Unwanted electromagnetic emission occurs due to the common-mode current on the cables entering a PC's metal enclosure and can be treated as wire antennas passing through the apertures of the enclosure. To reduce the emission, a stack of metal rings is suggested to be placed around the cable and external to the aperture, adopting the concept of a Coaxial Band-Stop Filter, for the first time. The influence of this novel structure on the common-mode current is examined in the FDTD-method frame work.

It has been demonstrated that a common-mode (CM) current can dominate the EMI processes up to 1 GHz, despite the fact that a CM current is smaller than a differential-mode (DM) current. However, this description is insufficient to describe behavior above 1 GHz. In this paper, the correspondence of CM and DM components for total electromagnetic (EM) radiation from a printed circuit board (PCB) with surface microstrip line, which is commonly used in microwave integrated circuits, at gigahertz frequency is studied experimentally and with finite-difference time-domain (FDTD) modeling. In order to characterize the EM radiation, the frequency response of the CM current, the electric field near the PCB, and the electric far field are investigated. First, the frequency response of the CM current, near and far-fields for the PCB with an attached feed cable are compared up to 5 GHz. Although the CM current decreases above a few gigahertz, near and far electric fields increase as the frequency becomes higher. Second, in order to distinguish between CM and DM radiation at high frequency, the frequency response and the angle pattern of the far-field from a PCB without the feed cable are discussed. The results show that radiation up to 1 GHz is related to the CM component. However, depending on polarization and PCB geometry, radiation may be dominated by the DM rather than the CM component. The results indicate that the DM component may be more significant relative to the CM component, and the increase in EM radiation can not be predicted from only the frequency response of CM current. Therefore, identifying the dominant component is essential for suppressing the EM radiation. This study is a basic consideration to realize a technique which is effective on the suppression of the EM radiation from the PCB with an attached feed cable.

This paper presents a systematic methodology for the system-level assessment of signal integrity and electromagnetic compatibility effects in high-speed communication and information systems. The proposed modeling strategy is illustrated via a case study consisting of a critical coupled net of a complex system. Three main methodologies are employed for the construction of accurate and efficient macromodels for each of the sub-structures typically found along the signal propagation paths, i.e. drivers/receivers, transmission-line interconnects, and interconnects with a complex 3D geometry such as vias and connectors. The resulting macromodels are cast in a common form, enabling the use of either SPICE-like circuit solvers or VHDL-AMS equation-based solvers for system-level EMC predictions.

A visualization method of coherent source locations based on the Sampled Pattern Matching (SPM) method is described. Modified SPM method is proposed to improve the S/N, in which the measurement of the electric field distribution is repeated in appropriate time duration and eigenvalue decomposition of the covariance matrix is introduced. A combination of the modified SPM method with the Weighted Subspace Fitting (WSF) method is also proposed to estimate accurate source locations. A calibration technique by using a reference antenna to compensate the complex pattern of the receiving antenna is proposed. Experimental investigation to estimate source location for one dipole antenna and two dipole antennas is also made to demonstrate the validity of the proposed method.

General exercise approaches are not convenient for some people in undertaking appropriate exercise due to the limited variety of present programs at existing exercise machines. Moreover, continuous support by one sports doctor is only available for a limited number of users. In this paper, therefore, we propose an Internet-based technical framework, which is designed on multi-tiered client/server architecture, for integrating and easily upgrading exercise programs. By applying the technical framework, a cycle ergometer health promotion system was developed for providing personally fitted. We also presented some facilities to assist sports doctors in quickly designing and remotely improving individual exercise protocols against cycle ergometer exercise based on a history database. Then we evaluated the Internet-based cycle ergometer system during two months of feasibility experiments for six elderly persons in terms of usability. As a result, the Internet-based cycle ergometer system was effective for continuously supporting the personal fitting procedure.

We study radiated RF (radio-frequency) electromagnetic field immunity test system for wireless LAN system by using opened PW (Parallel Wired) cell, in which metal cover is removed. Leakage electric field at distance of 160 cm from the opened PW cell decreases until 30 dB, and then does not affect to operation of the AP (Access Point) composed of the wireless LAN system that communicates EUT (Equipment Under Test) installed in the PW cell. NSA (Normalized Site Attenuation) between EUT and AP changes only several dB by inserting the PW cell, and then it can be concluded that the effect of PW cell for radio wave property of wireless communication system is negligible small. In addition, we try to measure dependencies of impressing level of disturbance wave on a throughput of wireless LAN systems IEEE802.11b and IEEE802.11g. As a result, it is confirmed that the radiated RF electromagnetic field immunity test system for wireless LAN system can be composed by using the opened PW cell without affecting from impressing disturbance wave.

Electromagnetic (EM) radiation from a feed cable attached to a printed circuit board (PCB), which is commonly encountered electromagnetic interference (EMI) problem at high-speed electronic PCB designs, is investigated by experimental and finite-difference time-domain (FDTD) modeling. In this paper, we propose and demonstrate a guard-band structure as a method for suppressing the EM radiation from a PCB with a feed cable. A signal trace is located between two ground traces (guard-band: GB). Four different cross-sectional PCB structures, which are commonly used in microwave integrated circuits as typical structures, are used to compare the guard-band structure. Frequency response of common-mode (CM) current, electric field near a PCB, and far electric field (radiated emission) are investigated as characteristics of the EMI. Results show that the shield structure is effective in suppressing the CM current at lower frequency. However, structures in which a conductive plate exists near the signal trace yield resonances with high level peak on CM current, near and far-field. On the other hand, the guard-band structure is more effective than other structures in suppressing the EM radiation in the considered frequency range. Therefore the guard-band will be effective for high-density PCB packaging with high-speed traces.

It is well known that both shape and motion can be factorized directly from the measurement matrix constructed from feature points trajectories under orthographic camera model. In practical applications, the measurement matrix might be contaminated by noises and contains outliers. A direct SVD (Singular Value Decomposition) to the measurement matrix with outliers would yield erroneous result. This paper presents a novel algorithm for computing SVD with outliers. We decompose the SVD computation as a set of alternate linear regression subproblems. The linear regression subproblems are solved robustly by applying the RANSAC strategy. The proposed robust factorization method with outliers can improve the reconstruction result remarkably. Quantitative and qualitative experiments illustrate the good performance of the proposed method.

In this paper, dosimetry of an in vitro exposure apparatus based on a cylindrical waveguide is performed. The SAR distributions are first obtained numerically by using FDTD method. The thermal fields in the medium are then estimated by numerical calculations of the equation of heat conduction. The maximum temperature rise for 17.9 W/kg average SAR during 3000 s exposure is about 2 on the bottom of the medium where cells are located. The thermal distribution is relatively uniform near the center of the dish and the temperature in this region is around 38.7. The results of the numerical calculation are experimentally supported. The results provide the electromagnetic and thermal characteristics of the exposure apparatus, which will define the exposure conditions of the planned experiments using this apparatus.

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.

We have studied on the interference test method from IEEE802.11b to IEEE802.11g as an interference source with wide band spectrum by using the opened PW cell, and it is clear that the throughput of IEEE802.11g for only IEEE802.11b Ch.4 signal wave as the interference wave, whose frequency spectrum is almost not overlapping with IEEE802.11g, is almost not interfered by IEEE802.11b, but the throughputs for all other channels from Ch.5 to Ch.8 as the interference wave are interfered and decrease to below 2 Mbps. By comparing with conventional radiated RF electromagnetic field immunity test specified by IEC 61000-4-3, it is clear that the conventional immunity test cannot simulate the interference phenomena from IEEE802.11b to IEEE802.11g. Next, we tried to perform the interference test of the Bluetooth against the wireless LAN IEEE 802.11b as a disturbance source. As a result, it is revealed that the throughput of Bluetooth decreases according to increasing the interference wave level, and communication between EUT (slave) and the master of Bluetooth is interrupted for the interference wave corresponding to Ch.7 (244210 MHz). However, in the conventional immunity test specified by IEC 61000-4-3, the throughput of the Bluetooth does not affect for the all disturbance waves corresponding to the center frequency of bandwidth on the cannel of IEEE802.11b. Therefore, it is needed for the wireless LAN and the Bluetooth to develop new radiated immunity test method, which has the disturbance wave with wide bandwidth.

A compensation method of the array element pattern is proposed to measure EM field distribution on an observation plane located several wavelengths away from electronic devices in a short time. Numerical and experimental data of the 3 and 5 element collinear dipole array sensors are presented to demonstrate the validity of the proposed method.

Modern telecom and signal relays have been optimized to carry and switch low signals and to withstand high dielectric strength. Recent designs have extremely small physical dimensions and are comparatively cheap. Small size and low cost also make this type of relay very attractive for industrial and automotive applications. For industrial and automotive applications performance characteristics other than low and stable contact resistance values are of importance. While, for industrial applications, safety aspects and inductive load switching characteristics are of major importance, in automotive applications, high switching currents, inductive and lamp loads and high ambient temperatures are essential. Tests were carried out in order to determine the limitations of small size relays. The results obtained clearly show the unexpectedly high load range which signal relays are able to cover. Despite their small size, these relays can handle switching loads up to several hundred volts and currents up to 5 A. On top of the high switching current there is high excess current capability, and relays can work at extreme ambient temperatures between -55 and more than +105 degrees C.

A new microstrip compatible phase shifter circuit is introduced. The phase shifter uses a strip-type electromagnetic bandgap (EBG) substrate in place of the solid metal ground plane. Such EBG substrates, when made of ferroelectric materials, can produce variable phase constants useful for phase shifter applications. Test models using two different EBG substrates with dielectric constants of 9.2 and 10.2 showed 44.5 degrees of phase difference with 1.7 dB of added insertion loss at 10 GHz from a line originally 504 degrees long.

A fully integrated broadband distributed frequency tripler, periodically loaded with HBV devices, has been designed and fabricated and has demonstrated the generation of a broad range of output frequencies of up to 570 GHz. Key to the design is the principle that the entire frequency tripler circuit is produced monolithically and incorporates novel HBV devices electrically and mechanically interconnected by a thin low-loss SU-8 membrane. With the device fabrication approach used, the novel HBV devices are able to produce a higher capacitance-voltage swing ratio whilst simultaneously minimizing the device series and contact resistances to achieve the optimum conversion efficiency. The entire concept of this work was to design a cost effective fully integrated waveguide package, with the frequency tripler circuit mounted at the E-plane of a micromachined waveguide which was constructed with stepped height and width to prevent the propagation of higher order modes inside the waveguide sections. The micromachined waveguide sections exhibit high dimensional accuracy and a good surface finish which is necessary for the efficient propagation of high frequency signals. The frequency tripler circuit and the accompanying micromachined waveguide sections are mounted in a specifically designed metal test fixture to form a compact and cost-effective subcomponent with great commercial potential for broadband harmonic generation of up to terahertz frequencies. This paper presents the design methodology and techniques used to produce the frequency tripler package, together with some initial measurement results.

There have been significant advances in computational electromagnetics (CEM) in the last decade for a variety of antennas and propagation problems. Improvements in single frequency techniques including the finite element method (FEM), the fast mulitipole moment (FMM) method, and the method of moments (MoM) have led to significant simulation capabilities on basic computing platforms. Similar advances have occurred with time domain methods including finite difference time domain (FDTD) methods, time domain integral equation (TDIE) methods, and time domain finite element (TD-FEM) methods. Very complex radiating and scattering structures in the presence of complex materials have been modeled with many of these approaches. Many commercial products have been made available through the efforts of many individuals. The CEM simulators have enabled virtual EM test ranges that have led to dramatic improvements in our understanding of antennas and propagation in complex environments and to the realization of many of their important applications.

A 3-bit flash analog-to-digital converter (ADC) for electronic dispersion compensation (EDC) was developed using InP HBTs. Nyquist operation was confirmed up to 24 Gsps, which enables oversampling acquisition for 10 Gbit/s non-return-to-zero (NRZ) signals. The ADC can also be operated at up to 37 Gsps for low input frequencies. To reduce aperture jitter and achieve a wide band of over 7 GHz, an analog input signal for all pre-amplifiers and a clock signal for all latched comparators are provided as traveling waves through coplanar transmission lines. EDC was demonstrated by capturing a 10-Gbit/s pseudo-random bit stream (PRBS) with the waveform degraded by polarization-mode dispersion (PMD). By using the captured data, we confirmed that a calculation of a transversal filter mitigates PMD.

The finite difference time domain (FDTD) method has been developed in tandem with the progress of computer technology since K. S. Yee applied it to the analysis of an electromagnetic problem in 1966. The FDTD method is widely recognized as a powerful computational tool for analyzing electromagnetic problems involving complex geometries, such as antennas, microwave and optical waveguides and interaction between antennas and the human body. The commercial electromagnetic simulators based on the FDTD are also being developed very actively because users are able to trace temporal electromagnetic behaviors and to easily obtain a practical level of accuracy. However, the user must understand the principle of the method in order to use the simulator efficiently. In this paper, the basic concept and the principle of the FDTD method are reviewed for beginners, including graduate course students, rather than specialists in this discipline. Several recent topics concerning electromagnetic and antenna problems are also introduced.

The theory of the method of moments (MoM), which has been widely used as a numerical technique for analyzing the characteristics of antennas and scatterers, is described. First, the steps of MoM to solve integral equations for conducting wires and planes are presented. It is pointed out that MoM combined with Galerkin's method yields highly accurate results. The importance of ensuring the continuity condition of current on conducting bodies is emphasized and numerical examples for a conducting structure involving junctions of wire segments and planar segments are presented. Finally, MoM for dielectric scatterers including recent developments is described.

This letter presents a reduction technique of penetrated electromagnetic fields through a narrow slot in a planar conducting screen. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the two parallel wires connected on the slot. The magnitude of penetrated electromagnetic fields through a narrow slot is controlled by electric field distributions on the slot aperture. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by installing the two parallel wires on the slot.