共查询到20条相似文献,搜索用时 31 毫秒
1.
Hoover R.C. Maciejewski A.A. Roberts R.G. 《IEEE transactions on image processing》2009,18(11):2562-2571
Eigendecomposition represents one computationally efficient approach for dealing with object detection and pose estimation, as well as other vision-based problems, and has been applied to sets of correlated images for this purpose. The major drawback in using eigendecomposition is the off line computational expense incurred by computing the desired subspace. This off line expense increases drastically as the number of correlated images becomes large (which is the case when doing fully general 3-D pose estimation). Previous work has shown that for data correlated on S 1 , Fourier analysis can help reduce the computational burden of this off line expense. This paper presents a method for extending this technique to data correlated on S 2 as well as SO(3) by sampling the sphere appropriately. An algorithm is then developed for reducing the off line computational burden associated with computing the eigenspace by exploiting the spectral information of this spherical data set using spherical harmonics and Wigner-D functions. Experimental results are presented to compare the proposed algorithm to the true eigendecomposition, as well as assess the computational savings. 相似文献
2.
In this paper, we have experimentally investigated the impact of lateral and vertical scaling of In0.7Ga0.3As high-electron-mobility transistors (HEMTs) onto their logic performance. We have found that reducing the In0.52Al0.48As insulator thickness results in much better electrostatic integrity and improved short-channel behavior down to a gate length of around 60 nm. Our nearly enhancement-mode 60-nm HEMTs feature VT = -0.02 V, DIBL = 93 mV/V, S = 88 mV/V, and ION/IOFF = 1.6 times104, at V DD = 0.5 V. We also estimate a gate delay of CV/I = 1.6 ps at VDD = 0.5 V. We have benchmarked these devices against state-of-the-art Si CMOS. For the same leakage current, which includes the gate leakage current, the InGaAs HEMTs exhibit 1.2times more current drive (ION) than the state-of-the-art 65-nm low-power CMOS technology at V DD = 0.5 V. 相似文献
3.
Sarun P.M. Vinu S. Shabna R. Biju A. Guruswamy P. Syamaprasad U. 《Applied Superconductivity, IEEE Transactions on》2009,19(1):35-38
The magnetic field (B ) dependence of electric field versus transport current density (E-J characteristics) of Bi1.6Pb0.5Sr2-xHoxCa1.1Cu2.1O8+delta superconductor was studied for x from 0.000 to 0.200. The behavior of supercurrent flow under magnetic fields in Ho-doped (Bi,Pb)-2212 is explained using thermally activated flux-creep. The n -value and characteristic pinning energy ( Uc) estimated from E-J characteristics show that at applied fields, the flux-lines in Ho-doped samples are in the glass-state. A correlation is observed between n -index and Jc of doped samples. The highly enhanced critical current density (Jc) and n-index in both self- and applied-fields due to Ho-doping is of great scientific and technological significance. 相似文献
4.
Cheng C.H. Lin S.H. Jhou K.Y. Chen W.J. Chou C.P. Yeh F.S. Hu J. Hwang M. Arikado T. McAlister S.P. Chin A. 《Electron Device Letters, IEEE》2008,29(8):845-847
We report Ir/TiO2/TaN metal-insulator-metal capacitors processed at only 300degC, which show a capacitance density of 28 fF/mum2 and a leakage current of 3 times 10-8 (25degC) or 6 times 10-7 (125degC) A/cm2 at -1 V. This performance is due to the combined effects of 300degC nanocrystallized high-kappa TiO2, a high conduction band offset, and high work-function upper electrode. These devices show potential for integration in future very-large-scale-integration technologies. 相似文献
5.
Mazzanti A. Andreani P. 《IEEE transactions on circuits and systems. I, Regular papers》2009,56(10):2173-2180
This paper presents a rigorous time-variant analysis of the 1/f MOS device noise upconversion into 1/f phase noise for two of the most popular parallel-coupled quadrature CMOS harmonic oscillators. Simple closed-form equations for the fundamental 1/f 3 phase-noise spectrum are derived and validated through SpectreRF simulations, proving that the two topologies display remarkably different sensitivities to the low-frequency noise sources. Based on the developed analysis, useful general design insights are also presented. 相似文献
6.
A $Q$ – $f$ Droop Curve for Facilitating Islanding Detection of Inverter-Based Distributed Generation
This paper presents a new method for islanding detection of distributed generation (DG) inverter that relies on analyzing the reactive power versus frequency (Q-f) characteristic of the DG and the islanded load. The proposed method is based on equipping the DG interface with a Q-f droop curve that forces the DG to lose its stable operation once an islanding condition occurs. A simple passive islanding detection scheme that relies on frequency relays can then be used to detect the moment of islanding. The performance of the proposed method is evaluated under the IEEE 1547 and UL 1741 antiislanding test configuration. The studies reported in this paper are based on time-domain simulations in the power systems computer-aided design (PSCAD)/EMTDC environment. The results show that the proposed technique has negligible nondetection zone and is capable of accurately detecting islanding within the standard permissible detection times. In addition, the technique proves to be robust under multiple-DG operation. 相似文献
7.
A fully differential CMOS ultrawideband low-noise amplifier (LNA) is presented. The LNA has been realized in a standard 90-nm CMOS technology and consists of a common-gate stage and two subsequent common-source stages. The common-gate input stage realizes a wideband input impedance matching to the source impedance of the receiver (i.e., the antenna), whereas the two subsequent common-source stages provide a wideband gain by exploiting RLC tanks. The measurements have exhibited a transducer gain of 22.7 dB at 5.2 GHz, a 4.9-GHz-wide B 3dB, an input reflection coefficient lower than -10.5 dB, and an input-referred 1-dB compression point of -19.7 dBm, which are in excellent agreement with the postlayout simulation results, confirming the approach validity and the design robustness. 相似文献
8.
Davies M.E. Gribonval R. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2009,55(5):2203-2214
This paper investigates conditions under which the solution of an underdetermined linear system with minimal lscrp norm, 0 < p les 1, is guaranteed to be also the sparsest one. Matrices are constructed with restricted isometry constants (RIC) delta2m arbitrarily close to 1/radic2 ap 0.707 where sparse recovery with p = 1 fails for at least one m-sparse vector, as well as matrices with delta2m arbitrarily close to one where lscr1 minimization succeeds for any m-sparse vector. This highlights the pessimism of sparse recovery prediction based on the RIC, and indicates that there is limited room for improving over the best known positive results of Foucart and Lai, which guarantee that lscr1 minimization recovers all m-sparse vectors for any matrix with delta2m < 2(3 - radic2)/7 ap 0.4531. These constructions are a by-product of tight conditions for lscrp recovery (0 les p les 1) with matrices of unit spectral norm, which are expressed in terms of the minimal singular values of 2m-column submatrices. Compared to lscr1 minimization, lscrp minimization recovery failure is shown to be only slightly delayed in terms of the RIC values. Furthermore in this case the minimization is nonconvex and it is important to consider the specific minimization algorithm being used. It is shown that when lscrp optimization is attempted using an iterative reweighted lscr1 scheme, failure can still occur for delta2m arbitrarily close to 1/radic2. 相似文献
9.
Amelifard B. Fallah F. Pedram M. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2008,16(7):851-860
Aggressive CMOS scaling results in low threshold voltage and thin oxide thickness for transistors manufactured in deep submicrometer regime. As a result, reducing the subthreshold and tunneling gate leakage currents has become one of the most important criteria in the design of VLSI circuits. This paper presents a method based on dual- V t and dual- T ox assignment to reduce the total leakage power dissipation of static random access memories (SRAMs) while maintaining their performance. The proposed method is based on the observation that read and write delays of a memory cell in an SRAM block depend on the physical distance of the cell from the sense amplifier and the decoder. Thus, the idea is to deploy different configurations of six-transistor SRAM cells corresponding to different threshold voltage and oxide thickness assignments for the transistors. Unlike other techniques for low-leakage SRAM design, the proposed technique incurs neither area nor delay overhead. In addition, it results in a minor change in the SRAM design flow. The leakage saving achieved by using this technique is a function of the values of the high threshold voltage and the oxide thickness, as well as the number of rows and columns in the cell array. Simulation results with a 65-nm process demonstrate that this technique can reduce the total leakage power dissipation of a 64 times 512 SRAM array by 33% and that of a 32 times 512 SRAM array by 40%. 相似文献
10.
《Electron Devices, IEEE Transactions on》2008,55(10):2614-2622
An ultrafast on-the-fly technique is developed to study linear drain current (I DLIN) degradation in plasma and thermal oxynitride p-MOSFETs during negative-bias temperature instability (NBTI) stress. The technique enhances the measurement resolution (ldquotime-zerordquo delay) down to 1 mus and helps to identify several key differences in NBTI behavior between plasma and thermal films. The impact of the time-zero delay on time, temperature, and bias dependence of NBTI is studied, and its influence on extrapolated safe-operating overdrive condition is analyzed. It is shown that plasma-nitrided films, in spite of having higher N density, are less susceptible to NBTI than their thermal counterparts. 相似文献
11.
The electrical characteristics of germanium p-metal-oxide-semiconductor (p-MOS) capacitor and p-MOS field-effect transistor (FET) with a stack gate dielectric of HfO2/TaOxNy are investigated. Experimental results show that MOS devices exhibit much lower gate leakage current than MOS devices with only HfO2 as gate dielectric, good interface properties, good transistor characteristics, and about 1.7-fold hole-mobility enhancement as compared with conventional Si p-MOSFETs. These demonstrate that forming an ultrathin passivation layer of TaOxNy on germanium surface prior to deposition of high-k dielectrics can effectively suppress the growth of unstable GeOx, thus reducing interface states and increasing carrier mobility in the inversion channel of Ge-based transistors. 相似文献
12.
Prefasi E. Hernandez L. Paton S. Wiesbauer A. Gaggl R. Pun E. 《Solid-State Circuits, IEEE Journal of》2009,44(10):2745-2754
The ADC shown in this paper uses an innovative sigma-delta (SigmaDelta) architecture that replaces the flash quantizer and mismatch corrected DAC of a multibit continuous time (CT) modulator by a time domain encoder similar to a PWM modulator to reduce the effective ADC area. The modulator achieves the resolution of a multibit design using single bit circuitry by concentrating most of the quantization error energy around a single frequency, which is afterwards removed, seizing the zeros of a sinc decimation filter. The non flat error spectrum is accomplished by use of two filter loops, one of which is made to operate in a self-oscillating mode. An experimental CT-SigmaDelta ADC prototype has been fabricated in 0.13 mum CMOS which implements a third order modulator with two operating modes. Measurements show an effective number of bits (ENOB) of 10 bits and 12 bits in a signal bandwidth of 17 MHz and 6.4 MHz, respectively, and a power-efficient figure of merit (FoM = Pwr/2 middot BW middot 2ENOB) of 0.48 pJ/conversion at 1.5 V supply. The active area of the ADC is 0.105 mm2. 相似文献
13.
Alatise O.M. Olsen S.H. Cowern N. O'Neill A.G. Majhi P. 《Electron Devices, IEEE Transactions on》2009,56(10):2277-2284
The short-channel performance of compressively strained Si0.77Ge0.23 pMOSFETs with HfSiOx/TiSiN gate stacks has been characterized alongside that of unstrained-Si pMOSFETs. Strained-SiGe devices exhibit 80% mobility enhancement compared with Si control devices at an effective vertical field of 1 MV middotcm-1. For the first time, the on-state drain-current enhancement of intrinsic strained-SiGe devices is shown to be approximately constant with scaling. Intrinsic strained-SiGe devices with 100-nm gate lengths exhibit 75% enhancement in maximum transconductance compared with Si control devices, using only ~20% Ge (~0.8% strain). The origin of the loss in performance enhancement commonly observed in strained-SiGe devices at short gate lengths is examined and found to be dominated by reduced boron diffusivity and increased parasitic series resistance in compressively strained SiGe devices compared with silicon control devices. The effective channel length was extracted from I- V measurements and was found to be 40% smaller in 100-nm silicon control devices than in SiGe devices having the same lithographic gate lengths, which is in good agreement with the metallurgical channel length predicted by TCAD process simulations. Self-heating due to the low thermal conductivity of SiGe is shown to have a negligible effect on the scaled-device performance. These findings demonstrate that the significant on-state performance gains of strained-SiGe pMOSFETs compared with bulk Si devices observed at long channel lengths are also obtainable in scaled devices if dopant diffusion, silicidation, and contact modules can be optimized for SiGe. 相似文献
14.
Zegaoui M. Choueib N. Harari J. Decoster D. Magnin V. Wallart X. Chazelas J. 《Photonics Technology Letters, IEEE》2009,21(19):1357-1359
This letter demonstrates a 2times2 low optical crosstalk and low power consumption switching matrix device based on carrier-induced effects on an InP substrate. The matrix device comprises two digital optical switches (DOSs) with a wide multimode Y-junction associated with a sinusoidal passive integrated optical circuit with an optimized X-crossing. The passive structure was designed using a two-dimensional beam propagation method (BPM) and the entire InP-InGaAsP-InP DOS was designed using a semivectorial three-dimensional BPM. The fabricated 2times2 InP switching matrix heterostructure with lambdag=1.3 mum exhibits optical crosstalk as low as -30.5 dB for drive current of 52 mA at 1.55-mum wavelength. Maximum crosstalk change of 4 dB is measured under optical polarization variation. 相似文献
15.
Yuanzheng Yue Yue Hao Jincheng Zhang Jinyu Ni Wei Mao Qian Feng Linjie Liu 《Electron Device Letters, IEEE》2008,29(8):838-840
We have developed a novel AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistor using a stack gate HfO2/Al2O3 structure grown by atomic layer deposition. The stack gate consists of a thin HfO2 (30-A) gate dielectric and a thin Al2O3 (20- A) interfacial passivation layer (IPL). For the 50-A stack gate, no measurable C-V hysteresis and a smaller threshold voltage shift were observed, indicating that a high-quality interface can be achieved using a Al2O3 IPL on an AlGaN substrate. Good surface passivation effects of the Al2O3 IPL have also been confirmed by pulsed gate measurements. Devices with 1- mum gate lengths exhibit a cutoff frequency (fT) of 12 GHz and a maximum frequency of oscillation (f MAX) of 34 GHz, as well as a maximum drain current of 800 mA/mm and a peak transconductance of 150 mS/mm, whereas the gate leakage current is at least six orders of magnitude lower than that of the reference high-electron mobility transistors at a positive gate bias. 相似文献
16.
《Electron Device Letters, IEEE》2008,29(6):557-560
In this letter, we report the fabrication and characterization of self-aligned inversion-type enhancement-mode In0.53Ga0.47As metal-oxide-semiconductor field-effect transistors (MOSFETs). The In0.53Ga0.47As surface was passivated by atomic layer deposition of a 2.5-nm-thick AIN interfacial layer. In0.53Ga0.47As MOS capacitors showed an excellent frequency dispersion behavior. A maximum drive current of 18.5 muA/mum was obtained at a gate overdrive of 2 V for a MOSFET device with a gate length of 20 mum. An Ion/off ratio of 104, a positive threshold voltage of 0.15 V, and a subthreshold slope of ~165 mV/dec were extracted from the transfer characteristics. The interface-trap density is estimated to be ~7-8 times 1012 cm-2 ldr eV-1 from the subthreshold characteristics of the MOSFET. 相似文献
17.
《Electron Devices, IEEE Transactions on》2009,56(1):116-125
18.
《Electron Devices, IEEE Transactions on》2008,55(11):2939-2945
19.
Metal-oxide-high-kappa dielectric-oxide-silicon capacitors and transistors are fabricated using HfO2 and Dy2O3 high-kappa dielectrics as the charge storage layer. The programming speed of Al/SiO2/Dy2O3/ SiO2/Si transistor is characterized by a DeltaV th shift of 1.0 V with a programming voltage of 12 V applied for 10 ms. As for retention properties, the Al/SiO2/Dy2O3/ SiO2/Si transistors can keep a DeltaV th window of 0.5 V for 2 times108 s. The corresponding numbers for Al/ SiO2/HfO2/SiO2/Si transistors are 100 ms and 2 times104 s, respectively. The better performance of the Al/SiO2/Dy2O3/ SiO2/Si transistors is attributed to the larger conduction band offset at the Dy2O3/SiO2 interface. 相似文献
20.
《Quantum Electronics, IEEE Journal of》2010,46(2):272-276