Advanced Materials Research Vols. 317-319

Abstract: The method of evaluation of VDMOS storage failure rate is presented and explained in this paper. To obtain a large number of devices working hours in a short time, the accelerated factor k is brought into the failure rate test, from which the test time can be reduced to 1/k. In this paper, the failure rate test of VDMOS is carried out at 270 °C about 1500 hours with the accelerator factor k=21.73079. The storage lifetime of VDMOS was calculated over 10 years. The key parameters have been measured and reliability of VDMOS in ten years storage time has been evaluated.

Abstract: This research proposes a wireless RFID-based thermal bubble accelerometer design, and relates more particularly for the technology to manufacture and package it on a flexible substrate. The key technology is to integrate both a thermal bubble accelerometer and a wireless RFID antenna on the same substrate, such that the accelerometer is very convenient for fabrication and usage. In this paper the heaters as well as the thermal sensors are directly adhering on the surface of the flexible substrate without the traditional floating structure. Thus the structure is much simpler and cheaper for manufacturing, and much more reliable in large acceleration impact condition without broken. Furthermore, the molecular weight of xenon gas is much larger than carbon dioxide, thus the performance of the accelerometer will be increased. In addition, the shape of the chamber is changed as a semi-cylindrical one instead of the conventional rectangular type. Comparisons of sensitivity and response time are also made; one can see the performances of the proposed new design with either semi-cylindrical chamber or filled with xenon gas are better.

Abstract: Automatic synchronization is one of the important functions of marine power station management system. Grasping of ACB (air circuit breaker of generator) closing opportunity is the difficult and key point of automatic synchronization control. This paper offers a rapid and simple method of automatic synchronization control based on PLC and emphasizes on discussing a new method of grasping ACB closing opportunity in synchronization control. The system researched makes the best use of the computing function of PLC program and reduces the hardware as possible to improve the reliability and economical efficiency. Similar triangle principle and a new timing mode based on PLC scan cycle are adopted in grasping ACB closing opportunity. Several years of operation in training lab proved that the automatic synchronization system is reliable and steady.

Abstract: In order to describe electron transport properties in inversion layer of strained Si/Si1-xGex nMOSFETs, a new analytic electron mobility model is proposed. The model not only takes into account the effect of germanium(Ge) content on phonon scattering-limited mobility and surface roughness-limited mobility, and but also includes the degradation effect of strained Si film thickness and temperature on the device mobility. For various Ge content and a wide range of normal electric field, temperature and strained Si film thickness, the model provides good agreement with the experimental data in references. In addition, the model can be expressed using the analytical expression and can be easily included in the device simulator.

Abstract: In this letter, an alternating-direction reduced finite-difference time-domain (ADI-R-FDTD) method is presents. It is proven that the divergence relationship of electric-field and magnetic-field is non-zero even in charge-free regions, when the electric-field and magnetic-field are calculated with alternating-direction finite-difference time-domain (ADI-FDTD) method in 3 dimensions case, and the expression of the divergence relationship is derived. Based on the non-zero divergence relationship, the ADI-FDTD method is combined with the reduced finite-difference time-domain (R-FDTD) method. In the proposed method, the memory requirement of ADI-R-FDTD is reduced by1/12 of the memory requirement of ADI-FDTD averagely in 3D case. The formulation is presented and the accuracy and efficiency of the proposed method is verified by comparing the results with the conventional results.

Abstract: In this paper, a new method of ternary logic circuit design is developed. It’s proposed that two types of static ternary CMOS comparators and three types of dynamic CMOS comparators, designed by new method, with low transistor count, high speed and low power consumption. The proposed comparators are the rearrangement and reordering of transistors in the evaluation block of a dynamic cell. These ternary comparators can be used as equality comparators, mutual comparators and zero/one/two detectors, which are widely used in build in self test and memory testing.

Abstract: SiGe heterojunction structure much improves the performance of PnP HBT (heterojunction bipolar transistor), which focus on the impact of Ge component distribution in the base on the current gain and characteristic frequency . The triangular distribution in the base, including zero-doping and non-zero-doping at the starting point, will form a Ge-gradient acceleration filed for the minority carriers in the base to reduce the base transport time and increase current density and working frequency. Extend Ge to the collector region to eliminate the effect of the valence band spike barrier at the collector junction, further improving the performance of the pnp HBT. By the simulations and optimizations in this paper, the and of pnp SiGe HBT improves evidently, and the results can be referenced in the design of SiGe devices and circuits.

Abstract: With the development of semiconductor process technology and IC design technology, silicon-based filter technology continuously improved. The filter’s transmission characteristics depend on the dielectric constant, dielectric loss and substrate thickness. This paper studies the frequency response characteristics of transmission coefficient and reflection coefficient of the parallel coupled microstrip bandpass filter, in the condition of silicon-based with different thickness, loss and doped concentration, when the center frequency is 5.75 GHz.

Abstract: Based on the startup dynamics model axial flow blood pump system driven by large gap magnetic force, a method that realized optimal control in the blood pump acceleration by using VB programming was brought forward. In this method, Runge-Kutta algorithm was used to solve and analysis the model and the result that speed, flow and net head etc. time-domain curves were obtained; further more, suitable stable points in the speed curve could be found by setting threshold, and finally Hermite interpolation was used to discrete speed curve in conditions to get time constant and steps etc. speed control parameter. Relative to the old method for the speed control of blood pump, it is more accurate and controllability condition.

Abstract: The locomotive cab noise has became an important factor in good health of the drivers through analyzing noise hazards of the locomotive cab, and the noise also can reduce working efficiency, easy to produce hidden trouble on security. Use Multi-channel Noise Test and Analysis System, measure the locomotive cab noise and analyze the results of the noise test, then get the conclusions from the noise spectrum: Locomotive cab noise occurs mainly in the low frequency range and intermediate frequency range; Wheel-rail noise and cooling room noise mainly are low frequency noise; Electrical equipment of the first locomotive cab contribute a major noise. Results of this study provide the basis for the vibration and noise reduction design of the locomotive cab.