This study proposes the Hybrid Filter using the resonanse phenomena of piezoeiectric Transformer to shape the distortion of clock pulse, verifies its performance and estabilishes the design methods of Hybrid Filter. The proposed Hybrid filter is the band-pass filter utilizing Piezoeiectric Transformer and operational amplifier.
In this paper, an electromagnetically coupled printed dipole antenna for measuring electromagnetic fields is designed using the FDTD method. The calculated results compare with experimental results. It is presented that the half-wavelength resonance can be realized by an offset feed. It is also pointed out that the offset feed printed dipole antenna is useful for electromagnetic field sensors.
In this paper, the current distribution of a half-wavelength dipole antenna is estimated from the electric fields near the antenna by the conjugate gradient method. When the distance between the half-wavelength dipole antenna and an electric probe is 3 to 5cm, the estimated currents obtained from measured electric fields agree with the theoretical results.
There has been an increasing interest in effect for electronic equipments and human health by electromagnetic fields radiated from the electronic facileties. In order to understand shielding effect of materials using the metal spray coating technique, measurments have been performed using shielded Enclosure. Main results are shown as below ; (1)In case of paper sprayed coating with metal, the attenuation was almost shown the measurement limit. (2)It is thought that adhesion of metal and the material influenced strongly characteristics of shielding effectiveness. (3)It is possible to apply to construction materials from the improvement of fireproof of the material using the metal spray coating technique.
This paper presents the LSI model to simulate common-mode radiation of printed circuit boards(PCBs)using the FDTD(Finite Difference Time Domain)simulator. Assuming that common-mode radiation is caused because LSIs excite the PCB ground plane, the LSI model have been built, in which the chip and the lead frames of a LSI are modeled respectively by a voltage source and metal wires. To investigate the validity of this model, the measurements of emissions from 4-layer PCBs mounted with a LSI are preformed. The results show that the model, in which the voltage source is placed parallel to the PCB ground plane, can be used to estimate common-mode radiation properties of PCBs. The model can be applied to simulate common-mode radiation of attached-cable PCBs, either. Since it can be used to predict common-mode radiation characteristics of PCBs, using this LSI model would realize the design of LSI packages and PCBs suppressing such radiation.
Internet services using CATV lines are getting into stride. But igress noise degrades upstream transmission quality, so it is necessary to cope with the noise. Though ingress noise is measured using spectrum analyzer generally, this method can't measure impulse noise exactly. We have proposed a new measurement method of ingress noise using amplitude probability distribution. The proposed method avoids the problem mentioned above and has the ability to estimate BER directly.
The reinforced steel bar and the steel frame are commonly used structural materials for the architectural building and also known as ferromagnetic materials. When they are exposed in the strong magnetic field in the process of production, transportaion and so on, it is found that they are sometimes magnetized. The magnetic field generated from these materials causes discoloration of the CRT for the TV-set. In order to prevent this phenomenon, we have investigated the degaussing method for the structural materials using alternative magnetic field. The method proposed in this paper was applied to the floor of the movie studio, and proved to be enough effective to prevent discoloration of the CRT.
A coverage must be studied if the broadcasting in the millimeter waves are considered. This paper shows the result of the coverage in the case of low of transmitting/receiving height and low transmitting power obtained by the computer simulation, which takes 3D building data such as height and width into account. The "coverage for household" for fixed receiving station counts 90 percent, and the "coverage on the road" for mobile receiving station results in 70 percent.