The charge neutralized at a small gap discharge has been evaluated from measured electromagnetic fields by two methods. The small gap discharges simulate ESD events. The evaluated charge decreases rapidly as a step shape immediately in a moment of the discharge. The accumulated static charge and the risetime of the neutralization step increase with the gap length. When the gap length is 0.1mm, risetime and the initial static charge are about 0.3ns and 5.6nC, respectively.

The wave forms of electric and magnetic fields radiated by short gap discharges are measured to analyze electrostatic discharge (ESD) events in the near-field zone with the monopole antennas, the loop antenna and the 5.5GHz bandwidth waveform digitizer. The antenna outputs are corrected by the measured characteristics of the antennas. The relations between the measured electric field and the discharge currents are discussed.

The attenuation effect of the walls of a building on the electromagnetic (EM) field generated by an indoor power line communication (PLC) system is numerically investigated using the finite integration (FI) method. In particular, we focus on the frequency range 2-6 MHz, for which the attenuation effect has not yet been sufficiently analyzed. We model a single, finite-sized wall instead of an entire house, to focus on the dependence of the EM field on the wall structure and also reduce the computational resources required. The EM field strength is evaluated at many points on a view plane 10 m from the wall model, and the results are statistically processed to determine the attenuation effect of the wall. We show that the leakage of an EM field at 2-6 MHz is suppressed by about 30 dB by a reinforced concrete wall. We also show that the main contributor to the attenuation effect is the rebar in the wall. We then investigate the relation between the attenuation effect of a single-wall model and that of a house model. The results show that the attenuation effect of a house model is almost the same as that of a 15-m-wall model. We conclude that the use of a single-wall model instead of a house model is effective in determining the attenuation of the EM leakage. This simple structure reduces analytic space, time, and memory in the evaluation of the dependence on the wall structure of the EM leakage from indoor PLC systems.

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.

This paper describes the measurement techniques of emissions from UWB devices discussed in ITU-R task group (TG) 1/8 to study the compatibility between ultra-wideband (UWB) devices and radiocommunication services. This paper also provides the background idea behind the measurement methods, as the final output of the discussion, i.e. ITU-R Recommendation, will not contain any citations to the references, nor any "educational" description of the theoretical background.

The antenna factor measurement of the dipole antennas for electromagnetic interference (EMI) measurements is studied theoretically and experimentally. The 3-antenna method is applied to near-field. Near-field transmission characteristics between the transmitting and receiving dipole antennas is obtained by using the electromotive force (EMF) method, where sinusoidal current distributions are assumed. It is shown that the antenna factors can be measured from transmission values between two antennas and near-field correction factors at any height of each antenna.