A bsrrucr-This study reports on the performance of a thin-film magnetic sensor which uses the h i g h frequency magneto-impedance (HFMI) effect. I n order to obtain a high sensitivity and a large voltage change ratio (AVpp/Vpp(O) : corresponds t o the MR ratio), a strip pattern, a closed magnetic circuit, and a NiFe/Si02 multilayer film structure are adopted for the magnetic films of the sensor. A AVpp/Vpp(O) of 60-70 % is achieved by applying a n external magnetic fieid of several Oe. Moreover there is no hysteresis or no Barkhausen noise i n this sensor, which has a magnetic film width of 1 0 pm. In terms of linearity, the sensor exhibits a modulation degree ( m ) of 12 %and a total harmonic distortion (THD) of 0.8 %.

This letter describes the effect of Ag addition on the surface resistance of sintered YBa2Cu3O7-x superconductors at 17 and 50 GHz. The surface resistance decreases more than 50% by adding Ag into a pellet or a thick film of YBa2Cu3O7-x . The thick film exhibits a surface resistance of 22 mΩ at 17 GHz and at 77 K, which is almost equal to that of pure Cu. It is also revealed that the surface resistance is proportional to the square of the frequency. These phenomena are discussed in terms of the effect of Ag on the morphologies and c-axis orientation of YBa2Cu3O7-x grains.

Abstract-In this paper, the authors introduced a new approach to realize a contact-free micro-bearing for MEMS (Micro-Electro-Mechanical-Systems) applications. In the proposed idea, the mechanism of magnetic repulsion by eddy current was employed. Numerical analysis and experimental research was performed. In the proposed structure having a ringed magnetic circuit having a circularly-arranged gap (gapped-core), the generated magnetic flux was concentrated with high density and showed precipitously gradient in the magnetic field and also showed a larger of repulsive force comparing to the general electromagnetic (iron-core). Advantage of the proposed method and its viability as a contact-free Micro-bearing was discussed.

This paper describes the application of a Co-based amorphous alloy ribbon to a common-mode noise filter in the 1 MHz–1 GHz frequency range. Its saturation magnetization, and relative permeability were 6000 G and 1450, respectively. The 10-μm-thick amorphous ribbon exhibits high loss characteristics. The resistance of a 2-mm-diam roll of amorphous ribbon (12.5 mm wide and 30 cm long) increases from 3 Ω at 1 MHz to 50 Ω at 350 MHz. It is confirmed that a filter 1/17th the volume of a conventional (ferrite core) filter exhibits the same noise attenuation. Moreover, the noise emission from a twisted pair cable is greatly reduced without any increase in the cable volume by employing the amorphous ribbon as a shielding material.

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