniques, such as secure communication by pattern modulation, were disclosed at the symposium. Novel antenna designs are a common topic at the symposium. New designs presented in 2008 included a reconfigurable antenna using colloidal solutions inspired by the cuttlefish and several ways to control or to utilize antenna-platform interactions. The importance of electrically small antennas is evident from continuing work to improve their bandwidth and efficiency.
Metamaterials are composite structures that exhibit properties not achieved in nature. Despite the allure of these materials and despite several prototype demonstrations of exciting features, they are not yet widely used in practical antenna systems. A focus session at the 2008 symposium updated attendees on the status and challenges to using metamaterials in practical antenna systems. The Proceedings of the Antenna Applications Symposium are archived by the US Air Force as technical reports that can be retrieved from the Defense Technical Information Center. With the support of the US Air Force Research Laboratory Antenna Technology Branch at Hanscom AFB, the US Army Research Office and MITRE Corp., the Proceedings of this symposium have been archived in searchable electronic format on DVD, a copy of which is provided to each conference registrant. This portable electronic archive provides easy access to all available papers presented at the Allerton Symposium from 1952 through 2008. Abstracts are solicited annually in the spring, and are submitted to the conference web site (www.ecs.umass.edu/ece/allerton/).
4. Relationships Between Common Emitter, Common Base and Common Collector HBTs by Xiuping Li, Beijing University of Posts and Telecommunications, Beijing, P.R. China; Jianjun Gao, East China Normal University, Shanghai, P.R. China; Georg Boeck, Technische Universität, Berlin, Germany
February Technical Feature
In this article, a set of new analytical expressions for the relationship between common emitter, common base and common collector microwave HBTs is proposed. All the relationships provide a bi-directional bridge for the transformation between CE, CB and CC devices. This technique is based on the combination of an equivalent circuit model and a conventional two-port network signal/noise correlation matrix technique. The validity of the new approach is proved by comparison with measured S- and noise-parameters up to 20 GHz. A good agreement has been obtained for InP/InGaAs DHBTs with a 5 x 5 µm2 emitter area.
5. Development Report of Power FETs for Solid-state Power Amplifiers from GaAs to GaN Devices by Homayoun Ghani, Toshiba America Electronic Components Inc., Irvine, CA
May Technical Feature
GaN HEMTs are the front-runners for the next-generation of high power devices, and developers foresee applications for these devices expanding from their initial use with pulse-mode operation for radar. Toshiba estimates that GaN devices with power output two to three times that of GaAs devices, above C-band, can be achieved by developing GaN technology to its full potential. The realization of such devices will accelerate the trend of replacing electronic tubes with SSPA in the amplifier market for terrestrial communications base stations, satellite communications earth station and radar use at C- to K-band (4 to 26 GHz) frequencies.
6. 2009 GSMA Mobile World Congress: Gauging the Market by Richard Mumford
February Show Wrap-up
As can be seen the 2009 GSMA Mobile World Congress demonstrated that despite the economic downturn mobile technology is making advances to serve customers with innovative products and services. There is no doubt that this year is not going to be easy and difficult decisions will have to be made. The next 12 months will be significant and it will be interesting to see just how the industry has coped and progressed when the Congress reconvenes in 2010. Microwave Journal will aim to keep you informed.
7. The Dawn of Nano-scale System-on-Package by David Vye, Microwave Journal
February Cover Story
Multi-chip design is an evolving technology that offers faster time-to-market and lower development costs compared to single IC solutions yet can still deliver functionality and reduced size. SoP is the leading multi-chip technology today, whereby embedded passive components are approaching the 1000 components per square centimeter milestone. As process technology transitions from the micro to nano scale in the 2010 timeframe, SoP will deliver more capability in ultra-miniaturized packages. This development must occur hand-in-hand with increased capabilities in EDA design flows and simulation technologies as well as a growing knowledge of how to address the complexities of IC/package co-design among engineering teams.
8. Nonlinear Vector Network Analyzer Applications by Loren Betts, Agilent Technologies Inc
March Technical Feature
The NVNA has enabled a number of new measurement applications. Component behavior and complex signal analysis can be analyzed in the time, frequency and power domains with vector error correction applied. Memory effects can be analyzed utilizing the multi-envelope domain and the new nonlinear scattering coefficients (X-parameters) can be measured and then used for design and analysis of active components and systems.
9. Understanding Noise Parameter Measurement by Lawrence P. Dunleavy, Modelithics Inc.
February Application Note
In the following, the data taken on samples from the Mini-Circuits SAV amplifier series will be used. Figure 3 shows the picture of a device sample as mounted in a coplanar waveguide test fixture setup for RF wafer probe testing. TRL standards, fabricated with the same ground-signal-ground test interface, were used along with the NIST Multical method6 to establish the measurement reference planes at the locations indicated. These same reference planes were established for noise parameter measurements using Maury ATS software. Figure 4 shows examples of S-parameter measurement results, made on three test samples SAV-581+, using HP8510B with a TRL calibration, from 0.1 to 18 GHz. Figure 5 shows the noise parameters measured on SAV-581+ devices from 0.5 to 6 GHz. Clockwise, from upper left, are the minimum noise figure, Fmin (dB), the 50 Ω noise figure F50 (dB), Γsopt and equivalent noise resistance Rn
10. The New Power Brokers: High Voltage RF Devices by David Vye, Editor, Microwave Journal; Leonard Pelletier, Freescale Semiconductor; Steven Theeuwen, NXP Semiconductors; Dave Aichele, RFMD; Ray Crampton, Nitronex; Ray Pengelly, Cree Inc.; Brian Battaglia, HVVi Semiconductors
June Cover Story
Ever since Bell Lab physicists Shockley, Bardeen and Brattain invented the transistor, this little solid state device has been constantly evolving; leveraging the advantages of different semiconductor and process technologies and addressing an increasing number of applications once reserved for tubes. Sixty-plus years later — driven by a number of promising commercial and defense-related markets — transistors (and MMICs) specifically targeting high power applications in the RF and microwave frequency range continue to be the focus of sizable research and development.
Among the changing landscape of RF/microwave semiconductor developments, devices with material properties that can sustain high electric breakdown are of particular interest. To understand the state of the high power transistor market, we spoke to a number of leading vendors. Our discussion was mostly concerned with devices that could produce in excess of 30 W at UHF/VHF frequencies and above (up to X-band). These are the high-power transistors required for avionics, radar, EW and wireless infrastructure applications. Although these devices are also found in medical equipment, those applications will not be part of our focus in this article. The following is a summary of our correspondence.