• 전기학회논문지
• /
• 제61권4호
• /
• pp.606-611
• /
• 2012

The similarity, analogy and equivalence between the phenomenon due to electric and magnetic dipoles have been discussed in the open literature for different situations. Here we are presenting the numerical proof of the trajectory of leakage electric field due to a semi-infinite electric dipole layer in the external periphery and the electric field in the space between oppositely charged surfaces. The result is also valid for the fringing electric field of a parallel plate capacitor. The result is also proved to be a dual of Amp$\grave{e}$re's law in the electrostatics due to a semi-infinite electric dipole layer.

• Journal of Electrical Engineering and Technology
• /
• 제12권1호
• /
• pp.329-334
• /
• 2017

This paper discusses the near field characteristics of a dipole source located near conducting metallic walls from an electromagnetic compatibility (EMC) point of view. An integral equation for a dipole source near a metallic wall is derived and solved by applying Galerkin's method of moments (MoM). The results show that in the regions outside the dipole source, total electric near fields decrease gradually in magnitude with an increasing field point from the dipole source. But in the regions inside the dipole source, total electric near fields decrease rapidly with a dipole position of $h{\leq}0.3{\lambda}$. For a dipole position of $h{\geq}0.7{\lambda}$, the peaks and nulls of the total near electric field occur periodically in the regions inside the dipole source, and the fluctuation period is almost $0.5{\lambda}$. The worst position for a receptor location is along the z-axis, and a range of a half-magnitude of the maximum near electric field in the principal H-plane is about two times broader than that of the principal E-plane. Experimental measurements are also presented to validate the theory.

• 전자공학회논문지A
• /
• 제33A권12호
• /
• pp.9-15
• /
• 1996

An electric field induced by a point dipole soruce within a conductor-backed lossy dielectric slab above the earth is calculated by anumerical method. the calcualtion is peformed on the plane which is parallel to the conductor plane and containing the point dipole soruce. Computed S$_{21}$ values of two parallel planar dipole antennas and two collinear planar dipole antennas are compared against each other, as well as the electic field magnitudes in those arrangements.

• 한국정보통신학회논문지
• /
• 제17권7호
• /
• pp.1558-1563
• /
• 2013

본 논문에서는 시간영역에서 완전도체 접지평면 위 수직 전기 다이폴에서 방사되는 전자기해석을 통해 전파의 거리에 따른 전파경로손실을 해석하였다. 자유공간에서 수직 전기 다이폴의 해석은 시간영역과 주파수영역에서 많은 연구가 이루어졌으나 본 논문에서는 특히 접지면 위 수직 다이폴을 기지국으로 가정한 전파경로손실특성을 시간영역에서 해석하였으며 접지면의 영향으로 나타나는 근접장의 위치변화와 모바일에서 수신되는 과도응답을 관찰하였다. 본 논문의 결과는 지표면 레이더 및 신호처리 분야에 응용될 수 있을 것이다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1636-1638
• /
• 2007

We report on low-voltage pentacene TFTs with a Al2O3/OTS as a gate dielectric. Improving device characteristics, we performed chemical modification of self-grown Al2O3 surface with an octadecyltrichlorosilane(OTS) self-assembled monolayer(SAM). As the result of this combination, the mobility was improved from 0.3 to $0.45\;cm^2/Vs$. In addition, we examined that the SAM dipole electric field have an influence on gate leakage current, transfer and output characteristics.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2000년도 하계학술발표회
• /
• pp.90-91
• /
• 2000

2차 비선형 현상인 제2고조파(Second Harmonic Generation:SHG)는 electric dipole approximation에 의하면 중심대칭성이 있는 물질에서는 발생하지 않는다. 그러나 표면에 대해서는 그 중심대칭성이 깨져 제2고조파가 발생할 수 있게 된다. 즉 bulk에서는 제2고조파가 나오지 않는 반면, 표면에서는 나오게 된다. 본 연구에서는 electric dipole approximation 이상(예를 들면 magnetic dipole, electric quadrupole)을 고려해 시료의 물리적인 성질을 실제 물질계에 가깝게 기술하고자 했다. (중략)

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제51권11호
• /
• pp.616-621
• /
• 2002

With biological effects by ELF (Extremely Low Frequency) magnetic field generated from power system, the transient magnetic field from electric appliances is a major issue presently. Because the transient magnetic field induces higher current than the power frequency field inside living bodies, transient magnetic field exposure has been much focused. In this paper, it is shown that transient magnetic field from electric home appliances can be characterized as magnetic dipole moment. In this method, the dipole moment vector is assumed by allowing an uncertainty of 6dB in the estimated field. A parameter M that represents biological interaction was applied also. The proposed method was applied to 7 types of appliances (hair drier, heater, VDT, etc.) and their equivalent magnetic dipole moment and harmonic components were estimated. As the results, the useful data for quantifying magnetic field distribution around electric appliances were obtained.

• 자원환경지질
• /
• 제30권5호
• /
• pp.451-458
• /
• 1997

The horizontal magnetic dipole as well as electrical dipole was adopted as a source to compute one-dimensional electromagnetic field behavior in controlled source magnetotellurics. he Cagniard impedances due to horizontal magnetic dipole source, especially phases, showed better frequency characteristics than those due to electric one. The magnetic dipole is inferior to the electric dipole in the point of relatively weak transmitting power at low frequency. But considering high resistivity charateristics of Korean geology, the magnetic dipole source is recommended for the survey up to depth of 500 m. A vector CSMT was introduced to get more reliable data in the area of two- or three-dimensional structures. A software and interpretation technique using polarization ellipses were developed. The technique was tested by synthetic data, which provided theoretical basis of the methodology. Although CSMT has inevitable limitation of investigation depth due to practically possible source-receiver separation, we proposed to use the technique developed in this paper where MT is not available, for example, in extremely noisy area or for shallow target.

• 한국전자파학회지:전자파기술
• /
• 제6권1호
• /
• pp.3-9
• /
• 1995

An isotropic electric-field probe, capable of characterizing and quantifying electromagnetic field, was fabricated. The probe consists of three short dipole antennas, a beam-lead Schottky diode and the high resistive transmission line. In order to get the isotropic response three mutually orthogonal dipoles are configured to form the probe. The probe's short dipole elements allow measurements of electric fields from 300MHz to 2GHz with a flatness of .+-. 2.9dB. The mutually orthogonal dipole configration shows a .+-. 1.2dB deviation in the isotropic response with respect to angle.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
• /
• pp.174-174
• /
• 2001

Purpose： Dimensions of body RF coil composed of 4 rectangular loops for low field open MRI hav been optimized. The design result shows the field inhomogeneity of B1 field below 1.5 dB in the 25 cm DSV can be achieved. Method： Our low field RF coil is composed of 4 rectangular strip loops that assumed to b located at both the bottom and top sides of permanent magnet. All the loops have identica dimensions and current amplitude. First, the inductance of a loop is calculated. Second, the current distribution on the coil strip is calculated by using finite difference time doma method (FDTD). It takes as much as 4 days in FDTD simulation for low frequency RF field That's why the electrical dipole radiation method is used for simulation. With the curren distribution obtained using the FDTD simulation, for various dimensional parameters th magnetic field has been calculated by electric dipole radiation method, where the curren elements are regarded as electric dipole radiation sources. The field pattern from electri dipole radiation is almost same as that from FDTD simulation. Also, it is same as that fro the result using the Viot-Savart equation, for far tone radiation term becomes zero and th Bl field amplitude of near one radiation is the same as the B field due to static current The field homogeneity is calculated in the 25 cm BSV.