Takashi Sakusabe

The Current‐Voltage Characteristics of a Photoelectrochemical Cell Using p‐Type Porous Si

Fundamental characteristics of a photoelectrochemical cell using p-type porous-Si layer (PSL) as a semiconductor photoelectrode were measured. The PSL electrode exhibited stable photodiode characteristics. The increase in the PSL thickness was very useful in suppressing the dark current, although it resulted somewhat in reducing the photosensitivity, due to the increase in surface recombination losses of photogenerated carriers.

Study on noise reduction effect using the decoupling capacitor with resistor on power distribution line

The purpose of this study is to estimate the switching noise reduction effect by using the decoupling capacitor with resistor. By attaching several decoupling capacitors in parallel in the circuit, new anti-resonance peaks appear and it prevents the noise reduction effect. The use of decoupling capacitor with resistor can promise to reduce resonance effects. In this study, the effects of decoupling capacitor with resistor were investigated when it attached to the power-ground line. For the experimental convenience, microstrip line was employed as a power-ground line and input impedance and radiation of the line with the decoupling capacitors were calculated and measured. From the experimental results, though the impedance of decoupling capacitor with resistor is much higher than that of decoupling capacitor without resistor the radiation profile is almost same and peaks at resonant frequencies are dumped.

EMC constraint PCB design support tool-assistance for power and ground trace wiring

For printed circuit board (PCB) design using computer aided design (CAD), a design assistance system for reduction of electromagnetic interference is developed. In the present system, a manual design of PCB power-ground interconnection is assisted visually based on the EMI reduction rule. In this paper, the system configuration of the support tool and its application for power-ground trace wiring is demonstrated. The tool can help the layout designer interactively and visually.

Electromagnetic interference from printed circuit boards connected by flexible printed circuit board

Flexible printed circuit (FPC) has used for the 3D wiring in the electronic equipment. PCBs are often located in 3D and connected by FPC to make the electronic device small. In this case the PCBs are faced each other in small distance and have electromagnetic interference. This causes deterioration of transmission property at high frequency and electromagnetic noise radiation. In this study, electric radiation and transmission property of the PCBs connected by FPC are calculated using 3D electromagnetic solver. From the results, it is found that resonant frequencies are shifted by mismatch of the characteristic impedance and of balance mode of the lines. And new radiation peak appears at the frequency corresponding to the distance between the faced PCBs.

Study on measurement uncertainty in immunity testing: IEC61000-4-6

Factors of the measurement uncertainty (MU) are analyzed and calculated, to examine a dominant MU factor in the IEC/EMC immunity standard such as IEC61000-4-3,-6 etc., in accordance with ISO guide 17025 describing uncertainty in measurement. It was assumed that the contribution factors to MU are the measurement system repeatability, accuracy of the signal generator, amplifier gain and harmonics, accuracy of the oscilloscope, mismatch, modulation, and test-setup. From the experimental result, it was obtained that the most important uncertainty factor was ldquotest setuprdquo. This means that ldquosetuprdquo influences the test-level. Therefore, we suggest that if application of the uncertainty is effectively done, it is necessary to define the setup clearly.

On the radiation from nonequi-length paired cable

The radiation from the nonequi-length paired cable was investigated theoretically and experimentally. The research reveals that the radiation spectrum has peaks, which locate at the resonance frequencies where not excess short line but total longer line length corresponds to n /spl lambda//2, even in case of matching termination. It is due to the common mode radiation.

Radiation from and current distribution on plane conductor

Plane conductors with a dipole antenna configuration are excited by disturbance sources. Far-field radiation, magnetic near field and current flow on the plane, and input impedance are analyzed numerically and experimentally. For the open-end structure, the current flows along the edge of the plane. The current path is equivalent to half of the wavelength, at the frequency corresponding to which the input impedance has minimum.

Performance of the phototube in which the photoelectron train is stretched to extend the timebase

To observe a waveform of a very fast photoevent, a special phototube is developed. A short photoelectron train produced by the incident light from the photoevent is stretched during its runs through a long drift electrode of the phototube due to the difference of the velocity of each photoelectron which is instantaneously accelerated by a step voltage of the photocathode rapidly raised during the light incidence. In order to discuss the limitation of the stretching operation the performance of the phototube such as spreading of the pulse width, influence of the electron lens, both induction noise and random noise are described. As a consequence the time resolution is estimated to about 10 ps at present.