Showing papers in "IEEE Circuits and Systems Magazine in 2015"
TL;DR: In this paper, the authors introduce the many challenges facing EVWPT in not only high power transfer to a moving vehicle and energy management at a utility scale, but communications in a vehicle to infrastructure (V2I) environment and management of high data rates, ultra-low latency, and dealing with communications loss in dense urban areas.
Abstract: As visionary as dynamic, or in-motion, wireless charging of electric vehicles appears the concept is well over a century old as this paper will show. This is because the concept of magnetic induction dates back to the pioneering work of physicist Michael Faraday in the early 19th century. Today wireless power transfer (WPT) is being standardized for stationary and quasi-stationary charging of electric vehicles (EV). The Society of Automotive Engineers (SAE) has undertaken the standardization of stationary charging and will make this public during 2016. In addition to this the IEEE-SA (Standards Activities) initiated standards development for EV?s in their EVWPT working group in 2012. This paper introduces the many challenges facing EVWPT in not only high power transfer to a moving vehicle and energy management at a utility scale, but communications in a vehicle to infrastructure (V2I) environment and management of high data rates, ultra-low latency, and dealing with communications loss in dense urban areas. Future concepts such as guideway powering of EV?s are presented to illustrate one technical trajectory EVWPT may take.
252 citations
TL;DR: Inductive power transfer (IPT) is now recognised as one of the?hottest? research areas in Electrical Engineering combining the EE foundation studies of electricity and magnetism with power electronics and microprocessor control as discussed by the authors.
Abstract: Inductive power transfer (IPT) is now recognised as one of the ?hottest? research areas in Electrical Engineering combining the EE foundation studies of electricity and magnetism with power electronics and microprocessor control. But this acceptance is very recent ? as recently as 20 years ago IPT was widely supposed to be completely impractical and papers on it were in very short supply. This paper describes how one research group at the University of Auckland went from power electronics and motor control to international recognition in IPT over these past 20 years. It is a simple story combining technology and people and especially people with the vision to see what can be done and how systems can be built on those principles to offer solutions to engineering problems that hitherto had no possibility of a solution. The paper covers the story in a people oriented foreword that describes the original development from serendipity to a Daifuku prototype, and then as a more conventional paper from that prototype to a wide variety of IPT systems up to the possibility of roadway at power levels of 10-30 kW or more, with high efficiency and wide tolerance to misalignment.
112 citations
TL;DR: The aim in this paper is to show this revolution by discussing interesting development in RNS and foster the innovative use of RNS for more applications by investigating how this unconventional number system can be leveraged to benefit their implementation.
Abstract: Residue Number System (RNS) is a non-weighted number system which was proposed by Garner back in 1959 to achieve fast implementation of addition, subtraction and multiplication operations in special-purpose computations. Unfortunately, RNS did not turn out as a popular alternative to two?s complement number system in those days. The rigidity of instruction set architectures of the market-dominant computers and microprocessors then has been the main barrier to sustain the development of RNS-based applications. In recent years, technological advancement in semiconductor technology has revived the interests to reconsider RNS for application-specific computing. There are at least two unique motivations which make RNS computations more attractive and applicable in modern digital signal processing applications. Firstly, the modular and distributive properties of RNS are used to achieve performance improvements especially in the emerging distributed and ubiquitous computing platforms such as cloud, wireless ad hoc networks, and applications which require tolerance against soft error. Secondly, energy efficiency becomes a key driver in the continual densification of complementary metal oxide semiconductor (CMOS) digital integrated circuits. The high degree of computational parallelism in RNS offers new degree of freedom to optimize energy performance, particularly for very long word length arithmetic such as those involved in the hardware implementation of cryptographic algorithms. Our aim in this paper is to show this revolution by discussing interesting development in RNS and foster the innovative use of RNS for more applications. Different applications of RNS are investigated to demonstrate how this unconventional number system can be leveraged to benefit their implementation.
111 citations
TL;DR: The paper concludes by outlining the research challenges pertaining to the analysis, design, prototyping, manufacturing, and initial application scenarios of the proposed software defined metamaterials (SDMs), whose attributes can be changed programmatically via a computer interface.
Abstract: This paper introduces a class of programmable metamaterials, whose electromagnetic properties can be controlled via software. These software defined metamaterials (SDMs) stem from utilizing metamaterials in combination with nanonetworks. Metamaterials are artificial structures with properties that may not be found in nature. Since their initial advent, they have inspired ground-breaking applications to a range of research topics, such as electromagnetic invisibility of objects (cloaking), radiation absorption, filtering of light and sound as well as efficient antennas for sensors and implantable communication devices in recent years. However, existing metamaterial structures are ?rigid?, i.e. they cannot be restructured once constructed. This trait limits their fabrication to some well-equipped laboratories worldwide, slows down innovation, and, most importantly, restricts their applicability to static structures only. The proposed SDMs act as ?plastic? (reconfigurable) metamaterials, whose attributes can be changed programmatically via a computer interface. This control is achieved by a network of nanomachines, incorporated into the structure of the metamaterial. The nanomachines may receive commands from the user and perform simple, yet geometrically-altering, actions on the metamaterial profile and tuning of its electromagnetic behavior. Architectural aspects, expected features and implementation issues are covered in this paper, while a suitable nanonetworking model is presented along with simulation results on its anticipated performance. The paper concludes by outlining the research challenges pertaining to the analysis, design, prototyping, manufacturing, and initial application scenarios of the proposed SDMs.
94 citations
TL;DR: Theoretical studies show a wireless power transfer paradigm with a maximum bound orders of magnitude higher than conventional near-field inductive coupling, which enables electronics to be designed at the millimeter-scale and operated at nearly any location in the body as discussed by the authors.
Abstract: Midfield wireless powering enables electronics to be designed at the millimeter-scale and operated at nearly any location in the body. Theoretical studies show a wireless power transfer paradigm with a maximum bound orders of magnitude higher than conventional near-field inductive coupling. Furthermore, higher frequency of operation for midfield coupling lends itself to miniaturization of the implant. Midfield powering experiments using an external patterned metal structure and a millimeter sized coil show significant power delivery within safe levels of tissue heating in the chest and the head of a porcine model, and will enable implantable bioelectronics to reach new levels of functionality and one day to become as ubiquitous as over-the-counter pharmaceuticals.
56 citations
TL;DR: The methods discussed in the paper can be used in the design of emerging low-power digital systems having lowest complexity at the cost of a loss in accuracy?the optimal trade-off of computational accuracy for lowest possible complexity and power.
Abstract: The DCT and the DWT are used in a number of emerging DSP applications, such as, HD video compression, biomedical imaging, and smart antenna beamformers for wireless communications and radar. Of late, there has been much interest on fast algorithms for the computation of the above transforms using multiplier-free approximations because they result in low power and low complexity systems. Approximate methods rely on the trade-off of accuracy for lower power and/or circuit complexity/chip-area. This paper provides a detailed review of VLSI architectures and CAS implementations for both DCT/DWTs, which can be designed either for higher-accuracy or for low-power consumption. This article covers both recent theoretical advancements on discrete transforms in addition to an overview of existing VLSI architectures. The paper also discusses error free VLSI architectures that provides high accuracy systems and approximate architectures that offer high computational gain making them highly attractive for real-world applications that are subject to constraints in both chip-area as well as power. The methods discussed in the paper can be used in the design of emerging low-power digital systems having lowest complexity at the cost of a loss in accuracy?the optimal trade-off of computational accuracy for lowest possible complexity and power. A complete synopsis of available techniques, algorithms and FPGA/VLSI realizations are discussed in the paper.
54 citations
TL;DR: This work presents an overview of state-of-the-art low-power receivers and relates their characteristics to requirements for different application areas, and derives guidelines for using low- power receivers instead of duty-cycled transceivers.
Abstract: In wireless sensor networks (WSNs) energy efficiency and communication reliability are often conflicting requirements. Additionally, some application areas such as industrial automation or infrastructure monitoring impose strict latency bounds. Low-power receivers power consumption) together with adapted MAC protocols have the potential to meet these diverse requirements. We present an overview of state-of-the-art low-power receivers and relate their characteristics to requirements for different application areas. We compare low-power receivers to duty-cycled transceivers and present applications depending on them. For this, we use power consumption, sensitivity, and data rate as key performance figures for low-power receivers. Based on the characteristics of the applications we derive guidelines for using low-power receivers instead of ?duty-cycled transceivers.
47 citations
TL;DR: In this paper, the authors focus on the algorithmic/architectural design approaches and review the modern packet routing algorithms and thermal managements for thermal-aware 3D NoC systems.
Abstract: The three-dimensional Network-on-Chip (3D NoC) has been proposed to solve the complex on-chip communication issues in multicore systems by using die stacking technology in recent years. However, the high integration density of the stacking dies at high operating frequency results in large power density. Furthermore, the unequal thermal conductance of different logic layers leads the 3D NoC to face a much severer thermal problem than 2D NoC. Those thermal issues may limit the performance gain of 3D integration and cause lower reliability of the 3D NoC designs. To ensure the thermal safety, the 3D NoC systems generally require a better cooling method, which can be classified into ?technological approaches? and ?algorithmic/architectural approaches.? The technological approaches work efficiently for removal of internal thermal hotspots through extra devices but results in drastically increasing fabrication cost. On the other hand, the algorithmic/architectural design approaches aim to use the approaches of intelligent packet data delivery and temperature control to maximize performance under thermal constraints. Compared with technological approaches, they can control the system temperature at much lower extra circuit/device cost. In this article, we focus on the algorithmic/architectural design approaches and review the modern packet routing algorithms and thermal managements for thermal-aware 3D NoC systems. Firstly, we introduce the thermal challenges of 3D NoC system and review the encountered design challenges. Then, recent developed techniques to handle the thermal challenges of 3D NoC systems are addressed.
41 citations
TL;DR: This article outlines the design challenges and fundamental tradeoffs of wideband receivers, and describes how they can be addressed by three circuit techniques: noise cancelling, N-path filtering and N- path mixing improving the noise figure, out-of-band linearity and harmonic-rejection capability, respectively.
Abstract: A universal wideband receiver supporting multi-band multi-standard wireless communications offers the prospective for cost reduction and flexibility improvement of next-generation handheld devices. Unlike the traditional narrowband receivers that are tailored for specific standards and are assisted by dedicated SAW filters to restrict the input signals (frequency and power), SAW-less wideband receivers are fully exposed to the dynamic spectrum conditions, stimulating circuits and systems innovation to surmount the challenges while keeping up the integration level, power and area efficiencies. This article outlines the design challenges and fundamental tradeoffs of wideband receivers, and describes how they can be addressed by three circuit techniques: noise cancelling, -path filtering and -path mixing improving the noise figure, out-of-band linearity and harmonic-rejection capability, respectively. Case studies of silicon-proven solutions representing the state-of-the-art are included, illustrating the pros and cons of different implementation and combination of such three techniques. Architecturally those wideband receivers can be classified as: i) current-mode passive-mixer receiver; ii) voltage-mode passive-mixer receiver; iii) current-mode active-mixer receiver, and iv) current-mode parallel active/passive-mixer receiver. This article should be relevant to junior designers preparing to jump-start in this evolving field, and experience designers intended to collectively compare the existing solutions before further development.
37 citations
TL;DR: The article reviews in particular the application of the affine arithmetic to complex algebra and fundamental matrix operations for the numerical frequency-domain simulation and turns out to be accurate and more efficient than traditional solutions based on Monte Carlo analysis.
Abstract: The ever-increasing impact of uncertainties in electronic circuits and systems is requiring the development of robust design tools capable of taking this inherent variability into account. Due to the computational inefficiency of repeated design trials, there has been a growing demand for smart simulation tools that can inherently and effectively capture the results of parameter variations on the system responses. To improve product performance, improve yield and reduce design cost, it is particularly relevant for the designer to be able to estimate worst-case responses. Within this framework, the article addresses the worst-case simulation of lumped and distributed electrical circuits. The application of interval-based methods, like interval analysis, Taylor models and affine arithmetic, is discussed and compared. The article reviews in particular the application of the affine arithmetic to complex algebra and fundamental matrix operations for the numerical frequency-domain simulation. A comprehensive and unambiguous discussion appears in fact to be missing in the available literature. The affine arithmetic turns out to be accurate and more efficient than traditional solutions based on Monte Carlo analysis. A selection of relevant examples, ranging from linear lumped circuits to distributed transmission-line structures, is used to illustrate this technique.
26 citations
TL;DR: The achieved larger X/Y/Z placement shows that Qi standard is also capable to fulfill the spatial freedom requirement, and indicates that Qi technology development towards spatial freedom is reported.
Abstract: ?Qi?, the wireless power transfer interface specification published by the Wireless Power Consortium (WPC), has been regarded as the wireless charging standard and widely adopted in industry since its first release in August 2010. Larger spatial freedom between the power transmitter and power receiver provides significant convenience for users and device manufacturers, and is one of the critical factors for the success of wireless charging. In this paper, the recent progress of Qi technology development towards spatial freedom is reported. The achieved larger X/Y/Z placement shows that Qi standard is also capable to fulfill the spatial freedom requirement.
TL;DR: More than 200 companies are now a members of the Wireless Power Consortium, and more than 700 different products have been certified to be compliant with the Qi interface specification as mentioned in this paper, which is the most widely used standard for wireless charging.
Abstract: In November 2008, eight companies founded an open industry group, the Wireless Power Consortium, because these companies concluded that wireless charging solutions for mobile phones could not be introduced successfully unless wireless chargers were compatible across brands. By jointly developing a wireless power interface specification,the members of the Wireless Power Consortium share the risks and the investments needed to create a market for their products. At the same time, the members of the Wireless Power Consortium compete with each other in the market. They compete for market share by providing implementations of the standard that have unique properties. The competition between the members makes sure that performance increases, cost go down, and that more applications are served with solutions tuned to specific market needs. The Wireless Power Consortium published the Qi interface specification in August 2010, together with a test specification and a certification procedure. More than 200 companies are now a members of the Wireless Power Consortium, and more than 700 different products have been certified to be compliant with the Qi interface specification. In the coming years the Wireless Power Consortium will extend the Qi interface specification by providing more choice in power levels, more choice in transfer distance, more choice in charging area, more choice in low-cost solutions, more choice in multidevice chargers, more choice in systems for automotive use, and more choice in systems for public space charging.
TL;DR: In this article, the analog power consumption of analog systems is poorly understood, in contrast to the very well developed analysis of digital power consumption, and it is shown that there is good opportunity to develop analog power understanding to a similar level as the digital.
Abstract: Power consumption of analog systems is poorly understood today, in contrast to the very well developed analysis of digital power consumption. We show that there is good opportunity to develop also the analog power understanding to a similar level as the digital. Such an understanding will have a large impact in the design of future electronic systems, where low power consumption will be crucial. Eventually we may reach a power centric analog design methodology.
TL;DR: In this article, the authors describe how electronic systems are increasingly fusing multiple technology solutions exchanging information both at electrical and at non-electrical levels, and in general both analog and digital operation coexists in multiple physical domains.
Abstract: Electronic systems are increasingly fusing multiple technology solutions exchanging information both at electrical and at non-electrical levels, and in general both analog and digital operation coexists in multiple physical domains
TL;DR: In this paper, a new direction is struck with an analysis of natural pulses propagating along a realistic model of a neural membrane, which support the efficient generation of a wide variety of dense combinational and sequential logic.
Abstract: A new direction is struck with an analysis of natural pulses propagating along a realistic model of a neural membrane. Described below are interesting neural pulses that support the efficient generation of a wide variety of dense combinational and sequential logic. Although not new, the implied circuit elements and connections are interesting and may foreshadow the future of circuit engineering.