The hole-trapping and electron-trapping characteristics in dry oxides following various chemical cleanings have been studied using the avalanche injection method. The results indicated that hole trap density was almost the same for the chemical cleanings. Electron traps with two capture cross sections, σ, were observed. Electron traps with σ210-17 cm2 were found to be independent of the chemical cleaning, while those with σ410-19 cm2 to depend on the cleaning. Comparison with previous works indicated that electron traps with larger σ were related to Si-OH bonds. The other electron trap showed the increasing trapping rate with increasing the current density injected into oxide. This was explained by trap generation due to electron injection. A correlation between the density of generated electron traps and the amount of Al contamination on surfaces before dry oxidation was observed.

A simple method is developed to analyze a bent waveguide, which is described in the cylindrical coordinate system. By means of this method based on the Galerkin method, the sampling spacing can be chosen arbitrarily and it is possible to treat narrow beams. In addition we introduce the absorber using the graded lossy material. As this lossy absorber can remove the radiation wave from the bend, so we can use the finite computational window. The lightwaves propagating in the uniform bend of the slab waveguide and of the nonlinear slab waveguide are demonstrated.

The energy distribution and emission efficiency of electrons emitted from a superconductor-insulator-superconductor (SIS) junction have been investigated by numerical calculation adopting the free electron model. The emission efficiency of an SIS junction cold cathode was found to be about 0.3% of tunneling current flowing to the SIS junction when the energy gap voltage of superconductor was 20 meV, the work function of counter electrode 1 eV, the bias voltage 0.96 V, the thickness of the counter electrode 100 , the electric field strength between the plate and the counter electrode 106 V/m, and the relaxation time 0.01 ps. It is clear that the SIS junction cold cathode can emit electrons with sharper energy distributions at much the same efficiency as compared with a metal-insulator-metal (MIM) junction cold cathode.

A new set of self-consistent linear equations is presented for the analysis of the startup characteristics of gyrotron oscillators with an open cavity consisting of weakly irregular waveguides. Numerical results on frequency detuning and oscillation starting current for a whispering-gallery-mode gyrotron are described in which these equations were utilized. Experiments for making a check on the effectiveness of the derived equations showed that they well express the operation of gyrotrons in comparison with the linear theory using an empty cavity field as the wave field.

The effect of the externally reflected light on the mode partition characteristics of 1.3 µm Fabry-Perot laser diodes is studied experimentally and numerically. It is observed that the k-value increases monotonically with the DC bias current and the external reflection coefficient. Based on these experimental results, a numerical model to study the mode partition characteristics of laser diodes in the presence of external reflections is developed. The results calculated using this model agree well with the experimental ones. It is found that the mode partition noise is mainly caused by the interference between the light in the laser diode and the reflected light, and also by the fluctuations of the induced emission and absorption. In the time domain, their contribution to the mode partition noise is almost localized in the time region within 0.1nsec at the time when the optical pulse turns on.

A new model for a computer simulation of RF capacitive type hyperthermia has been developed by taking account of the following points. Blood flow is usually determined by many physiological parameters, but is regarded as a function of only blood temperature under some conditions. The temperature dependence of blood flow of tumors and normal tissues is assumed by referring the data obtained by Song et al. and Tanaka. The blood temperature which is elevated by externally applied power significantly affects temperatures of the body and the tumors. The transport of heat from the body surface is studied by considering air convection. These points are examined by experiments on a computer with simple phantom models and real patients. The results of simulation on the patient have shown a good agreement with clinical inspection based on CT images and a temperature of the stomach.

In this paper, a "hydrodynamic" version of the three-dimensional code HFIELDS-3D is used to achieve a detailed knowledge on the distribution of the substrate current inside a recessed-oxide MOSFET. The physical model features a temperature-dependent formulation of the impact-ionization rate, allowing non-local effects to be accounted for. The discretization strategy relies on the Box Integration scheme and uses suitable generalizations of the Scharfetter-Gummel technique for the energy-balance equation. The simulation results show that the narrow-channel effect has a different impact on drain and substrate currents. Further three-dimensional effects, such as the extra heating of the carriers at the channel edge, are demonstrated.

To realize a highly efficient small antenna, high-Tc superconductors are adopted to fabricate both a self-resonating helical radiator and a quarter-wave matching circuit. The actual gain and bandwidth measured at 478 MHz using a 1/45-wavelength radiator were respectively 1.5 dBi and 0.35%, indicating that this type of antenna has a high radiation efficiency and a fairly wide bandwidth. It is also confirmed through experiments and theoretical simulations that a decrease in the surface resistance of the radiator more effectively improves the radiation efficiency than a decrease in the surface resistance of the matching circuit.

A yellow light emitting display using neon-hydrogen-argon mixture as filling gas is presented. Strong "monochromatisation" of the emitted light is reported for the first time on the wavelength λ585.3 nm. Experimental results on the dependence of the "monochromatisation effect" is given for various pressure values and filling gas composition. It is underlined the existence of a process of selective population of the upper level 3p[1/2]0 of the transition corressponding to the wavelength 585.3 nm. The obtained results are discussed in relation with the reported results on yellow light laser in which a discharge in neon-hydrogen mixture is used for laser radiation generation at λ585.3 nm. The proposed explanation of different authors on the upper level population through radiative or dissociative recombination of neon ions is discussed and a new hypothesis is advanced for the strong monochromatisation observed in neon-hydrogen or neon-hydrogen-argon filled displays. According to this hypothesis, in the feeding process of the upper level 3p[1/2]0 are taking part the neon metastable states too. If such an assumption will come true, cyclic processes in yellow light generation might appear.

A spherical-harmonics expansion method is used to find approximate numerical solutions of the Boltzmann Transport Equation in the homogeneous case. Acoustic and optical phonon scattering, ionized impurity scattering as well as an energy band structure fitting the silicon density of states up to 2.6 eV above the conduction-band edge are used in the model. Comparisons with Monte Carlo data show excellent agreement, and prove that detailed information on the high-energy tail of the distribution function can be obtained at very low cost using this methodology.

In this letter we study the wave propagation in a diode-equipped microstrip line and show that soliton generation at microwave frequencies is possible with monolithic fabrications of such nonlinear transmission lines. We propose that this phenomenon be utilized as a new method of obtaining ultrashort electrical pulses with picosecond durations. The perdicted soliton generation has been confirmed by computer simulations based on the harmonic balance method.

This paper describes a new configuration and control method for an uninterruptible power supply (UPS) with a bidirectional cycloconverter. When commercial AC power is operating normally, the load is supplied by commercial AC power and the bidirectional cycloconverter operates as a battery charger. During interruptions of commercial AC power, the bidirectional cycloconverter operates as an inverter and supplies AC power to the load. Unlike a conventional UPS, this new configuration does not require a battery charger, so it can be small, light-weight, cost-effective, and highly efficient. The output voltage characteristics and the transient voltage drop in the output when commercial AC power fails are also discussed by numerical analysis and experiments.