Showing papers in "IEEE Microwave Magazine in 2006"
Journal Article•
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TL;DR: The silicon chip has been the mainstay of the electronics industry for the last 40 years and has revolutionized the way the world operates as mentioned in this paper, however, any optical solution must be based on low-cost technologies if it is to be applied to the mass market.
Abstract: The silicon chip has been the mainstay of the electronics industry for the last 40 years and has revolutionized the way the world operates. Today, a silicon chip the size of a fingernail contains nearly 1 billion transistors and has the computing power that only a decade ago would take up an entire room of servers. As the relentless pursuit of Moore's law continues, and Internet-based communication continues to grow, the bandwidth demands needed to feed these devices will continue to increase and push the limits of copper-based signaling technologies. These signaling limitations will necessitate optical-based solutions. However, any optical solution must be based on low-cost technologies if it is to be applied to the mass market. Silicon photonics, mainly based on SOI technology, has recently attracted a great deal of attention. Recent advances and breakthroughs in silicon photonic device performance have shown that silicon can be considered a material onto which one can build optical devices. While significant efforts are needed to improve device performance and commercialize these technologies, progress is moving at a rapid rate. More research in the area of integration, both photonic and electronic, is needed. The future is looking bright. Silicon photonics could provide low-cost opto-electronic solutions for applications ranging from telecommunications down to chip-to-chip interconnects, as well as emerging areas such as optical sensing technology and biomedical applications. The ability to utilize existing CMOS infrastructure and manufacture these silicon photonic devices in the same facilities that today produce electronics could enable low-cost optical devices, and in the future, revolutionize optical communications
1,479 citations
TL;DR: The PHD model as discussed by the authors is a black-box frequency-domain model that provides a foundation for measurement, modeling, and simulation of driven nonlinear systems, including compression, AM-PM, harmonics, load-pull, and timedomain waveforms.
Abstract: For more than a quarter of a century, microwave engineers have had the benefit of a foundation of mutually interacting components of measurement, modeling, and simulation to design and test linear components and systems. S-parameters are perhaps the most successful behavioral models ever. They have the powerful property that the S-parameters of individual components are sufficient to determine the S-parameters of any combination of those components. S-parameters of a component are sufficient to predict its response to any signal, provided only that the signal is of sufficiently small amplitude. We have presented the PHD modeling approach. It is a black-box frequency-domain model that provides a foundation for measurement, modeling, and simulation of driven nonlinear systems. The PHD model is very accurate for a wide variety of nonlinear characteristics, including compression, AM-PM, harmonics, load-pull, and time-domain waveforms. The PHD model faithfully represents driven nonlinear systems with mismatches at both the fundamental and harmonics. This enables the accurate simulation of distortion through cascaded chains of nonlinear components, thus providing key new design verification capabilities for RF and microwave modules and subsystems
359 citations
TL;DR: In this article, the Doherty amplifier is implemented using laterally diffused metal oxide semiconductor (LDMOS) transistors and measured using a WCDMA 4FA signal.
Abstract: In this article, we show that the Doherty amplifier is capable of delivering the stringent requirements of the base station power amplifiers. We explain the operation principles, including both linearity and efficiency improvements, and the basic circuit configuration of the amplifier. Advanced design methods to operate across wide bandwidth and improve the linearity are also described. For verification, the Doherty amplifier is implemented using laterally diffused metal oxide semiconductor (LDMOS) transistors and measured using a WCDMA 4FA signal. These results show that the Doherty amplifier is a promising candidate for base station power amplifiers with wide bandwidth, high efficiency, and linearity
291 citations
Journal Article•
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TL;DR: The state of the art in broadband antennas for emerging UWB applications is reviewed and the important issues of the broadband antenna design for UWB Applications are addressed.
Abstract: This article reviews the state of the art in broadband antennas for emerging UWB applications and addresses the important issues of the broadband antenna design for UWB applications. First, a variety of planar monopoles with finite ground planes are reviewed. Next, the roll antennas with enhanced radiation performance are outlined. After that, the planar antennas printed on PCBs are described. A directional antipodal Vivaldi antenna is also presented for UWB applications. Last, a UWB antenna for wearable applications is exemplified
165 citations
TL;DR: In this article, a preprocessing of the measured data as obtained by the LSNA is used to make nonlinear effects more visible and allow understanding of the energy transport mechanisms behind the device operation.
Abstract: Good measurements are a major step towards good modeling. However, besides these measurements, modeling a system also requires a good insight in the system behavior. Do harmonics rise above the noise floor? Must they be taken into account during modeling? Is the system essentially dynamic or static? An answer to the above questions lies in the preprocessing of the measured data as obtained by the LSNA. This technique makes nonlinear effects more visible and allows understanding of the energy transport mechanisms behind the device operation
88 citations
TL;DR: In this paper, a tutorial and review of recent developments in high-efficiency class F RF/ microwave PAs is provided, and an attempt is made to discuss the future developments of class-F RF/microwave PAs.
Abstract: This article provides a tutorial and review of recent developments in high-efficiency class F RF/ microwave PAs. The principles of class-F RF PAs are explained first. Recent progress in their theory and in design techniques is then presented. Different approaches of class-F PA designs are explained, and some examples of practical designs are illustrated. Finally, an attempt is made to discuss the future developments of class-F RF/microwave PAs.
84 citations
TL;DR: In this article, a comparison of shielding effectiveness of double-square and ring patches reflecting at 900 and 1,800 MHz is presented, based on the frequency of the electromagnetic wave and the electromagnetic properties of the shielding material.
Abstract: Electromagnetic pollution has been categorized as a new form of pollution The ability to reflect electromagnetic energy can be defined as shielding effectiveness This shielding effectiveness depends on the frequency of the electromagnetic wave and the electromagnetic properties of the shielding material This article presents a comparison of shielding effectiveness of double-square and ring patches reflecting at 900 and 1,800 MHz
68 citations
TL;DR: In this article, the authors provide an overview of close-in carrier phase noise and temperature stability of various oscillators in microwave systems, using acoustic, electromagnetic, and optical technologies.
Abstract: Stable microwave oscillators are realized based on high-quality factor resonators, which in turn are realized using acoustic, electromagnetic, and optical technologies. This article provides an overview of close-in carrier phase noise and temperature stability of various oscillators
54 citations
TL;DR: A new approach to analysis and design of feedback systems, based on the general feedback theorem (GFT), is discussed.
Abstract: Design-oriented analysis is a paradigm based on the recognition that design is the reverse of analysis, because the answer to the analysis is the start big point for design. Conventional loop or node analysis leads to a result in the form of a "high entropy expression," which is a ratio of sums of products of the circuit elements. There are many methods of D-OA, some of them little more than shortcuts or tricks. In this paper, the spotlight is on a new approach to analysis and design of feedback systems, based on the general feedback theorem (GFT) is discussed.
49 citations
TL;DR: In this paper, the combination of the traveling wave OMT device and the ultra-low-noise MMIC amplifiers has allowed the authors to develop a broadband 6-8 GHz receiver with a noise temperature of around 10 K.
Abstract: The combination of the traveling wave OMT device and the ultra-low-noise MMIC amplifiers has allowed us to develop a broadband 6-8 GHz receiver with a noise temperature of around 10 K. The combination of receiver noise and the additional noise contributions by the telescope optics gives an overall receiver temperature of around 28 K and 34 K in the two polarizations. The large collecting area of the telescope gives rise to a system equivalent flux density of around 4.5 Jy at 7 GHz
44 citations
TL;DR: The Undergraduate/Pre-Graduate Scholarship competition for the 2006 academic year was organized by the Microwave Theory and Techniques Society (MTT-S) as mentioned in this paper, with the purpose of attracting undergraduate students to the microwave/RF discipline and encouraging them to pursue graduate studies in this field.
Abstract: 2006 MTT-S Undergraduate/Pre-graduate Scholarships Announcement The Microwave Theory and Techniques Society is pleased to announce the Undergraduate/Pregraduate Scholarship competition for the 2006 academic year. The Undergraduate Scholarship program was instituted with the purpose of attracting undergraduate students to the microwave/RF discipline, and encouraging them to pursue graduate studies in this field. MTT-S awards up to ten $1500 (USD) scholarships each academic year. In addition, travel expenses are reimbursed for recipients to travel to an MTT-S-sponsored conference up to $1000 (USD) per awardee. Requirements. Applicants must be an undergraduate student in electrical engineering (or related field) at the time of application, but may be enrolled in his/her final year of the undergraduate program, first year of graduate studies, or combined B.S./M.S. program during the academic year for which the scholarship is awarded. Selection criteria include academic performance, a proposal for project work and career goals in the microwave/RF area and a faculty mentor recommendation. There are no U.S. citizenship requirements; awards are distributed globally. The applicants must be IEEE student members and their faculty mentors must be IEEE MTT-S Members. The deadline for applications is typically May 1st of the award cycle year. Awardees are selected by a team of experts who are also MTT Society members. More details are available from the IEEE MTT-S Web page at http://www. mtt.org—click on Awards > Undergraduate Scholarships; or contact Prof. Rhonda Franklin Drayton at drayton@umn.edu Professor Drayton chairs the Undergraduate/Pre-Graduate Scholarship program on behalf of the MTT-S AdCom Education Subcommittee.
TL;DR: In this article, an asymmetric broadside-coupled microstrip TLT (transmission line transformer) on the GaAs substrate is presented. But the matching network can be easily implemented using any monolithic microwave integrated circuit (MMIC) process supporting multilevel metallization
Abstract: Most microwave circuits and antennas use impedance transformers. In a conventional power amplifier, large number of inductors and capacitor or transmission line sections are use to realize an impedance transformer. This article presents an asymmetric broadside-coupled microstrip TLT (transmission line transformer) on the GaAs substrate. This matching network can be easily implemented using any monolithic microwave integrated circuit (MMIC) process supporting multilevel metallization
TL;DR: In this paper, the authors present two different approaches to market analysis, one starting from the efficient market approximation and the lognormal price model, and the other starting with the assumption that market sentiment should not be neglected and proceeds to develop the tools of technical analysis.
Abstract: This column returns to the topic of investment engineering. Previous columns on this topic have established the following foundation: a) a block diagram view of investment engineering; b) the lognormal model of price behavior; c) the efficient market approximation; d) the nonideal behavior of real markets. The remainder of the series will present two different approaches to market analysis. One starts from the efficient market approximation and the lognormal price model. It then derives results of practical importance, including modern portfolio theory (MPT) and options pricing theory (OPT). The other starts with the assumption that market sentiment should not be neglected and proceeds to develop the tools of technical analysis (TA). This column provides an introduction to MPT
TL;DR: In this article, the authors provide explanations for some of the anomalous phenomena commonly observed in the measurement of PAs and show how modern stability analysis techniques, based on harmonic balance, can accurately predict the undesired behavior.
Abstract: The objective of this article is to provide explanations for some of the anomalous phenomena commonly observed in the measurement of PAs It will also show how modern stability-analysis techniques, based on harmonic balance, can accurately predict the undesired behavior The article introduces practical simulation tools, applicable on both in-house and commercial harmonic balance simulators The identification of the mechanisms behind the different instability phenomena will lead to an efficient derivation of accurate techniques for their elimination from the amplifier response For illustration, the simulation tools will be applied to a Class E/F amplifier, which showed oscillations, hysteresis, and chaos (Jeon et al, 2005) Using these tools, the amplifier will be globally stabilized for all the expected operating values of the bias voltage and input power This will be achieved with negligible degradation of the amplifier performance in terms of output power and drain efficiency
TL;DR: In this paper, the authors point out a conceptual link between an artistic creation by the well-known Dutch artist M.C. Escher (1898-1972), called Circle Limit IV (woodcut, 1960), and the most commonly used graphical aid in microwave engineering work, called the Smith chart (1939-1944), created by the U.S. engineer P.H. Smith (1905-1987).
Abstract: The purpose of this article is to point out a conceptual link between an artistic creation by the well-known Dutch artist M.C. Escher (1898-1972), called Circle Limit IV (woodcut, 1960), and the most commonly used graphical aid in microwave engineering work, called the Smith chart (1939-1944), created by the U.S. engineer P.H. Smith (1905-1987)
TL;DR: In this article, the authors describe useful, practical methods for balanced circuit characterization, particularly differential voltage, common mode rejection (CMR), insertion loss, and differential impedance based on measuring two-port S-parameters.
Abstract: This article was written to help practicing RF engineers solve everyday tasks related to differential circuit characterization with precise and reliable methods, which employ ordinary single-ended two-port vector network analyzers. The article describes useful, practical methods for balanced circuit characterization, particularly differential voltage, common-mode rejection (CMR), insertion loss, and differential impedance based on measuring two-port S-parameters
TL;DR: In this article, the authors discuss the IEEE standard in radio frequency exposure and examine some of the more salient aspects applicable to mobile communication and plan to cover the other differences at a future date.
Abstract: This column discusses the new IEEE standard in radio frequency exposure. This column examines some of the more salient aspects applicable to mobile communication. The author plans to cover the other differences at a future date.
TL;DR: In this paper, the authors discuss the recent DARPA presolicitation notice in the area of hybrid insect microelectromechanical systems (MEMs), and the goal is to fund promising interdisciplinary research that will permit the creation of "insect-cyborgs".
Abstract: The article talks about recent Defense Research Projects Agency (DARPA) presolicitation notice in the area of hybrid insect micro-electromechanical systems (MEMs). DARPA's goal is to fund promising interdisciplinary research that will permit the creation of "insect-cyborgs"
TL;DR: In this paper, a measurement-based method for connector characterization is proposed, which is exact in the sense that its theoretical foundation uses no approximations or assumptions using no approximation or assumption.
Abstract: Coaxial connectors can be used either to probe the electrical properties of microwave circuits (e.g., microstrip, stripline) or as a permanent interface to the circuit. When used as a permanent interface, connectors can degrade circuit performance unless their electrical properties are characterized and accounted for during circuit design. Although it is more common to characterize microwave devices using scattering parameters (Collin, 1966) Sij, we have chosen to utilize impedance parameters since they simplify the derivation of equations presented in this article. The proposed measurement-based method for connector characterization is exact in the sense that its theoretical foundation uses no approximations or assumptions
TL;DR: In recent years, a revolution has taken place in cardiology to bring forth a new, minimally invasive interventional procedure: microwave transcatheter ablation for cardiac arrhythmias.
Abstract: In recent years, a revolution has taken place in cardiology to bring forth a new, minimally invasive interventional procedure: microwave transcatheter ablation for cardiac arrhythmias. The development of cardiac ablation using microwave energy was reported in 1987, the same year that the initial clinical use of RF energy for the ablation of cardiac arrhythmias appeared. However, clinical trials of microwave cardiac ablation did not take place until recently. Thus, microwave cardiac ablation is a relatively new concept for clinical treatment of cardiac arrhythmias
TL;DR: The Top Amplifier Research Group in a European Team (TARGET) as discussed by the authors is a network of excellence within the Sixth Framework Programme of the European Union created for the purpose of strengthening European research in the field of microwave power amplifiers for broadband wireless access.
Abstract: This article discusses an overview of Top Amplifier Research Groups in a European Team (TARGET), a network of excellence within the Sixth Framework Programme of the European Union created for the purpose of strengthening European research in the field of microwave power amplifiers for broadband wireless access.
TL;DR: In this article, the authors presented the basic ideas of modern portfolio theory (MPT) and presented a result known as the capital asset pricing model (CAPM), which is not always easy to grasp on a first encounter but plays a central role in investment theory and practice.
Abstract: The previous column presented the basic ideas of modern portfolio theory (MPT). This column covers additional aspects of the theory and presents a result known as the capital asset pricing model (CAPM). The underlying theory is not always easy to grasp on a first encounter but is presented here because it plays a central role in investment theory and practice
TL;DR: In this article, the authors look at the causes and consequences of random price behavior and propose three distinct forms of the EMH: weak, semistrong and strong forms, which are referred to as the weak, semi-and strong forms.
Abstract: The EMH is the focus of this paper. The academic point of view is encapsulated in the efficient market hypothesis (EMH). Consideration of the first issue leads to three distinct forms of the EMH. These are referred to as the weak, semistrong and strong forms. This paper looks at some of the causes and consequences of random price behavior.
TL;DR: The European Microwave Association (EuMA) was established in 1969 and was first organized in London in 1969, then Stockholm in 1971, and Brussels in 1973 as mentioned in this paper.
Abstract: This paper reports on historical prospective on the establishment and purpose of the European Microwave Association (EuMA). The EuMC was first established in the fall of every odd year, beginning in London in 1969, then Stockholm in 1971, and Brussels in 1973. Starting with Montreux in 1974, the EuMC became an annual event and was organized with the support of a professional conference manager and combined with an exhibition of manufacturers of microwave components, systems, and test equipment.
TL;DR: In this paper, the authors report the results of test conducted to young users of cellular mobile telephones and find that the brains of children are more susceptible to the radio frequency (RF) fields emitted by cell phones than those of adults.
Abstract: Are cell phones so harmful that a cautious approach of risk management especially in relation to children should be taken? Are the brains of children more susceptible to the radio frequency (RF) fields emitted by cell phones than those of adults? Some fear any disturbance to brain activity in children could lead to impaired learning ability or behavioral problems. Moreover, any lasting biochemical effects could have important consequences, especially in the young who still have years of development ahead of them. This paper report the results of test conducted to young users of cellular mobile telephones.
TL;DR: The fundamentals of VNA calibration and the 12-term error model are reviewed and the basic short-open-load-through (SOLT) calibration technique and a simple computer-aided design (CAD)-driven program are outlined to aid in the extraction and evaluation of SOLT calibration coefficients.
Abstract: The vector network analyzer (VNA) is one of the tools most commonly used by microwave engineers for component characterization and modeling. It allows the reflection and transmission coefficients to be quickly and efficiently measured. With any VNA measurement, it is important for the engineer to know and understand the error associated with a measurement. A key component of this measurement error comes from the quality of the VNA calibration. In this article, we review the fundamentals of VNA calibration and the 12-term error model. We outline the basic short-open-load-through (SOLT) calibration technique and a simple computer-aided design (CAD)-driven program to aid in the extraction and evaluation of SOLT calibration coefficients. The CAD-driven technique is useful because it allows calibration accuracy to be efficiently evaluated over frequency. It also allows for the systematic evaluation of process variation effects on the accuracy of on-wafer-calibration (OWC)
TL;DR: In this paper, the authors argue that improving standards of living in now economically underdeveloped areas will level the playing field, and underdeveloped regions will gradually become developed, and new markets for goods and services are created, raising the possibility of increased global economic activity.
Abstract: The phenomena of outsourcing, globalization and offshoring are impacting the microwave and RF engineering community. Many of us, even if not yet directly affected, are concerned. There are considerable short-term instability as manufacturing and design capabilities shift to lower cost locations. In the long term, however, we have the prospect of greater prosperity throughout the globe. Improving standards of living in now economically underdeveloped areas will level the field, and underdeveloped areas will gradually become developed. And as prosperity increases in underdeveloped areas, new markets for goods and services is created, raising the possibility of increased global economic activity. Granted, this is a very optimistic view, but this is the outcome that we are best off encouraging.
TL;DR: In the early 1970s, researchers at Phytox Corporation of College Station were looking for an environmentally friendly solution to the weed problem. They built a prototype machine with microwave radiator that is bulky and expensive to construct as mentioned in this paper.
Abstract: In the early 1970s, researchers at Phytox Corporation of College Station were looking for an environmentally friendly solution to the weed problem. They built a prototype machine with microwave radiator that is bulky and expensive to construct. Recently, a machine with similar concept is under development in the Department of Agriculture at University of Podova, Italy. This article presents an overview of this machine for controlling weeds