Kimitoshi Murano

A new immunity test method

A new measurement system and a mapping technique for immunity or susceptibility testing are discussed. The most unique point of the system is that the electromagnetic (EM) fields are of slowly rotating polarization controlled electronically. In this paper, methods for generating slowly rotating fields are discussed. The direction of field polarization can be varied continuously and in a short time. By combining the method with a turntable, for example, the immunity-or susceptibility-characteristic maps can be obtained easily. This visualization technique is useful to detect the immunity or susceptibility attributes at a glance and thus may make the development of products with high immunity easy.

Susceptibility characterization of a cavity with an aperture by using slowly rotating EM fields: FDTD analysis and measurements

This paper describes the evaluation of the susceptibility of a cavity with an aperture using the finite-difference time-domain (FDTD) method and experimentally. To reduce the computing time, the FDTD method is used for the radiation from the cavity and the susceptibility is obtained by using the reciprocity theorem. The cavity used here is modeled after a full-tower desktop enclosure with a 3.5-in bay. The susceptibility characteristics are evaluated by measuring outputs of a monopole antenna and transmission lines installed in the cavity. The susceptibility characteristics, using a three-dimensional (3-D) map, are studied from the computed and the measured results by applying slowly rotating electromagnetic fields to the cavity on a turntable. Measured and modeled results are in good agreement, indicating the merits of the proposed approach for susceptibility/immunity evaluation. Moreover, some discussions are made to check the susceptibility mechanism.

Novel Right-Handed Metamaterial Based on the Concept of “Autonomous Control System of Living Cells” and Its Absorber Applications

A novel right-handed metamaterial similar to an “autonomous control system of a living cell” and capable of responding to electromagnetic waves is proposed with its fundamental configurations. Using microwave absorbers as an example, the possibility of equivalently controlling their material constants are investigated both theoretically and empirically. These absorbers are composed of unit cells based on the concept of an autonomous controllable metamaterial (ACMM). The theoretical approaches used to obtain ACMM-based absorber design data are revealed. In order to improve the absorber matching characteristics, the principle of obtaining the broadband matching characteristics with an absorption band of 1.3 GHz at 4.25 GHz is clarified. In addition, the methods for improving the matching degradation of the oblique incidence of a TM wave are investigated. For the TM wave oblique incidence, a new ACMM-based absorber configuration comprising unit cells with inductive fins is proposed. At an incident angle of 45°, a matching characteristic of -30 dB is achieved in the case of the TM wave. These ACMMs are controlled by using only two bias feeder wirings for PIN diodes.

Mode-Port-Network Approach to Analyze Power-Line EMC Problems for PLC

In Japan, a power-line communication (PLC) is in use as an indoor system in the frequency band of 2 MHz to 30 MHz. However, the radiated emission in this frequency band, which is caused by the common-mode current generated in the power-line systems, is a serious matter. To analyze the high-frequency behavior of the line system, a two-port-network model using differential- and common-mode ports is proposed here. As an example, the network-function expression is effectively used to analyze characteristics such as longitudinal conversion loss (LCL), induced common-mode currents in a power line having a load circuit, and an impedance stabilization network 1 (ISN1) attached to a PLC modem.

Common-mode inductance and radiation of edge placed differential traces on printed circuited board

With respect to the single-ended trace (track), differential signaling is most advantageous to signal integrity and common-mode radiation level reduction. However, to guarantee the required signal transmission, the two tracks in the differential pair should be perfectly balanced. Edged placement of a differential pair on the PCB causes balance disruption and creates common-mode (CM) currents resulting in an increased electromagnetic interference level. We quantify the CM inductance and radiation from differential tracks with edge placement. The common-mode inductance of an edged-placed differential pair on a PCB is derived. Then the characteristics of the common-mode inductance of a differential pair are studied for different geometries. Finally, the total radiation powers for several geometries due to the edge placement of the differential pair are measured.

Circuit Model for Two Parallel Microstrip Lines on Slotted Ground Plane

A transmission-characteristic analysis of two parallel microstrip lines on PCB with a slotted ground plane is studied. When two trace lines are very closed, crosstalk occurs between them. In addition to it, magnetic-field coupling between the traces and the slot line also exists. In this paper, a circuit model for transmission characteristics of such line system is proposed. The calculated results are compared with the experimental results to veryfy the proposed model.

Analysis of Crosstalk between Single-ended and Differential Lines

The crosstalk between single-ended and differential lines is investigated in this paper. First, the telegraphers equations for multiconductor line are applied. Then the differential pair is terminated respectively with T and Π termination networks, and the crosstalk from the single-ended trace to the differential pair is evaluated at the grounded resistors in the T or Π termination networks. The analysis of the crosstalk is obtained by incorporating the termination network with the solution of the telegraphers equations that are solved by using a mode decomposition technique. DOI: 10.2529/PIERS060904050207

An immunity/susceptibility test method using electromagnetic wave of rotating polarization

An immunity/susceptibility test method using electromagnetic waves of rotating polarization is described and test results are discussed. Low-rate rotation of the field polarization is controlled electrically and continuously in a two-dimensional plane, so that radiated immunity/susceptibility characteristics that are three-dimensionally depicted can be obtained by using a turntable together with this method. This paper explains how the rotating fields are generated, and discusses experimentally measured characteristics of several test examples. The results show the effectiveness of the proposed method for quickly visualizing the weak/strong immunity/susceptibility directions, demonstrating its usefulness for application in the trial phase of a product development.

Local Inductive Heating Method Using Novel High-Temperature Implant for Thermal Treatment of Luminal Organs

The authors have previously proposed both a regional heating system, which introduced auxiliary electrodes, and a local inductive heating system, which introduced high-temperature-rise implants. In this paper, we present two novel types of high-temperaturerise implants aiming at luminal organ treatments, namely, a coaxial needle and a stent. Since hot-spot generation may degrade the accuracy of temperature measurements when developing these inductive heating implants, a simple method using a high-conductivity eddy-current absorber such as an aluminum foil is proposed. This is suggested based on theoretical investigations using the 3-D finite-element method and experiments. The heating tests of the novel folding-type implants suggested by medical doctors were conducted at a frequency of 4.0 MHz and an output power of 500 W using the proposed EC A. It was found that in the case of the coaxial-needle-type implant, a high temperature rise of more than 60 omicronC can be achieved.

Design of a Four-Septum TEM Cell for Immunity/Susceptibility Test

The four-septum transverse electromagnetic (TEM) cell is like the traditional TEM cell but has four plate-like septa in the internal space. A slowly rotating field can be easily generated in the four-septum TEM cell, thus radiated immunity/susceptibility characteristics of an EUT under arbitrary specific polarizations can be measured without rearranging the test setup. A design approach for the four-septum TEM cell is discussed in this paper. The characteristics of the cell are analyzed based on the telegraphers equation and decomposition of the transmission mode into four independent modes. Then a design approach is given based on the analytical results. A prototype of the four-septum TEM cell based on the design is constructed and the characteristics of the prototype cell are experimentally evaluated. The validity and effectiveness of the design approach are confirmed.