In order to realize the “POL (Point of Load)” dc-dc converter for LSIs, a Zn-ferrite thick film planar power inductor embedded in LSI package has been fabricated and evaluated in this study. 10 μm thick spin-sprayed Zn ferrite film with a high saturation magnetization of 0.57 T was introduced to the magnetic core for planer power inductor consisting of a 20 μm thick, 650 μm square, 2-turn inner copper spiral coil sandwiched by top and bottom magnetic core. Zn ferrite film had a natural resonance frequency of 500 MHz and a static relative permeability of 80. The planar power inductor with a footprint of 850×850 μm exhibited a 10 nH inductance and a quality factor of 20 at 100 MHz. The degradation of inductance owing to the superimposed dc current of 2A was 17%. The planar power inductor will be applied to low-voltage converter with hundreds megahertz switching operation in the future.

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This paper presents an induction magnetometer with a metal shielded pickup coil for MHz range operation. The validity of two simple equivalent circuit models for voltage detection and current detection is also confirmed by experimental results. From the measured frequency response for a calibrated magnetic field of 10 nT, we successfully demonstrate the ability of the magnetometer. The experimental results reveal the quantitative data of the equivalent resistance and inductance. When the resistance of the pickup coil is quite low, the equivalent resistance can be regarded as the resistance of the BNC connector (50 Ω). With the equivalent resistance, the absolute error of the output voltage between measurement and estimation is less than ±1 dBμV between 0.3 MHz and 2 MHz. In contrast, it is found that the existence of the metal shielded layer affects the estimated equivalent inductance. If the pickup coil has no metal shielded layer, the estimated value of the equivalent inductance is 56.3 times the inductance of the pickup coil. This value is verified by the estimated and measured results. However, this phenomenon is not found if the pickup coil has the metal shielded layer.

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To increase the uniaxial- magnetic anisotropy in thin-film materials is the key issue for the micro-magnetic devices driven in a GHz frequency. It is known that an especially large uniaxial- magnetic anisotropy was induced only by the carousel sputtering method. In this paper, an atomic deposition process of the CoFeB and CoFe films were analyzed by using simulation of Kinetic Theory of Gases. The result exhibited that the sputtered particles had remarkably anisotropic incidence to the substrate leading to different atomic distances with respect to the incident direction, which results in a magnetic elastic effect. These sputtered particles with the anisotropic incidence give rise to a main cause of the higher uniaxial- magnetic anisotropy of the films.

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This paper reports the study on the damping constant α of Ni-Fe films using both one and two port type coplanar waveguide-ferromagnetic resonance (CPW-FMR) measurements, and compared these results with a conventional FMR (cavity-type FMR) measurement. In each CPW-FMR measurement, for the films thicker than 10 nm, each α becomes constant in the range of 0.012-0.014. On the other hand, for the film thickness less than 10 nm, α increases from 0.014 to 0.017 as the film thickness decreases, which may be attributed to structural inhomogeneity in the films. These results are in good agreement with those obtained from the cavity-type FMR measurement. On the basis of these results, it is pointed out that α of Ni-Fe films can be evaluated accurately by either of the CPW-FMR measurements. These results also mean that the one port type CPW-FMR measurement is more effective than the two port type CPW-FMR measurement for characterization of Ni-Fe films because the former method is simple and a stronger high frequency magnetic field can be generated.

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A highly sensitive and broadband method of obtaining the permeability of magnetic film without limitations in sample size was developed based on the high frequency impedance of microstrip meander probe and magnetic film. The probe (5.6 mm × 5 mm, 2 turns) was scanned in the vicinity of a CoNbZr thin film (50 × 50 mm, 0.1 μm thick), and the permeability was optimized by Newton-Raphson method in a frequency range of 10 MHz - 8 GHz. The measured values roughly corresponded to theoretical values based on the Landau-Lifshitz-Gilbert equation and eddy current generation. The proposed method shows promise for measuring the permeability of wafer-sized samples in-line because it is not restricted by size limitations.

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A dual composite right/left handed (D-CRLH) differential transmission line common mode filter had been proposed and reported as a new type common mode filter previously by our group. A D-CRLH differential transmission line has common mode filter function because its equivalent circuits in differential signal mode and common noise mode were different. However, our first prototype device had large insertion loss of about 8 dB. Therefore transmission characteristics of the device have been improved by improvement of device structure and optimization of its design dimension. In this paper, we descripted fundamental of D-CRLH differential transmission line as common mode filter function and reported transmission characteristics of an improved device we fabricated. As an experimental result, transmission coefficient of the fabricated device was about -2 dB in differential mode and -20 dB below in common mode at the frequency range from 3.8 GHz to 4.0 GHz. Finally, we described our vision of a D-CRLH differential transmission line common mode filter.

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A commercially available open-ended coaxial probe has often been used to measure dielectric properties in combination with a network-analyzer, while it can be applied to semi-infinite homogeneous materials. For thickness and size of the materials to be measured, however, their influences have not well been examined. In this study, using such an open-ended coaxial probe, we measured complex relative permittivity of pure water in the frequency range from 200MHz to 6GHz with respect to its measurement amount, and investigated the variation in comparison with the calculated values from an empirical formula for water permittivity. As a result, we found that the amount of water in a beaker with a diameter of over 35mm and a depth of 50mm provides the measurement variation within ±0.3% and -5.5% for real and imaginary parts of complex relative permittivity, respectively. It was also found that a water amount of 1.9ml in a beaker with a diameter of 35mm and a depth of over 2mm gives the variation within ±0.5% for real part and ±7% for imaginary part.

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Particle swarm optimization (PSO) is a powerful tool for designing antennas, solving inverse scattering problems, and so on. The algorithm of PSO is controlled with several parameters. Unless the parameters are selected appropriately, the search efficiency of PSO drops significantly. There are, however, no clear rules for the selection, and users have considerable difficulty to use PSO efficiently. This paper proposes a guideline and a new technique “particle refresh” for the selection to make the algorithm easy-to-use and keeping high searching-performance. The hybridization between PSO and conjugate gradient method is also discussed to utilize their complementary advantages in global exploration and local exploitation, where “attraction basin recognition” algorithm is proposed to recognizing the attraction basin area of local minima and help the algorithm to escape from local minima certainly and efficiently.

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In heavy oil-burning thermal power plants, NH₃ injection is frequently used to neutralize SO_x in flue gas. In order to ascertain the neutralization effect the concentration of NH₃ must be measured in the presence of high concentration of SO₂. Ultraviolet absorption spectroscopy in the 200-225 nm wavelength region is the most sensitive method to measure SO₂ and NH₃. However, as the absorption bands of SO₂ and NH₃ overlap, accurate determination of the SO₂ absorption is needed to detect the absorption due to trace NH₃. The nonlinear dependence of the absorption coefficient on the concentration, which appeared for absorption coefficients of α>0.05 cm^-1, is taken into account using a third order polynomial approximation in order to accurately determine the SO₂ absorption. An analysis procedure based on this approximation was developed. Results showed that NH₃ concentrations of about 4 ppm can be detected in the presence of SO₂ concentrations of about 1000 ppm.

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Experiments for observations and stabilization of discharge paths in several electrode systems are carried out aiming at precise measurement of the secondary ionization coefficient γ of MgO film electrode. The discharge chamber is filled with Ar gas. The waveforms of the applied voltage between the electrodes and the discharge current are measured with visual observation of the discharge light. Two MgO coated electrodes are placed so that they are facing each other. For these MgO electrodes, the discharge paths take a detour, not the shortest distance. Smaller prebreakdown current pulses are observed before the breakdown. After breakdown, discontinuous discharge current is observed. Therefore, it is prepared a glass tube surrounding the discharge area. As the result, the discharge paths take a straight perpendicular for the electrode surface, and the discharge is stabilized.

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Density and temporal behavior of N₂(A³Σ⁺_u) metastable, N atom, and NO molecule are measured in pulsed positive corona discharge using time-resolved laser-induced fluorescence (LIF) under atmospheric pressure. In N₂ discharge, the N₂(A³Σ⁺_u) density is independent of discharge voltage V, while the number of N₂(A³Σ⁺_u) molecules produced by the discharge increases with V because the thickness of the streamer increases with V. The absolute densities of N₂(A³Σ⁺_u) and N are measured using the decay rate of their densities after discharge by recombination reaction. In N₂/O₂(2%) discharge, the N density decreases after discharge, while the NO density is approximately constant after discharge because NO production reaction N + O₂ → NO + O and its decomposition reaction N + NO → N₂ + O are equilibrated. In N₂/NO(250 ppm) discharge, it is shown that NO in the streamer is rapidly removed by N atoms within 3μs after discharge, then NO outside the streamer is slowly removed by diffused N atoms.

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Cross-linked polyethylene (XLPE) sheets were thermally deteriorated in atmospheric air at 180°C for at most 100 hours, and microscopic structural changes due to oxidation such as material density, crystallinity, gel fraction and free volumes were evaluated by the Archimedes' technique, the X-ray diffraction method, the gel fraction measurement and the positron annihilation technique, respectively. As a result, it was found that the crystallinity and free volumes decreased after about 40 hours of heating on the upper surface of XLPE sheets where air supply was sufficient during heating and oxidation degree was high. However, on the lower surface that contacted with a metal plate during heating and was less oxidized, changes of crystallinity and free volumes were small after 40 hours of heating. When the crystallinity and free volumes decreased, the material density increased. It was also found that the gel fraction increased at 100 hours of heating. The observation results of cross-sections of XLPE sheets by the transmission electron microscope showed that lamella crystals disappeared after 40 hours of heating especially near the upper surface of XLPE sheets and agree with the change of the crystallinity. Then, the relationships between the material density, the crystallinity and free volumes in the cases of crystalline polymers such as polyethylene without deterioration and XLPE thermally deteriorated at 180°C were discussed.

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Less deterioration in magnetic properties of electrical steel sheets in the process of stamping out iron-core are necessary in order to maintain its performance. First, the influence of plastic strain and stress on magnetic properties was studied by test pieces, in which plastic strain was added uniformly and residual stress was not induced. Because the influence of plastic strain was expressed by equivalent plastic strain, at each equivalent plastic strain state the influence of load stress was investigated. Secondly, elastic limit was determined about 60% of macroscopic yield point (MYP), and it was found to agree with stress limit inducing irreversible deterioration in magnetic properties. Therefore simulation models, where beyond elastic limit plastic deformation begins and magnetic properties are deteriorated steeply, are proposed. Besides considered points in the deformation analysis are strain-rate sensitivity of flow stress, anisotropy under deformation, and influence of stress triaxiality on fracture. Finally, proposed models have been shown to be valid, because magnetic properties of 5mm width rectangular sheets stamped out from non-oriented electrical steel sheet (35A250 JIS grade) can be estimated with good accuracy. It is concluded that the elastic limit must be taken into account in both stamping process simulation and magnetic field calculation.

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This paper presents a new method to evaluate magnetostriction of a silicon steel sheet as an eigen value of 2-dimensional strain tensor. Conventional way to measure the property was to measure the strain only by the direction of magnetic flux density vector, although the directions of flux density and strain are not the same. This paper presents a method to evaluate the strain of all-around-horizontal direction using 2-dimensional strain tensor, its eigenvalue and eigenvector, and a method to measure the strain with 3-axis strain gage to calculate strain tensor. Measured results indicate that NO sheet expands by the same direction as magnetic flux density vector, although GO sheet expands to the transverse direction with no relation to the direction of magnetic flux density vector. Then an angle difference between the magnetic flux density vector and the direction of maximum magnetostriction is observed in GO material.

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Recently, some professional whistlers have set up music schools to teach musical whistling. However, so far, there is no licensed examination for musical whistling. In this paper, we propose an examination system for evaluating musical whistling. The system conducts an examination in musical whistling on a personal computer (PC). It can be used to award four grades, from the second to the fifth. These grades are designed according to the standards adopted by the school for musical whistling established by the Japanese professional whistler Moku-San. It is expected that the group examination of this examination is held in the examination center where other general certification examinations are held. Thus, the influence of the whistle sound on the PC microphone normally used should be considered. For this purpose, we examined the feasibility of using a bone-conductive microphone for a musical whistling certificate examination system. This paper shows that the proposed system in which bone-transmitted sounds are considered gives good performance under a noisy environment, as demonstrated in a group examination of musical whistling using bone-transmitted sounds. The timing of a candidates whistling tends to not match because the applause sound output from the PC was inaudible for a person older than 60 years.

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The manufacturing technology of the crystal resonators is expanding from HF band to VHF, UHF band. According to this trend, measurement methods to evaluate intrinsic nature of crystal resonators are required. In this paper, we examine about a circuit using the micro-strip line as reference plane, and discuss a precise expression to characterize the nature of the circuit.

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