The lumped-charge power MOSFET model, including parameterextraction

A fundamentally new, physically-based power MOSFET model features continuous and accurate curves for all three interelectrode capacitances. The model equations are derived from the charge stored on two internal nodes and the three external terminals. A straightforward parameter extraction technique uses the standard gate-charge plot or process data and is matched with interelectrode capacitance measurements. Simulations are in excellent agreement with measurements. The model is used to design a snubber for a flyback converter     

Coupled-mode analysis of gain and wavelength oscillation characteristics of diode laser phased arrays

The lasing wavelengths and gain characteristics of the modes of phase-locked arrays of channel-substrate-planar (CSP) lasers are presented. The gain values for the array modes are determined from complex coupling coefficients calculated using the fields of neighboring elements of the array. The computations show that for index guided lasers which have nearly planar phase fronts, the highest order array mode will be preferred. The "in phase" or fundamental mode which produces only one major lobe in the far-field radiation pattern, has the lowest modal gain of all array modes. The modal gain differential between the highest order and fundamental modes is less than 10 cm^-1for weak coupling between the elements.     

Characterization of the array modes of high-power gain-guided GaAssingle-quantum-well laser arrays

The characteristics of gain-guided GaAs single-quantum-well laser arrays, using proton bombardment to confine the current flow to 11 stripes on 9-μm centers, are described. The longitudinal-mode spectrum, the spectrally resolved far-field, and the near-field of this laser array were studied experimentally up to three times threshold current. The laser arrays are found to emit at ~10 longitudinal modes corresponding to the Fabry-Perot modes of the laser. The longitudinal spectrum is current dependent. Near threshold current, the spectrum consists of a number of longitudinal modes where only the fundamental mode of the array laser. At larger current, each of the longitudinal modes is broadened and the spectrum of each longitudinal mode consists of many individual emission lines of the array modes. For each longitudinal mode, the lowest order array mode emits at the longest wavelength and the highest order array mode emits at the shortest wavelength. The wavelength separation between neighboring array modes increases with increasing mode order. Fourteen array modes are found to emit simultaneously at three times threshold current. The experimental results are in good agreement with direct array-mode analysis based on the finite-difference method     

An accurate model for power DMOSFETs including interelectrodecapacitances

A SPICE-compatible circuit model for power MOSFETs is presented. It is based on device physics and uses a subcircuit representation. The interelectrode capacitances are modeled accurately as nonlinear functions of the applied biases. Various second-order effects relating to the gate capacitance model are discussed, and strategies are presented to include them in the model. The model parameters can be obtained from device measurements. The model is verified by comparing measured and simulated waveforms from a gate charge test circuit     

Analysis of the modal behavior of an antiguide diode laser arraywith Talbot filter

An analysis of the filtering of the array modes in a resonant optical waveguide (ROW) array of antiguides by a diffractive spatial filter (a Talbot filter) is presented. A dispersion relation is derived for the array modes, allowing the calculation of the field distribution. The filtering is analyzed by calculating the field propagation of each array mode in an array structure with a Talbot filter by means of the beam-propagation method. It is shown that an ROW array of antiguides with a Talbot filter is an effective means to achieve single in-phase mode operation with a diffraction-limited output     

半导体激光阵列“Smile”效应下快轴准直镜的装调

针对3种典型"Smile"形态的半导体激光阵列(LDA)如何装调快轴准直镜的问题,开展"Smile"条件下快轴准直实验定量研究。利用光纤近场扫描法和最小二乘法获得LDA的"Smile"值,采用Zemax非序列模式,模拟"Smile"下LDA的快轴准直。结果表明,LDA的"Smile"大小及形态分布影响准直镜装调位置,透镜光轴需要与LDA匹配,否则会造成光束质量的劣化。这为实际掌握LDA的快轴准直安装提供一种思路,为进一步集成高功率高光束质量的大功率半导体激光器提供了理论和实验基础。     

半导体激光阵列“Smile”效应下快轴准直镜的装调

针对3种典型“Smile”形态的半导体激光阵列(LDA)如何装调快轴准直镜的问题, 开展“Smile”条件下快轴准直实验定量研究。利用光纤近场扫描法和最小二乘法获得LDA的“Smile”值, 采用Zemax非序列模式, 模拟“Smile”下LDA的快轴准直。结果表明, LDA的“Smile”大小及形态分布影响准直镜装调位置, 透镜光轴需要与LDA匹配, 否则会造成光束质量的劣化。这为实际掌握LDA的快轴准直安装提供一种思路, 为进一步集成高功率高光束质量的大功率半导体激光器提供了理论和实验基础。     

The Even- and Odd-Mode Capacitance Parameters for Coupled Lines in Suspended Substrate

Static capacitance characterizations are derived for coupled thin-film conductors in the suspended substrate geometry, which includes shielded microstrip as a special case. In particular, a satisfactory treatment of closely coupled and narrow lines is obtained where, because of the dominance of the edge singularity, "mesh point" analyses are inadequate. The present work was carried through to meet the need in interactive design procedures for characterization of a general transmission geometry. For these procedures, algorithms are required that take little storage and are suitable for very rapid calculations. Capacitance formulas are derived from variational series based on conformal transformations, and these series are converted to easily evaluated finite forms. Calculation of the even- and odd-mode fringing capacitances for coupled limes is made for finite line widths assuming a periodic array of lines. The applicability of these capacitances to a single pair of lines and to finite filter arrays has been checked experimentally. Routines for lower bound values of fringing capacitances are given. Upper bound formulations validate the accuracy of the lower bound calculations.     

Mode locking of individual array modes of a gain-guidedsingle-quantum-well laser array with an external mirror

Mode locking of individual spatial lateral array modes of gain-guided GaAs single-quantum-well laser array with an external mirror is observed. The single-lobe fundamental array mode and several higher order array modes were individually selected by adjusting the external mirror. The array modes were characterized by the far-field patterns of the laser array. The corresponding spectrum consists a number of narrow longitudinal modes indicating that a single array mode was selected. These array modes were mode locked using a combination of feedback from the external mirror and sinusoidal RF modulation. The far-field patterns remained spatially constant when the RF modulation was applied. Autocorrelation pulsewidth measurements showed that the pulses have a Gaussian shape. Pulses as short as 70 ps were obtained for the lowest order array mode, where all the laser emitters were in phase, and increase with increasing array mode order     

Designing the focused and wide beam pattern in linear and planar phased‐MIMO radar considering the antennas' overlap

Phased‐array multiple‐input multiple‐output (MIMO) radar is a new method for collocated MIMO radar, benefiting from its advantages without losing the coherent processing gain considered the main feature of phased‐array radars. In this method, the whole array is divided into several overlapping subarrays; then a waveform is allocated to the antennas of each subarray, which are orthogonal to other subarray's waveforms. In order to obtain a desired beam pattern, appropriate weighting coefficients for each subarray should be designed. This study aimed to design the phased‐MIMO radar's weighting coefficient matrix in two modes: In the first mode, the aim is to design a beam pattern, which has the maximum value in direction of the desired targets. In the second mode, a desired beam pattern is defined, and the coefficients should calculated in such a way that the obtained pattern be as much as possible compatible with the desired patter. In the two modes, the design, at first, is accomplished for linear array and then is extended to the planar array. Moreover, the impact of subarrays' overlap and the power constraints is investigated. The proposed methods, in special cases, are applicable in MIMO and phased‐array radars, too.     

Estimating activation energies for multi-mode failures

In Accelerated Life Time Modeling, the goal is to estimate the activation energy and failure time distribution. Existing methods assume data sets come from just one mechanism of failure. However, in many applications, more failure modes can be involved and few data are available; hence, we have to develop a method to identify the number of failure modes and assign observations to the appropriate failure mode. We developed a methodology based on Finite Mixture models and Bayesian Model selection to identify multiple failure modes. The approach provides the probability for each observation being associated with a certain failure mode, and provides good estimates for the activation energy of each mode.     

均匀分布锁相列阵半导体激光器的微扰理论

本文从宽接触半导体激光器的简单模型出发,运用微扰理论分析了均匀分布锁相列阵半导体激光器的侧模行为。分析表明,对增益导引、折射率导引锁相列阵,器件一般以N阶模工作,但在增益导引列阵中将会出现大于N的高阶模。反折射率导引均匀分布锁相列阵可获得基侧模工作,其远场由于周期性微扰的作用表现为三瓣,能量主要集中于中心瓣上。     

Increase Output Energy and Operation Frequency of a Triboelectric Nanogenerator by Two Grounded Electrodes Approach

Triboelectric nanogenerator (TENG) generally operates using two‐electrodes to form a closed outer circuit loop without directly contacting ground. Here, a newly designed TENG, the two electrodes of which are grounded for doubling the energy output and the operation frequency, is introduced. The TENG operates in two modes: two‐channel mode in which the two electrodes are simultaneously connected to the ground, and single‐channel mode in which the two electrodes are alternately connected to the ground through a self‐triggered vibrating switch. Both modes doubles the total charges to be transported compared to the traditional ungrounded TENG. For the single‐channel TENG, about 30 current peaks with an output frequency of 50 Hz are generated in a single cycle at a motion triggering frequency of 2 Hz. The output energy at a load lower than 10 MΩ of the single‐channel TENG is enhanced, and the enhancing ratio is more than 100 at a load of 100 kΩ. The two electrodes grounded TENG provides a new strategy for effective use of the energy harvested from our living environment.     

The QoS provisioning tri-mode energy saving mechanism for EPON networks

The Ethernet passive optical network provides broadband Internet access but also consumes a lot of energy. Energy saving mechanisms using the dual-mode—Active and Sleep modes—design for optical network unit (ONU) in EPON still suffer unnecessary energy consumption, especially in asymmetric data flow such as video streaming downloading service. The Doze mode is particularly suitable for handling the asymmetric data flow since it allows the ONU’s transmitter to turn off while turning on its receiver to receive data from optical line termination (OLT). However, adding Doze mode into original dual-mode design incur a greater challenge for OLT to identify the current status of the ONU since the ONU cannot transmit any upstream message to OLT at either Doze or Sleep mode. In this paper, we propose a new QoS provisioning tri-mode energy saving scheme, by integrating the Doze mode into original dual-mode design, to allow the ONU to switch to one of the energy saving modes whenever no upstream traffic exists. A high-priority upstream packet, arriving at ONU of energy saving modes, is able to trigger the ONU back to Active mode for QoS provisioning purpose. Performance evaluation via simulation has demonstrated the effectiveness of such mechanism in various asymmetric data flow. Furthermore, we propose two additional enhanced approaches to increase the energy saving effects by deferring the triggering action of the high-priority upstream packet as well as coalescing new arrival packets during waiting time into the same scheduling cycle.     

Transfer functions of imaging mosaics utilizing the charge storage phenomena of transistor structures

Silicon phototransistors operating in the integration mode have been used in light detection and imaging systems. A solid-state imaging system employing a monolithic mosaic of 12 800n-p-nphototransistors has been developed. An analysis of the integration mode of operation of a silicon phototransistor is presented. The analysis employs a simplified equivalent circuit of a phototransistor. Three different cases are analyzed; each case differs in that the length of the readout cycle is changed. The solution to all three cases gives an output voltage directly proportional to the ratio of light plus leakage generated charge to the base-collector junction depletion layer capacitance. Analysis of phototransistor operation in a mosaic where interactions with the other phototransistors in the array are accounted for is presented. Discussion concerning the parasitic capacitances due to readout switches is given for the particular mosaic design employed.     

一种针对电容阵列的低功耗充放电方法——动态基准电平斜波充放电法

论述了一种用于主动阵列显示(如硅基液晶)的电容阵列充放电电路的降低功耗的方法,我们称之为动态基准电平斜波充放电法。这种方法利用一行电容上电平的分布特性,将一行的电容连通相互充放电,达到静电平衡,得到行平均电容。以行平均电容为基准电平,对输入信号高于行平均电平的像素进行充电,而对输入信号低于行平均电平的像素进行放电,使之达到输入信号的电平。经过计算,这种方法与一般的斜波充放电方法相比可以降低70%以上的电容充放电损耗。在头盔显示器中,由于对功耗有严格的限制,因此在头盔系统的硅基液晶显示器中采用本文所讨论的驱动方法,对于降低功耗、提高系统集成度具有重要意义。     

Capacitive design considerations for film-type and integrated circuits

A critical survey of capacitive effects in thin-film structures was made and design parameters to assess interelectrode coupling in integrated circuits were determined. By applying judiciously conformal mapping techniques, procedures and graphs were developed which permit evaluation of interfilm capacitances for many types of plane-parallel and cylindrical geometries. Representative designs of integrated circuits were analysed to demonstrate the effectiveness of these techniques.     

Test patterns for EPROMs

Detectable failure modes are clarified for each writing pattern. The write and erase modes for EPROM are expressed by six matrices. Four matrices express the failure modes in address, decoder and data input/output circuits, one expresses the write pattern and the last expresses bad bits in the memory array. Using this matrix method, it is clarified that the undetectable failure mode number in a 3/spl times/3 memory array is zero with a write pattern which is not a checker pattern. In addition, the failure detection rate in all `1' patterns is calculated to be about 30 percent (MNL=5) in the case of a 1 kbit memory array.     

A circuit simulation model for high-frequency power MOSFETs

A circuit simulation model suitable for modeling the static and dynamic switching characteristics of high-frequency power MOSFETs is reported. The model parameters were obtained from physical device layout, silicon doping, and measured electrical characteristics of power MOSFETs. Accurate voltage dependencies of the interelectrode capacitances were obtained from extensive two-dimensional device simulations. The voltage dependence of gate-drain capacitance was modeled using an analytic expression. The measured static current-voltage and transient-switching responses under resistive switching conditions are in excellent agreement with simulation results obtained from SPICE. The MOSFET subcircuit model was used to accurately predict the performance of a series-parallel resonant DC-DC converter using a multilevel system simulator