Tokoh Nishikubo

RF Magnetic Shielding Effects of a Compound Plate Constructed From Bincho-Charcoal and Ferrite Plates

With rapid development in the field of information technology, there has been increased interest for electromagnetic shielding in the radio frequency (RF) region. An excellent RF magnetic shielding material can be realized by the use of bincho-charcoal, a high quality charcoal found in Japan, due to its very large value of relative permittivity in the RF region. The present paper has improved the RF magnetic shielding characteristics of a bincho-charcoal plate to realize a broadband frequency by the superposition of a ferrite plate over the bincho-charcoal plate. This configuration is termed the compound plate. The RF magnetic shielding effects of the compound plate have been examined, including the characteristics of the RF magnetic effect against both the frequency and the RF magnetic power. In addition, RF electric shielding effects have been examined as functions of the frequency and the RF electric power

Manufacture of an RF Magnetic Shielding Plate Having Orientation Characteristics

As one of the basic areas of research for the improvement of the electromagnetic environment, this paper has developed a carbon plate having orientation characteristics. To exhibit the orientation characteristics in a plane wave, a slit was cut on the surface of a carbon plate. The value of the radio frequency (RF) magnetic shielding degree SD HP when holding the slit in the carbon plate perpendicularly, in the frequency region from 1 MHz to 1 GHz, increased with frequency and had a value of 48 dB at 1 GHz. It was also shown that the value of SD HH when holding the slit horizontally indicated about 15 dB in the frequency region from 1 MHz to 1 GHz. Namely, the difference in the values of shielding degree of the carbon plate versus the orientation of slit indicated the characteristics of the orientation. Experimental results revealed several characteristics of the slit carbon plate that include the influences of the slit length L, slit number N, and slit width w on the characteristics of the orientation. In this paper, the orientation characteristics were improved by the superposition of a slit ferrite plate over a slit carbon plate, termed the compound plate. In addition, important criteria are discussed for the design of a plate for effective RF magnetic shielding having orientation characteristics.

Improvement in the Polarization Characteristics of a Slit Carbon Plate: The Superposition of Slit Ferrite and Copper Plates Over a Slit Carbon Plate

In order to improve the electromagnetic environment associated with the widespread use of electronic devices for communication, computation, automation, among other purposes, the present paper has developed a carbon plate that exhibits polarization characteristics. To achieve polarization characteristics in the far field, slits were cut into the surface of a carbon plate; termed the slit carbon plate. The value of the RF magnetic shielding degree SDHP when holding the slits of the carbon plate perpendicular to the ground, in the frequency region of 140 MHz to 700 MHz, increased with frequency, and displayed a value of 35 dB at 700 MHz. It was also shown that the value of SDHH, when aligning the slits horizontal to the ground, increased with frequency, and recorded a value of 5 dB at 700 MHz. Namely, the difference in the shielding degrees of the slit carbon plate for the orientation of the slits indicated polarization characteristics. In present research, the polarization characteristics of the slit carbon plate were improved, in the frequency region of 1 MHz to 800 MHz, by the superposition of slit ferrite and copper plates over the slit carbon plate; termed compound plate. For example, the difference between the values of SDHP and SDHH for the compound plate at 30 MHz was found to be improved by approximately 50 dB. In addition, important criteria are discussed for the design of a plate having polarization characteristics, for effective RF magnetic shielding.

Fabrication of RF Magnetic Shielding Plate Having the Polarization Characteristics

As one of the basic areas of research for the improvement of the electromagnetic environment, the present paper has developed the carbon plate having the polarization characteristics. To exhibit the polarization characteristics in the far field region, it has formed the slit on the surface of carbon plate. The value of the RF magnetic shielding degree SDHH for holding the slit of a carbon plate horizontally, in the frequency region of 1 MHz to 1 GHz, increased with frequency, and had the value of 58 dB at 1 GHz. Also shown that the value of SDHP for holding the slit perpendicularly indicated about 10 dB in the frequency region of 1 MHz to 1 GHz. Namely, the difference of shielding degrees of the carbon plate to direction of slit is indicated the polarization characteristics. Experimental results revealed several characteristics of the slitting carbon plate that include the influences of polarization characteristics on the slit length L and slit number N. In the present paper, it is improved the polarization characteristics by the superposition of slitting ferrite plate over a slitting carbon plate, termed a compound plate. In addition, important criteria are discussed for the design of an effective RF magnetic shielding plate having polarization characteristics.

Orientation Characteristics in the RF Electric Shielding Effects of Superconducting BPSCCO Plates

As one of the basic areas of research for improvement of the electromagnetic environment by use of a bulk high-critical temperature superconductor (HTS), the present paper has developed a Bi-Pb-Sr-Ca-Cu-O (BPSCCO) plate that displays orientation characteristics of the plane wave. To achieve these orientation characteristics, a slit was cut into the surface of the BPSCCO plate. The values of SDEH and SDEP are defined as the radio frequency (RF) electric shielding degrees when orienting the slit horizontal and perpendicular to the ground, respectively. The shieldings exhibit similar characteristics in the frequency region from 1 MHz (55 dB) to 100 MHz (30 dB). The values of SDEH, in the frequency region of 100 MHz (30 dB) to 3 GHz (52 dB), increased with frequency. The values of SDEP indicated an average value of 30 dB in this frequency region. Namely, the difference in the RF electric shielding degree, SDEH – SDEP, with respect to the orientation of the slit, represents the orientation characteristics. Experimental results revealed several characteristics of the BPSCCO plate that include the dependencies of the orientation characteristics on the length, width, and number of slits. Also examined were the orientation characteristics in the RF magnetic shielding effect of the BPSCCO plate as a function of radio frequency.

Experimental Research on Improvement of the Orientation Characteristics of a Slit Ferrite Plate in the RF Magnetic Field: Superposition of a Slit Carbon Plate Over a Slit Ferrite Plate

As part of the basic research for the improvement of the electromagnetic environment, the present study has developed a ferrite plate having orientation characteristics. To exhibit the orientation characteristics of a plane wave, a slit was cut on the surface of the ferrite plate. The values of the radio frequency (RF) magnetic shielding degree SDHH when holding the slit horizontal to the ground, in the frequency region of 1 MHz (43 dB) to 200 MHz (8 dB), decreased with frequency. The value of RF magnetic shielding degree SDHP when holding the slit perpendicular indicated an average value of 20 dB in this frequency region. Namely, the values of the difference, SDHH - SDHP, indicated an average value of 13 dB as the orientation characteristics. The orientation characteristics of the ferrite plate, however, displayed no orientation characteristics in the frequency region of 200 MHz to 3 GHz. Therefore, in order to improve the orientation characteristics in this frequency region, a compound plate was formed by the superposition of a slit carbon plate over the slit ferrite plate. The values of the difference, SDHH - SDHP, for the compound plate were then improved by approximately 35 dB in the frequency region from 1 MHz to 3 GHz. Experimental results revealed several orientation characteristics of the compound, slit ferrite and carbon plates.

Orientation Characteristics in RF Magnetic Shielding Effects of BPSCCO Plates

As one of the basic areas of research for improvement of the electromagnetic environment by use of a bulk high-critical temperature superconductor, the present paper has examined a Bi-Pb-Sr-Ca-Cu-O (BPSCCO) plate with a slit, which displays orientation characteristics in the RF magnetic shielding. According to the results, the value of the RF magnetic shielding degree SD HP, when orienting the slit of the BPSCCO plate perpendicular to the ground, increased in the frequency region of 1 MHz (20 dB) to 30 MHz (40 dB) , and then reminded approximately constant in the region of 30 MHz to 3 GHz (40 dB). The value of the RF magnetic shielding degree SD HH when orienting the slit horizontally indicated an average value of 15 dB in the region of 1 MHz to 3 GHz. Namely, the difference in the RF magnetic shielding degree, SD HP-SD HH, as related to the direction of the slit represents orientation characteristics. Experimental results revealed several characteristics of the slit BPSCCO plate that include the dependencies of the orientation characteristics on the slit length, slit width, and slit number.

Improvement in the frequency characteristics of RF magnetic shielding: effects of the superposition of two ferrite plates over a BPSCCO plate

A high-critical temperature superconductor (HTS) is ideal for use as an RF electromagnetic shield. As one of the basic areas of research for the improvement of the electromagnetic environment by the use of a bulk HTS as an electromagnetic shield, the present paper has applied a Bi-Pb-Sr-Ca-Cu-O (BPSCCO) plate to the far field region. In the frequency region from 1 to 30 MHz, however, the RF magnetic shielding degree SDH, with an average value of approximately 30 dB for the single BPSCCO plate, is not sufficient enough to shield electromagnetic waves. Accordingly, the present research has improved the frequency characteristics of SDH for the single BPSCCO plate to realize shielding over a broadband frequency region of 1 MHz to 3 GHz by the superposition of two ferrite plates over a BPSCCO plate; termed the sandwiched plate. The frequency characteristics of SDH for the sandwiched plate was improved by an average value of approximately 30 dB over the frequency region of 1 to 30 MHz. Experimental results revealed several characteristics of the sandwiched plate, which include the value of SDH as a function of radio frequency, and the non-dependence of SDH on the value of RF output power.

Evaluation of Plastic Film Thickness Measuring System Using an X-ray Slit Beam

Plastic films have increased rapidly with the use in flat-panel displays, secondary cells, and electronic devices, to make such devices lighter, thinner, and denser. In the present study, the authors describe a new measuring system using an X-ray slit beam with 0.4 mm to measure the thickness of plastic films accurately. By using this system, it can be realized to drastically improve the accuracy for the measurement of plastic film thickness between 10 mum and 1000 mum with highly resolution, resulting in an accuracy of plusmn2.7 % or less for approximately 60 mum thick film. And also, it can be find flaws with highly resolution in the plastic sheet.