Module allocation with idle-time utilization for on-line testability

This paper presents a module allocation technique to improve on-line testability of a data path. The technique assigns multi-type operations to modules. Types of modules and count of each type of module, needed to synthesize a given scheduled data flow graph (SDFG) must be known a priori. The testing utilizes idle time of modules. The objective is to test each type of operation assigned to a module. Testing time is reduced by minimizing the number of types of operations assigned to a module. Certain operations called idle-time operations are scheduled in the SDFG and assigned to modules in their idle time to enhance testing. Ideally, one idle-time operation is required for each type of operation assigned to the module. The technique minimizes number of types of operations assigned to each module and creates sufficient idle time. Promising results are obtained on benchmark examples.     

Soft-defect detection (SDD) technique for a high-reliability CMOSSRAM

A complete data retention test of a CMOS SRAM array accomplished at room temperature using the soft-defect detection (SDD) technique is reported. The SDD technique uses a connectivity analysis and cell-array current test to detect physical open faults that can cause data retention failures. An extensive circuit analysis was made to establish the operation theory and special circuit design features required for SDD. Complete SDD circuits have been developed and implemented into a 16 K CMOS SRAM module for a 32-b microcontroller. Full operation and effectiveness of the SDD technique were verified from a special experimental 16 K CMOS RAM module with built-in defective cells. the SDD technique can accomplish not only the retention test at room temperature, but also the detection of other defects that were heretofore impractical to detect using the conventional retention test technique of high-temperature bakes and functional tests     

A soft-switched current-controlled converter for induction machinedrives

The paper proposes a current controlled inverter operating in zero voltage switching (ZVS) mode for an induction machine drive. Operation with no voltage stress in the DC link bus is achieved. Together with the soft switching operation, a fixed frequency bang-bang current control technique is also implemented to allow for an accurate shaping of sinusoidal currents to feed the motor. As a result, a ripple free torque profile in steady state operation is achieved. With the soft switching technique it is possible to operate conventional IGBTs at 40 kHz. A detailed analysis of the circuit operation is presented. The feasibility of the proposed scheme is experimentally verified on a prototype     

A new lifetime characterization technique using drain current transients in SOI material

A new technique based on the transient operation of the pseudo-MOS transistor is proposed for direct evaluation of generation lifetime and surface velocity in SOI wafers. The main advantages of the proposed technique are: (i) in situ operation (no prior processing of a transistor), (ii) set-up simplicity, (iii) fast comparison of different SOI technologies and (iv) simple identification of Si-film conductivity type. The influence of the electrical and non-electrical parameters of this technique is systematically investigated. Various SOI wafers (SIMOX and UNIBOND) are compared.     

A review of the pseudo-MOS transistor in SOI wafers: operation,parameter extraction, and applications

The pseudo-MOS transistor (Ψ-MOSFET) is a surprising and useful technique for the rapid evaluation of SOI wafers, prior to any CMOS processing. We review the static and dynamic modes of operation as well as the main models and methods for electrical parameter extraction. Selected numerical simulations are presented in order to clarify the optimal conditions of operation. Finally, practical applications are exemplified which illustrate the efficiency of the Ψ-MOSFET technique for in situ characterization of SOI technologies and processes     

Boundary operation of 2-D nonseparable linear-phase paraunitary filter banks

This paper proposes a boundary operation technique of 2-D nonseparable linear-phase paraunitary filter banks (NS-LPPUFBs) for size limitation. The proposed technique is based on a lattice structure consisting of the 2-D separable block discrete cosine transform and nonseparable support-extension processes. The bases are allowed to be anisotropic with the fixed critically subsampling, overlapping, orthogonal, symmetric, real-valued, and compact-support properties. First, the blockwise implementation is developed so that the basis images can be locally controlled. The local control of basis images is shown to maintain orthogonality. This property leads a basis termination (BT) technique as a boundary operation. The technique overcomes the drawback of NS-LPPUFBs that the popular symmetric extension method is invalid. Through some experimental results of diagonal texture coding, the significance of the BT is verified.     

Queueing model of a bi-level Markov service-system and its solutionusing recursion

The authors present a closed queueing model of a bi-level stochastic service system using a Markov process. The existence of two modes of operation in some real situations such as reliability, inventory, and production problems is outlined. A recursive solution technique is developed for computing steady-state probabilities and the relevant performance measures for such a system. A bi-level system is completely analyzed. The effect of the two modes of operation on the system performance measures is also discussed. The recursive solution technique is consistently superior to other common solution techniques with respect to computation time and memory requirement. A procedure is outlined for extension to a multi-level service system     

谐振式光纤陀螺数字闭环系统锁频技术

谐振式光纤陀螺(R-FOG)是基于Sagnac效应产生的谐振频率差来测量旋转角速率的一种新型光学传感器。利用数字调制、解调技术实现陀螺系统的闭环锁定,可以克服模拟电路的热漂移,使系统更加简单灵活。以谐振频率偏差作为研究对象,提出了基于一阶惯性环节的最简闭环锁定分析模型。利用该简化模型,对数字闭环系统中的频率反馈跟踪技术进行了研究,得到了在一定积分时间常数下环路的最佳增益系数,实现了环路的快速、稳定锁定,并在实验中得到进一步的验证。     

炮射雷达诱饵迷惑干扰使用研究

利用炮射雷达诱饵布设假目标以对抗反舰导弹作为一种新型无源干扰作战样式,其作战使用尚处于研究之中。对迷惑干扰的作战机理进行分析,建立了迷惑干扰的作战模型,结合典型作战环境对作战效能进行分析,对其具体作战使用提出建议,对迷惑式干扰使用的深入研究具有较强的借鉴意义。     

A Second-Order Dual X-/Ka-Band Frequency Selective Surface

In this letter, a new technique for designing dual-band frequency selective surfaces with arbitrary bands of operation, with second-order band-pass responses at each band of operation, is presented and experimentally verified. The technique is based on utilizing a particular topology of a second-order band-pass microwave filter and synthesizing its constituting elements using periodic structures with inductive, capacitive, or resonant type surface impedances. The result is a low-profile planar structure composed of three metal and two dielectric layers that acts as a spatial version of the dual-band microwave filter.      

Square-Root Domain Operational Simulation of LC Ladder Elliptic Filters

A technique for designing square-root domain elliptic filters that simulate the operation of the corresponding LC ladder prototypes is introduced in this paper. This is achieved by manipulating the equations that describe the operation of differentiation in such a way that only lossless integrator and weighted summation blocks are needed. The derived signal flow graph (SFG) is transposed to the corresponding one in the square-root domain using an appropriate set of operators in order to preserve the linear operation of the whole filter. In order to demonstrate the validity of the proposed technique, a third-order elliptic lowpass filter was simulated and its behavior was evaluated using an HSPICE simulator.     

SOI-DRAM circuit technologies for low power high speed multigigascale memories

This paper describes a silicon on insulator (SOI) DRAM which has a body bias controlling technique for high-speed circuit operation and a new type of redundancy for low standby power operation, aimed at high yield. The body bias controlling technique contributes to super-body synchronous sensing and body-bias controlled logic. The super-body synchronous sensing achieves 3.0 ns faster sensing than body synchronous sensing and the body-bias controlled logic realizes 8.0 ns faster peripheral logic operation compared with a conventional logic scheme, at 1.5 V in a 4 Gb-level SOI DRAM. The body-bias controlled logic also realizes a body-bias change current reduction of 1/20, compared with a bulk well-structure. A new type of redundancy that overcomes the standby current failure resulting from a wordline-bitline short is also discussed in respect of yield and area penalty     

Input match and load tank digital calibration of an inductively degenerated CMOS LNA

This paper presents a technique for independently tuning the center frequency and quality of the input match for a CMOS low noise amplifier implemented using the inductive source degenerating topology. This technique allows for the input match to be centered to the desired frequency in the presence of process shifts and parasitic elements. The complete calibration loop is presented. The implemented calibration circuits allow for fast calibration, low additional power consumption during calibration, and negligible additional power consumption during operation. In addition, the center frequency of the load tank is tuned to match the desired center frequency of operation using the same calibration loop.     

A high-power high-frequency ZCS-ZVS-PWM buck converter using afeedback resonant circuit

This paper presents a buck DC-to-DC power converter using a novel lossless commutation cell for high switching frequency and high power operation. The proposed cell consists of a main and auxiliary switches, with ZVS and ZCS switching characteristics, respectively. The power converter control using this cell is realized by the PWM technique, with constant switching frequency operation. The complete operation principles, theoretical analysis, relevant equations, state-space phase, simulation and experimental results for the buck converter are presented     

Single Photon Detection of InGaAs／InP APD Based on Gated-mode Operation at Telecom Wavelengths

Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is analyzed at communication wavelengths so that the basic operation parameters can decide properly for efficient detection of single photon. The bias voltage has related to the punch-through voltage in combining the cooling technique with synchronization to decrease the dark counts.     

A Frequency Offset Estimation Technique Based on Frequency Error Characterization for OFDM Communications on Multipath Fading Channels

A novel frequency offset estimation technique based on maximum-likelihood estimation for wireless orthogonal frequency division multiplexing communications on frequency-selective fading channels is proposed. By taking advantage of subcarrier-level differential operation and coherent error characterization, the proposed estimator based on the frequency error characteristics can effectively overcome multipath fading effects. Frequency error characterization is achieved by means of pseudonoise matched filters in the frequency direction; thus, the proposed estimation technique exploits frequency diversity without assistance in the form of accurate timing information. In addition, the proposed technique can combat the rapid time selectivity caused by a wide Doppler spread because it requires channel stationarity for only a short duration due to the exploitation of both a single preamble in its training operation and the following semiblind estimation aided from several pilot subchannels. The proposed technique can easily switch between training mode and semiblind mode by sharing the same system architecture. Extensive simulation results in conjunction with statistical analysis verify the superiority of the proposed technique     

Energy-adaptive Pulse Amplitude Modulation for IR-UWB Communications Under Renewable Energy

Impulse Radio Ultra-wideband (IR-UWB) technique has long been recognized for its unique carrierless operation as compared with other communication techniques. The simple and low-cost structure offers great advantages for self-powered embedded wireless systems, in which energy efficiency is a challenging issue due to the fact that most renewable energy sources only offer limited and unstable power supply. In this paper, we present an energy-adaptive Pulse Amplitude Modulation technique for self-powered IR-UWB based communication systems to improve data rate and or time coverage. The basic idea is derived from the fact that domain-specific information in such applications are often available; thus, by jointly exploiting the wireless channel conditions and the non-deterministic characteristics of renewable energy sources, the proposed technique dynamically adjusts the modulation level to enhance the sustainable operation under the unreliable energy supply. Simulation results demonstrate that the proposed technique achieves a much higher data rate and better time coverage than conventional UWB systems. The proposed technique is also insensitive to many practical issues such as the battery aging effect.     

Coated optical fibers for high-strength fusion splices

Suitable fiber-coated structures and a practical splice technique which are superior in both long-term reliability and splice operation efficiency in the field are required. A splice technique without using any dangerous chemical acids to remove the primary coat and coated fiber structures are proposed in this paper. With these techniques, an average strength of 0.88 GPa for bare fusion spliced fibers is obtained in the field, which is more than double the value compared with the average strength of 0.4 GPa obtained by the conventional splicing technique, which is used practically in the field. In addition, the splice time decreases to about one-third of the conventional splice time. The splice operation efficiency improvement is recognized for not only coated mono-fibers but for fiber ribbons.     

The design and analysis of a Miller-divider-based clock generator for MBOA-UWB application

A Miller-divider-based clock generator is proposed for Multi-Band OFDM Alliance (MBOA) ultrawideband (UWB) application. Employing closed-loop operation, the clock generator can produce three different carrier frequencies with negligible in-band spurs. The settling time of the proposed clock generator is analyzed based on a linear feedback system. A transistor sizing optimization technique for active inductors with a current-reusing technique is used to achieve low-power operation and area saving. Fabricated in a 0.18-/spl mu/m technology, the clock generator achieves less than 9.5-ns settling time while dissipating less than 47 mW from a 1.8-V power supply.     

Low voltage CMOS Schmitt trigger circuits

Two new low voltage Schmitt trigger circuits are presented which use a dynamic body-bias technique. The first circuit is designed for operation at 1 V. The second circuit, derived from the first circuit, is designed for operation at 0.4 V. Experimental results for the new Schmitt trigger circuits are presented.