A 45 nm 8-Core Enterprise Xeon¯ Processor

This paper describes a 2.3 Billion transistors, 8-core, 16-thread, 64-bit Xeon^? EX processor with a 24 MB shared L3 cache implemented in a 45 nm nine-metal process. Multiple clock and voltage domains are used to reduce power consumption. Long channel devices and cache sleep mode are used to minimize leakage. Core and cache recovery improve manufacturing yields and enable multiple product flavors from the same silicon die. The disabled blocks are both clock and power gated to minimize their power consumption. Idle power is reduced by shutting off the unterminated I/O links and shedding phases in the voltage regulator to improve the power conversion efficiency.     

Integral 3-D thermal, electrical and mechanical design of an automotive DC/DC converter

Power electronics is finding increasingly more applications in high temperature environments where power density is also a driving factor. The engine compartment of a passenger vehicle is one such example. In this paper, an integral thermal, electrical, and mechanical design of a high power density dc/dc converter operating in the thermally harsh automotive environment is discussed. The interactions and interdependencies between the three design disciplines are considered. It is illustrated how these interactions can be manipulated and used to an advantage in meeting the harsh temperature and high power density requirements of the automotive converter. Packaging and circuit techniques are identified that can be used to this end. Two case studies of a 2-kW 14-V/42-V dc/dc converter for application in the automotive environment are considered. The first prototype achieved a power density of 170 W/in/sup 3/ while the second prototype, operating with a higher environmental temperature achieved a power density of 120 W/in/sup 3/. The experimental structures and practical results are presented. Technology issues concerning the three-dimensional construction of the prototypes that need research attention are also identified.     

Measurement of high pulsed microwave power in free space

Resistive power heads connected to horn antennas are used to measure high pulsed microwave power density in free space. With such a unit, pulsed power densities up to 3 MW/m² have been measured in the S- and X-bands     

A 20-W stereo class-D audio output power stage in 0.6-/spl mu/m BCDMOS technology

This paper presents a highly power efficient 2/spl times/20-W class-D audio output power stage implemented in 0.6-/spl mu/m BCDMOS technology. The presented power stage is capable of driving 2/spl times/8-/spl Omega/ loads from a 20-V power supply at a power efficiency approaching 90%. Circuit details of thermal detection, over-current protection, and startup speaker click/pop are also presented. The performance of open-loop Class-D output stages are limited by the distortion mechanisms present within the power stage itself. A third-order PWM modulator was prototyped and used to dramatically improve the performance of the Class-D output stage by using feedback. The results of this work are also presented.     

Improved Direct Power Control of Grid-Connected DC/AC Converters

This paper proposes new direct power control (DPC) strategies for three-phase dc/ac converters with improved dynamic response and steady-state performance. As with an electrical machine, source and converter flux, which equal the integration of the respective source and converter voltage, are used to define active and reactive power flow. Optimization of the lookup table used in conventional DPC is outlined first so as to improve power control and reduce current distortion. Then, constant switching frequency DPC is developed where the required converter voltage vector within a fixed half switching period is calculated directly from the active and reactive power errors. Detailed angle compensation due to the finite sampling frequency and the use of an integral controller to further improve the power control accuracy are described. Both simulation and experimental results are used to compare conventional DPC and vector control, and to demonstrate the effectiveness and robustness of the proposed control strategies during active and reactive power steps, and line inductance variations.      

Performance study for a microcell hot spot embedded in CDMAmacrocell systems

The code-division multiple-access (CDMA) system can provide more capacity than other systems, and the hierarchical layer of cells is required for system design. However, the problem is whether the same radio frequency (RF) channels used in a CDMA overlayed/underlayed macrocell and microcell structure also obtain a high capacity as in the homogeneous structure. We investigate the interference of uplink and downlink from both the microcell and macrocell under a hierarchical structure. A downlink power control scheme and two power control methods for the uplink are also considered. Performance measures such as blocking probability, C/I, capacity, and service hole area are also obtained by computer simulation. Besides, some extra efforts for a microcell are also noted, such as more power need to be transmitted by a microcell base station (BS) if the same RF channels are used in the hierarchical structure. The capacities of macrocell and microcell in the overlaying/underlaying structure are limited by the uplink and downlink, respectively. With downlink power control, the microcellular capacity can be increased. However, the combination of downlink power control for the microcell and C/I uplink power control for the macrocell causes the overall system capacity to significantly increase     

Infrared imaging to map power on target for a millimeter-wave source

Infrared camera images are used to calculate the power deposited on a target by a millimeter wave source. Thin carbon-impregnated sheets of Kapton are illuminated with RF energy, and then infrared images in the 3-5 /spl mu/m band provide temperature data that is used to numerically solve the heat equation and obtain absorbed power values. Techniques to determine the electrical properties of Kapton up to 94 GHz were developed.     

Optimum transmission ranges in a direct-sequence spread-spectrummultihop packet radio network

The authors obtain the optimum transmission ranges to maximize throughput for a direct-sequence spread-spectrum multihop packet radio network. In the analysis, they model the network self-interference as a random variable which is equal to the sum of the interference power of all other terminals plus background noise. The model is applicable to other spread-spectrum schemes where the interference of one user appears as a noise source with constant power spectral density to the other users. The network terminals are modeled as a random Poisson field of interference power emitters. The statistics of the interference power at a receiving terminal are obtained and shown to be the stable distributions of a parameter that is dependent on the propagation power loss law. The optimum transmission range in such a network is of the form CK^α where C is a constant, K is a function of the processing gain, the background noise power spectral density, and the degree of error-correction coding used, and α is related to the power loss law. The results obtained can be used in heuristics to determine optimum routing strategies in multihop networks     

Density factor approach to representing impact of die power maps on thermal management

In the microelectronics industry, power has traditionally been the key driver for thermal management. Cooling solutions are typically rated in terms of their power dissipation capacity and efficiency. However, overall power is not the only parameter that affects thermal management. For instance, it is well-known that power density is also important (i.e., it is easier to cool 50 W uniformly distributed on a 20/spl times/20 mm die than the same power on a 10/spl times/10 mm die). Furthermore, even if the die size remains unchanged, nonuniform power distribution at the die level can create localized regions of high power density that require thermal management. This paper proposes a simple metric, density factor (DF/sub jx/), to be used in conjunction with power for quantifying the impact of power density on a given thermal solution. The advantages, limitations, and applicability of this metric are discussed.     

14W X波段AlGaN/GaN HEMT功率MMIC

报道了研制的SiC衬底AIGaN/GaN HEMT微带结构微波功率MMIC,芯片工艺采用凹槽栅场板结构提高AlGaN/GaNHEMTs的微波功率特性.S参数测试结果表明AlGaN/GaN HEMTs的频率特性随器件的工作电压变化显著.研制的该2级功率MMIC在9～11GHz带内30V工作,输出功率大于10W,功率增益大于12dB,带内峰值输出功率达到14.7W,功率增益为13.7dB,功率附加效率为23%,该芯片尺寸仅为2.0mm×1.1mm.与已发表的X波段AlGaN/GaN HEMT功率MMIC研制结果相比,本项工作在单位毫米栅宽输出功率和芯片单位面积输出功率方面具有优势.     

Open-loop power control error in cellular CDMA overlay systems

Adaptive power control has widely been used in DS/CDMA systems to overcome the so-called “near-far” problem. This paper studies the adaptive open-loop power control of a cellular CDMA system, which is overlaid in the downlink by a narrowband signal. The effects of downlink power allocation schemes to power control error in the presence of narrowband interference are analyzed. In order to get a minimum power control error in the CDMA overlay situations, an optimum downlink power allocation scheme is used, which works well for a wide range of signal to narrowband interference ratio     

Dynamic sleep transistor and body bias for active leakage power control of microprocessors

In order to manage the active power consumption of high-performance digital designs, active leakage control techniques are required to provide significant leakage power savings coupled with fast time constants for entering and exiting idle mode. In this paper, dynamic sleep transistors and body bias are used in conjunction with clock gating to control active leakage for a 32-bit integer execution core in 130-nm CMOS technology. Measurements on pMOS sleep transistor reveal that lowest-leakage state is reached in less than 1 /spl mu/s, resulting in 37/spl times/ reduction in leakage power, while reactivation of block is achieved in less than two clock cycles. PMOS body bias reduces leakage power by 2/spl times/ with no performance penalty, and similar reactivation time. Power measurements at 4 GHz, 1.3 V, 75/spl deg/C demonstrate 8% total power reduction using dynamic body bias and 15% power reduction using a pMOS sleep transistor, for a typical activity profile.     

Applying distributed power modules in telecom systems

The design of modern decentralized power systems in telecommunication applications are increasingly realized by using distributed DC/DC power modules. Power modules are usually characterized by high switching frequencies, which enable the use of small ferrite magnetics and ceramic capacitors to enhance the reliability, the power density, and the possibility of live insertion, all desired features in new power system designs. However, to utilize the advantages of power modules there are a number of considerations to be made in the design. These considerations are addressed focusing on telecom systems with an average power dissipation of <10 W/board, in free convection, i.e., nonforced convection, and <80 W/board, in forced convection cooled cabinets of commonly used mechanical sizes and designs for telecommunication equipment     

Power Flow Characterization of a Bidirectional Galvanically Isolated High-Power DC/DC Converter Over a Wide Operating Range

This paper studies the power flow characterization of a bidirectional galvanically isolated high-power dual active bridge dc/dc converter. In experimental tests at the University of Michigan, we have observed three phenomena, which we term as internal power transfer, phase drift, and low system efficiency, that are present under certain operating conditions. These phenomena cannot be explained by conventional power transfer analysis. The authors develop a new model, based on a detailed analysis over a short time scale, that incorporates additional parameters, including the power semiconductor voltage loss and dead time. The new power flow model may be used to explain the observed phenomena and to characterize the power flow of the converter. The model may also be used to perform accurate power flow computations over a wide operating range, thereby supporting optimal hardware design, operating range selection, and power management strategy development. Experimental results are presented to illustrate the validity of the new model.      

A 4–17 GHz Darlington Cascode Broadband Medium Power Amplifier in 0.18-$mu$ m CMOS Technology

This letter presents a broadband medium power amplifier in 0.18- $mu$m CMOS technology. The Darlington cascode topology is used to achieve wide bandwidth, flat gain and power frequency response. For wideband matching consideration, an interstage inductor and series peaking RL circuit are adopted. An output high pass matching circuit is used to maintain gain and power flatness at high frequency. The measured results show that the proposed PA demonstrates a gain of 10 dB from 4 to 17 GHz with less than 2-dB ripple, and a saturation output power of 16 to 18 dBm with PAE of better than 10% and power consumption of 306 mW. The chip size is only 0.67 mm$^{2}$ .      

低偏置电压工作的自对准InGaP/GaAs功率异质结双极晶体管

介绍L波段、低偏置电压下工作的自对准InGaP/GaAs功率异质结双极晶体管的研制.在晶体管制作过程中采用了发射极-基极金属自对准、空气桥以及减薄等工艺改善其功率特性.功率测试结果显示:当器件工作在AB类,工作频率为2GHz,集电极偏置电压仅为3V时,尺寸为2×(3μm×15μm)×12的功率管获得了最大输出功率为23dBm,最大功率附加效率为45%,线性增益为10dB的良好性能.     

Harmonic and reactive power compensation based on the generalizedinstantaneous reactive power theory for three-phase four-wire systems

This paper presents harmonic and reactive power compensation based on a generalized theory of instantaneous reactive power for three-phase power systems. This new theory gives a generalized definition of instantaneous reactive power, which is valid for sinusoidal or nonsinusoidal and balanced or unbalanced three-phase power systems with or without zero-sequence currents and/or voltages. The properties and physical meanings of the newly defined instantaneous reactive power are discussed in detail. A harmonic and reactive power compensator based on the new theory for a three-phase harmonic-distorted power system with zero-sequence components in the load current and/or source voltage is then used as an example to show harmonic and reactive power measurement and compensation using the new theory. Simulation and experimental results are presented     

电力电子技术在风光互补发电系统中的应用

风光互补路灯系统,是一种将光能和风能转化为电能并用于路灯照明的综合发电装置。阐述了如何将先进的电力电子技术运用到该系统的永磁发动机和智能控制器等重要部件上,旨在扩大风力发电的功率范围和有效利用蓄电池并延长其使用期限,从而提高整个系统的运行效率与可靠性。     

Solid-state laser pumping of 1.5-μm optical amplifiers andsources for lightwave video transmission

An optical power amplifier and a laser source are demonstrated at 1.5 μm. A diode-pumped Nd:YAG laser is used as the pumping source for an Er/Yb co-doped gain medium. The power scaling advantages of this approach are demonstrated. Up to +21 dBm of output power is obtained from the Er/Yb amplifier and up to +19 dBm is obtained from the laser source. The Er/Yb power amplifier was deployed in a 42-channel AM link with 40 km of fiber, and an optical loss budget of 18 dBm was demonstrated     

Investigating an LCL load resonant inverter for inductive power transfer applications

A inductor/capacitor/inductor load resonant inverter is investigated for inductive power transfer applications. The inverter uses a variable frequency controller and operates in discontinuous current mode. The steady state operation of this system is determined by a power flow balance between the inverter and the resonant tank. The results are used to design a system to achieve maximum power transfer.