This paper is discribed the Immunity evaluation system to analyze a malfunction distribution of PCBs by a local electro static discharge. A malfunction distribution is displayed on a picture of PCBs by 6 phased color and a voltage and malfunction discrimination code. It can detect a malfunction place being efficient by changing an electric discharge range. Incase of an experimental PCBs, reset patterns of CPU were detected as a place to be able easily to do a malfunction.

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Transient electromagnetic fields caused by the electrostatic discharge (ESD) between charged metals can be affected by the presence of the metal itself, whereas the effect has not been examined. This paper analyzes the occurrence elctromagnetic fields due to the spark between spherical metals, using the finite-difference time-domain (FDTD) method. The numerical computation reveals that the presence of the metals increase the ESD field level according to the the metal dimension. In order to confirm the above finding, we have also calculated the occurrence field level from our previously proposed ESD source model, which consists of numberiess image dipoles that give the equipotential condition on the spherical metal surface.

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In an image reconstruction of SAR (Synthetic Aperture Radar) using the range-azimuth compression algorithm, the image intensities of targets at a same distance from the radar are emphasized, resulting in masking the other images. In this report, an image reconstruction method with spatial-frequency domain processing, in which the above impropriety can be avoided, is proposed. Computer simulations and experiments are made to show the usefulness of the new method.

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For evaluating the 2-dimensional positions of electromagnetic reflection points near to a radar, two methods are proposed. One method is that the MUSIC algorithm is used for the range compression and the data are line-integrated for the azimuth compression. This method is applicable for the coherent (passive) reflection using the spatial smoothing techniques. Another method is developed for the incoherent (active) reflection. A mode vector for near-positions is defined for the 2-dimensional evaluation by MUSIC algorithm only. The results of Computer simulations and experiments with an intensity-modulated laser radar are shown. The latter method for the incoherent reflection gives quality images with high resolution in return for the complicated structure of the active targets.

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Fundamental study has been conducted on the biological effects of ELF (Extremely Low Frequency) electric field. A perception threshold was measured with human subjects and the results were analyzed. The perception threshold was lower in an AC field exposure than in a DC field exposure. One of the causes of individual difference in the threshold was found to be the difference in the physical conditions of body hair. The psychological conditions of a subject were forced to be changed by giving different amount of information on the field exposure. The threshold was also dependent on the psychological conditions. However, these variances in the threshold were far smaller than the variance caused by the change in relative humidity.

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Abstract Influence of induced current on the goldfish behavior and body-color by a time varying magnetic field was investigated in this paper. The exposure of the 70Hz, 26mT magnetic field suppressed the behavior of goldfish. This exposure also discolored the goldfish body. The electric current induced to the body by the time varying magnetic field was calculated using the spheroid model of goldfish. When this current was directly passed with electrodes, the body-color of goldfish changed. As the swimming behavior of goldfish at the 150mT static magnetic field had become fast in the previous study, the mechanism was again argued in this paper.

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We examined an equivalent circuit of the line noise filters by using attenuation characteristics. As a result, an equivalent circuit equal to an almost actual filter was obtained by obtaining constants of the filter parts which considered the influence of line impedance and the stray element when mounting. Moreover we examined the relationship between static characteristics and dynamic characteristics for Attenuation characteristics, and confirmed that these characteristics shows similar form. In addition, it was clarified to be able to examine the optimization of the line noise filters only with the requested equivalent circuit.

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Abstract This paper describes a measurement of multipath characteristics with microwave link in 7GHz band, a new window function used in Fourier analysis and relationship between multipaths and quality grading of impaired television pictures. The measurement hasn't been possible because its transmission line is not linear. But we measured the characteristics using its group delay characteristics only. As a result, there exist plural multipaths on each transmission line. And some of them have long delay times for example 1470ns long. Also we have developed a new window function that gives a high resolution of this measurement, and resolve two multipaths with 60ns difference in time. Further more, we study the DU ratio that is required for transmitting pictures without impairment.

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We have developed a terrestrial digital sound broadcasting system using OFDM (Orthogonal Frequency Division Multiplexing) which has a strong durability against fading and multipath. In this paper, we describes, mainly, the fundamental performance of this system obtained indoors.

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Radio absorptive properties in (γ-Fe_2O_3/T_iO_2)=(90/10) weight ratio composite materials for VHF, UHF and GHz band have been investigated. Permittivities and permeabilities Of (γ-Fe_2O_3/T_iO_2) composite materials are discussed for optimum trial design for radio absorptive sample that are indispensable for protection of electric equipment from external noise. The absorption properties of the sample with 0.2 cm in thickness demonstrates 681 MHz in bandwidth centered at 4.45 GHz as an experimental example.

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Radio absorptive materials and shielding materials in microwave frequencies, which can be used for the hazardous EM radiation circumstances, have been studied. The measuring frequencies from 40 MHz to 20 GHz, the materials dispersed graphitized carbon, acetylene carbon and carbon fiber in silicone rubber are discussed. To compare with the ideal properties for the single layer radio absorptive materials, it is found that good absorptive characteristics can be obtained as long as narrow frequency band. Also, to apply the developed material shown here, good shielding materials can be realized. The data of the shielding material is also shown in this report.

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This paper discribes a method on simply changing the matching frequency characteristics of an EM-wave absorber and improving the matching characteristics using a Open-hole ferrite material. As the result of experimental and theoretical investigation, the ferrite with Cross-shaped holes shows a good characteristic that it is able to change the matching frequency characteristics broadly. As for the theoretical analysis of matching characteristics, Spatial Network Method have been introduced. It is clarified that the matching frequency is changed from 2[GHz] to 4[GHz] using the ferritematerial with Cross-shaped holes.

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Recently, mobile communication systems are often used inside the buildings. For the effective use of these systems, it is important to know the radio wave propagation characteristics inside buildings. A major prerequisite in the analysis of this is electromagnetic characteristics of the slab component of the walls and decks. As reinforced concrete slab (RC) slab is a highly used building slab component and has much influences on radio wave propagation, we attempt to formulate a model to determine the characteristics. We analyze the reflection and transmission characteristics of reinforcing bar mesh, and the dependence of complex permittivity on the frequency and the water content of concrete. Also, some shaped slabs are modeled as multiple stratification and characteristics are analyzed by numerical and experimental methods.

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The results of the studies of an inverse scattering problem to estimate the underground objects is presented. A reflected wave, from buried objects in radiating random media such as the underground, contains many clutters and these make the detection of buried objects difficult. To reduce the clutter of reflected wave from the underground, we have proposed a signal processing technique using wavelet transform. We analyzed the reflected wave with emphasis on the wave from the buried objects. In addition, we have analyzed the effect of rough surface on subsurface radars.

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