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We proposed EM-wave absorber with periodic patch antennas. It has two feed points on a square patch. We simulated electromagnetic field of patch antennas having infinite periodic structures by using FDTD method and designed at 2.4GHz band. Then, we manufactured and measured the EM-wave absorber for 2.45GHz. As a result, both H- and V-polarized waves could be absorbed at 2.4GHz.
This paper describes a measurement method of electromagnetic shielding effectiveness in low frequency. In order to measure the magnetic shielding effectiveness, loop antennas are usually used. When a type of shielding material is sheet or cloth, it is easily put up inside a loop antenna. Therefore, we propose a method to measure a magnetic shielding effectiveness of materials whose type is sheet or...
The practical approach to implement a 1 Ω current probe with verification for measuring the IC conducted emission is proposed. The 1 Ω/150 Ω direct coupling method is reviewed and the considerations on improving the applicable bandwidth of 1 Ω method are discussed. The critical component, 1 Ω resistor which dominates the frequency response, is designed. The realized 1 Ω probe was fully certified with...
This paper reports standardization activities in CISPR and introduces newly developed limits and measurement method of conducted disturbances at the DC ports of Grid Connected Power Converters (GCPCs) applied to solar-photovoltaic power (PV) generating systems. First, background of standardization activities on the development of the limits and measurement method is described. Second, the two proposals...
In this paper, the electromagnetic compatibility issues of wireless powered electric vehicle are discussed in the view of electromagnetic field and electromagnetic interference. The magnetic field reduction for human exposure for near field is investigated and the definition of electromagnetic interference measurement is discussed.
Conductive noise from vehicle equipments which contain inverter circuits has been increased by the demand of higher switching operation of power devices in order to improve the power efficiency. On the other hand, since the vehicle equipments are required to minimize the volume, the noise filters should be built-in the housing of inverter circuits. In this case, it is necessary that the conductive...
By advance of miniaturization of electronic devices, a ground plane of a printed circuit board is tend to be small and complicated and the ground plane may have some defects, such as connectors or clearance halls of vias. In this paper, we analyzed the coupling between a microstrip line and a slot in a ground on a PCB using the MTL method to examine an effect of the signal integrity for the slot in...
At a differential transmission line bend, a differential mode propagated in a differential transmission line is converted to a common mode due to asymmetry of the transmission line. The common mode conversion leads to problems with signal integrity. We propose a method to improve electric symmetry of the transmission line bend and thus reduce the common mode conversion. The self-capacitance and inductance...
A tightly coupled asymmetrically tapered bend to suppress differential-to-common-mode conversion (caused by bend discontinuity in a pair of differential transmission lines) is proposed. A tightly coupled tapered bend has been proposed to suppress the mode conversion by decreasing the path difference in the bend. The tightly coupled bend with symmetric tapers makes the path difference shorter so that...
For differential-signaling system, the ideal balance or symmetrical topology cannot be established due to bend (turnoff point) discontinuities, and hence, an imbalance component is excited. Therefore methodology and geometrical-structure for satisfying both SI and EMI performances are indispensable. In order to provide basic considerations for the realization of methods for predicting and suppressing...
An effective method s proposed to enhance the SI and PI of a power-bus structure PBS) in a layered medium PCB by suppressing the EMI-causing resonance mode It s implemented by a complementary split-ring-resonator as a 1-cel metamaterial-inspired geometry formed in the PBS to remove the resonance that hinders the signal transfer from one layer to another. The method is verified by the full-wave simulation...
Electromagnetic (EM) simulators are commonly used for electromagnetic compatibility and signal integrity (SI) analysis of printed circuit boards (PCB). The accuracy of such analysis depends on the models used for PCB dielectrics and conductors. These models should be broadband and preserve the physical properties of the materials, such as causality and passivity. One such model for dielectrics is...
On-board networks with different voltage levels are applied in vehicles equipped with an electrical drive system. Voltages in the range of several hundreds of volts are used in the traction (high-voltage; HV) network. Conventional electronic devices are connected to the low-voltage (LV) network. In the automotive industry, where HV components containing sensors, contactors and communication interfaces,...
We derived expressions of power and ground voltage noises for reducing common-mode voltage in a power distribution network of an LSI and found that they have the same amplitude and a phase difference approaching 180°. To confirm this, we performed an experiment using a test board with a cover-metal structure-essentially, a floating conductor in an LSI package to reduce common-mode voltage. The evaluation...
A discrete optimization using a genetic algorithm (GA) for electromagnetic interference (EMI) f ler design is presented in this paper. Using a macro-model in the frequency domain this approach takes into account the load impedance and the source emissions. The macro-model includes an accurate filter model that takes into account the PCB stray elements and the passive components high frequency complex...
Power supply noise generated by integrated circuits is one of the major sources of EM radiation from PCBs. The reduction of power supply noise can be realized by means of devices that bypass the current among power supply planes, such as bypass capacitors, ground vias and so on. In the present work the effect of current bypass devices on the far field radiation from multilayer PCBs is represented...
Resonances in power distribution network are the major cause of voltage fluctuation and noise problems. In this paper, a new method that suppresses impedance peak is proposed. The proposed method uses a high series resistance (HSR) capacitor in parallel to regular bypass capacitors. By selecting the parameters so that the series resonance frequency of the HSR capacitor equals to the anti-resonance...
In this paper, a case study on the merit of adding the LISN for radiated-emission (RE) testing is demonstrated. For this study, a site source is created and considered as the device under test. This site source, activated by AC power, can generate harmonic reference signals ranging from 30 MHz to 1 GHz. The site source is then measured for numerous times. A large variation among these measurements...
This paper describes the results of calculating and measuring deviations of conducted disturbance voltages caused by differences in the arrangement of an artificial mains network (AMN) used to measure the voltage, for example, the height of the (AMN) from a horizontal reference ground plane and the connection between the AMN and the ground plane. The results indicated that the conducted disturbance...
The impact of passive signal integrity (SI) improvement techniques on the radiated emission (RE) for different interconnections between digital devices is presented. In high speed digital integrated circuits, SI is no longer the only issue for desired functional performance. RE is also critical for the functional performance and for compliance with EMC standards. Hence, it is important to understand...
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