The radio-frequency protection guideline of Japan recommend the limits of contact current for contact hazard due to an ungrounded metallic object under an electromagnetic field in the frequency range from 10 kHz to 15 MHz. To arrange the standard measurement methods of contact current in Japan, the contact body impedance for the Japanese in the frequency range from 75 kHz to 15 MHz is obtained, and the simplified equivalent circuit is determined using nonlinear least squares method. In addition, the human body impedance is obtained from numerical simulation using the impedance method and voxel human model, and compared it with measured one.

To clarify the correspondence between Shielding Effectiveness (SE) of shielding materials and their physical property, we propose an equivalent circuit for a shielding effectiveness test apparatus using a dual TEM cell, and show its validity. By considering the structure of dual TEM cell that consists of a pair of cells coupled via an aperture in their common wall, we defined the capacitance C and mutual inductance M, that respectively express the electric coupling and magnetic coupling between two center conductors. By the measurement of unloaded S-parameter, we determined the values of C and M for a dual TEM cell in hand. Next, the shielding material was approximated by the apparent sheet resistivity Rs, and was used in the equivalent circuit of loaded aperture. As a result, the coupling level calculated from the equivalent circuit agreed well with the measured data in frequencies below 300 MHz.

In using a reverberation chamber for radiated immunity testing, it is important to determine the number of discrete steps through which the stirrer rotates and the number of probe locations for a given test volume in the chamber. This is because they affect the uniformity and calibration of the field in the test volume. We experimentally evaluated the effect of the numbers of stirrers and their steps on the field uniformity, and the effect of the number of probe locations on field calibration.

The use of the in-phase synthetic method is proposed for antenna calibration using the three-antenna method (TAM) in order to make the TAM applicable even in a semi-anechoic chamber (SAC) or on an open-area test site. Suitable antenna arrangements are theoretically investigated for this improved calibration method. Experimental analyses demonstrate that the in-phase synthetic method can remarkably reduce unwanted effects of the ground-reflected wave. Therefore, even on a metal ground plane, the proposed TAM with the in-phase synthetic method can yield an accurate actual gain of a double ridged guide antenna at frequencies from 4 GHz to 14 GHz with differences of +0.16/-0.37 dB from the results of the conventional TAM performed in an fully anechoic room (FAR).

The measured values of electromagnetic disturbances should strongly correlate with degradation in the communication quality of digital wireless communication systems. The Amplitude Probability Distribution (APD) of a disturbance represents statistical information as applicable measurement readings that meet the above requirement. In this paper, correlations between APD measurements of disturbances and the bit error rate (BER) as a quality degradation index for victim systems are quantitatively investigated. Disturbance regulation by APD measurements is discussed from the viewpoint of protecting systems from disturbances. This investigation specifically considers the situation in which a repetition pulse disturbance impacts PHS and W-CDMA systems assumed as victims. The results confirm high correlations between the APD and BER not only experimentally but also theoretically under some conditions. A disturbance regulation criterion based on APD measurements is thus proposed for compliance testing of electronic appliances with the potential to act as disturbance noise sources.

The data dispersion of the measurement of electromagnetic disturbance above 1 GHz is mainly affected by site imperfections (expressed by the site voltage standing wave ratio (SVSWR)). To confirm the relationship between site imperfections and the measured field strength, we measured the SVSWR and the field strength radiated from the equipment under test (EUT) by changing the area covered by the RF absorber on the metal ground plane. From the results, we found that the data dispersion of measured field strength can be estimated from the measured SVSWR, and therefore, we can determine the measurement uncertainty of the measured field strength at the test site.

To evaluate whether electromagnetic disturbances that leak from PC displays contain information or not, we need to reconstruct the information from the measured disturbance. This requires a special receiver, and not all test houses have a special receiver. In this paper, we propose performing the evaluation with the spectrum analyzers commonly used for EMI measurement. First, we select a spectrum that containing the frequency component of the vertical sync signal using a spectrum analyzer (SA1). Then, we measure the video output of SA1 using another spectrum analyzer (SA2) and evaluate the disturbance from the frequency component of the horizontal sync signal.

The electromagnetic disturbance that leaks from ICT (information and communications technology) equipment might contain important information. Our measurements show that the information hidden inside of the electromagnetic disturbance can be monitored. First, we measured the level of the electromagnetic disturbance that leaks from laser printers and collected the waveform in the time domain. Then, we reconstructed the printed image from the data. As a result of our measurements, we found that at points 200 cm away or beyond it is difficult to reconstruct the printed image, and therefore the threat to electromagnetic security is not significant.

Noise waveform analyzer was developed to measure the statistical distributions such as amplitude probability distributions of noise envelope. Using this system installed in a van, some statistical distributions of automotive radio noise in lower frequency microwave bands (1-3 GHz), received while driving on main streets and expressways in Tokyo, were measured to provide fundamental data for designing mobile communication systems in this frequency band. Variation of the impulse height, received in typical driving conditions, can be expressed by a log-normal distribution and impulse emission seems to be Poisson-distributed in time for time history records as long as 40 minutes.

Site attenuation (CSA) is investigated theoretically and experimentally for soil ground test sites as well as for metal ground test sites. In this study, half-wave tuned dipole antennas are used in the arrangements specified in ANSI standard. The CSA is evaluated numerically by introducing effective reflection coefficients, which yield an excellent agreement between theoretical and experimental results. It is found that, for horizontal polarization, differences in the CSA values between soil ground test sites and metal ground test sites decrease with increase in antenna separation distance. The deviation may reach about 4 dB for a separation of 3 m. On the contrary, in the case of vertical polarization, the CSA values of soil ground test sites deviate more than 6 dB from those of metal ground test sites at longer separation distances, such as 10 m or 30 m. In addition, theoretical investigations were made on effects of dimensions and terminations of the dipole antennas used in site attenuation measurements.

A new method to measure the effective radiated power (ERP) of transmitters is proposed. The effects of nearby reflecting objects, which introduce measurement error, are canceled by the in-phase synthetic method, and therefore, this proposed measurement method is practicable even in a small test site. Theoretical formula is derived and error is evaluated using a simulation technique. Experimental results prove the validity of this method. Its application to anrtenna gain measurement, as well as the ERP measurement of communications equipment, is also presented.

TEM-mode electric field uniformity on the transverse plane that was perpendicular to a floor conductor of a GTEM (gigahertz transverse electromagnetic) cell, and the usable test volume in the cell, were evaluated both theoretically and experimentally at frequencies of up to 1 GHz. Electric fields in the GTEM cell were calculated by using the FD-TD (finite-difference time-domain) method. The fields were measured by using an optical E-field (electric field) sensor in order to confirm the calculation result. CISPR/A (CISPR: Comite International Special des Perturbations Radioelectriques) and IEC (International Electrotechnical Commission) SC77B proposed in their committee draft that the usable test volume was 0.6W 0.33h, where W and h were a width of the septum (inner conductor of the cell) and a distance between the septum and the floor conductor of the cell, respectively. We found that the usable test volume, i. e. the maximum width and height of an EUT, by the committee draft are reasonable and applicable for a GTEM cell.

Broadband antennas such as biconical antennas and log-periodic dipole antennas are generally used in automatic EMC measurements. However, these broadband antennas have not been used for accurate measurement because accurate specifications for them are lacking. Therefore, more accurate analysis is urgently required by the CISPR (International Special Committee on Radio Interference), to establish the specifications for broadband antennas for EMC measurements. In this paper, the AF of biconical antennas is calculated by using Moment Methods. The frequency characteristics and antenna height dependency of AF are presented. AF is also measured and compared to the data obtained by the calculations. Good agreement between the calculations and measurements is achieved, indicating the usefulness of our computation method. In addition, the effect of antenna separation distance and transmitting antenna height on AF is investigated. The calculated AF deviation from the reference value is nearly 0dB except for certain antenna arrangements. In these antenna arrangements, the field becomes null at the receiving antenna and widely varies in magnitude and phase around the null points. Therefore, the antenna is immersed in a non-uniform field, while the AF is defined on the assumption of a uniform field. Consequently, the erroneous AF will be derived from measurements around these null points and it will be greatly different from that obtained at other antenna heights. Thus, it is better to avoid these conditions during actual measurements. The effect of the ground plane on AF is also evaluated. AF is shown to be seriously affected by the ground plane especially at frequencies around 90MHz. It should be noted that AF deviation has crests corresponding to the null field at 300MHz. The obtained data will be useful in establishing specifications of biconical antennas for EMC measurements.

A new hybrid formulation has been derived for analyzing biological electromagnetic compatibility (Bio-EMC) problems by combining the frequency-domain Method of Moments (MoM) and the Finite-Difference Time-Domain (FDTD) method. This hybrid form is different from, and more direct than, the method previously proposed by Mangoud et al. Some numerical examples are given for the human head exposure field due to a half wavelength dipole and a one-wavelength loop antenna. Our iterative method is found to have fast convergence. In addition, our method works well for cases when the radiation antenna wires are not aligned with the FDTD lattice.