共查询到20条相似文献,搜索用时 31 毫秒
1.
Nefyodov E. I. Ponomarev I. N. Zayarny V.P. 《Radiophysics and Quantum Electronics》2021,64(5):347-356
Radiophysics and Quantum Electronics - We solve the problem of excitation of an infinite, perfectly conducting half-plane by an external field in the slot line, which is perpendicular to the edge... 相似文献
2.
The problem of scattering of a plane electromagnetic wave by a perfectly conducting dihedral wedge with a slotted cylinder at the apex in rigorous formulation is reduced to solving a system of linear algebraic equations for unknown coefficients of the Fourier expansion of the scattered field. The results of calculation of the far-zone field with a given accuracy are presented in the case of an E-polarized incident wave. It is shown that for a slot with a large opening angle, the radiation patterns of the field in the long-wavelength far zone has a shape similar to a cardioid and does not depend on the incident-wave direction and the dielectric permittivity of the cylinder. In the case of a narrow slot, the radiation-pattern shape depends significantly on the incidence angle of the wave. 相似文献
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4.
An analytical expression for calculating the wave parameters of a narrow-slot transmission line is found in the quasistatic
approximation. A two-fluid model is used for analyzing processes in a superconducting film of thickness comparable to the
London penetration depth. The wave parameters of the slotted line are calculated under assumptions about the current distribution
near the edges of the slot which are analogous to those used previously for analyzing microstrip and coplanar lines.
Zh. Tekh. Fiz. 67, 94–97 (September 1997) 相似文献
5.
扇形波导可作为高功率微波圆柱共形波导缝隙阵天线的基本单元。分析了扇形波导中主模场分量,根据实际情况对主模场进行了合理近似。采用互易定理推导由波导主模横向场分量和缝隙场分量表示的波导场分量的前向或后向散射系数。根据波导传输线理论,将波导宽边纵缝等效为并联导纳,再根据波导边界条件得到扇形波导宽边谐振纵缝的归一化电导与波导散射系数之间的关系式。根据缝隙天线与振子天线的互补关系得到扇形波导谐振缝隙的辐射阻抗,结合波导功率平衡关系得到由波导横向场散射系数表示的缝隙辐射功率表达式,得到归一化电导的与谐振宽边纵缝的偏移位置、缝隙宽度、波导波长以及扇形波导尺寸参数之间的解析表达式。给出了算例,在波导中间区域,通过商用软件计算得到的电导与理论公式结果基本吻合。 相似文献
6.
扇形波导可作为高功率微波圆柱共形波导缝隙阵天线的基本单元。分析了扇形波导中主模场分量,根据实际情况对主模场进行了合理近似。采用互易定理推导由波导主模横向场分量和缝隙场分量表示的波导场分量的前向或后向散射系数。根据波导传输线理论,将波导宽边纵缝等效为并联导纳,再根据波导边界条件得到扇形波导宽边谐振纵缝的归一化电导与波导散射系数之间的关系式。根据缝隙天线与振子天线的互补关系得到扇形波导谐振缝隙的辐射阻抗,结合波导功率平衡关系得到由波导横向场散射系数表示的缝隙辐射功率表达式,得到归一化电导的与谐振宽边纵缝的偏移位置、缝隙宽度、波导波长以及扇形波导尺寸参数之间的解析表达式。给出了算例,在波导中间区域,通过商用软件计算得到的电导与理论公式结果基本吻合。 相似文献
7.
Antonucci F Cavalleri A Dolesi R Hueller M Nicolodi D Tu HB Vitale S Weber WJ 《Physical review letters》2012,108(18):181101
We present an experimental analysis of force noise caused by stray electrostatic fields acting on a charged test mass inside a conducting enclosure, a key problem for precise gravitational experiments. Measurement of the average field that couples to the test mass charge, and its fluctuations, is performed with two independent torsion pendulum techniques, including direct measurement of the forces caused by a change in electrostatic charge. We analyze the problem with an improved electrostatic model that, coupled with the experimental data, also indicates how to correctly measure and null the stray field that interacts with the test mass charge. Our measurements allow a conservative upper limit on acceleration noise, of 2 (fm/s2)/Hz(1/2) for frequencies above 0.1 mHz, for the interaction between stray fields and charge in the LISA gravitational wave mission. 相似文献
8.
Using the induced magnetomotive force method, we obtain an approximate analytical solution of the problem of diffraction of the H10 mode by a narrow slot which is cut in the impedance finite-thickness wall on the end of a semi-infinite rectangular waveguide and radiates into free half-space over an infinite, perfectly conducting screen. The scattering-matrix coefficients of a slotted waveguide radiator are studied numerically for the values of the complex surface impedance which correspond to some particular types of a thin-film coating of the waveguide end wall. 相似文献
9.
S. O. Shiryaeva 《Technical Physics》2006,51(11):1431-1437
An analytical asymptotic expression for the equilibrium shape of a charged drop of an ideal incompressible conducting liquid uniformly accelerated in collinear electrostatic and gravitational fields is derived in an approximation quadratic with respect to the deviation of the equilibrium shape of the drop from a sphere. It is found that the equilibrium shape of the drop is close to a prolate spheroid when its self-charge and the external electric field strength are far from their values critical in terms of instability against the self-charge and induced charge. This spheroid experiences an insignificant pear-shaped distortion even when the charge of the drop and the electrostatic field strength are high. 相似文献
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11.
S. O. Shiryaeva 《Technical Physics》2006,51(10):1284-1292
An analytical asymptotic expression is derived that describes the equilibrium shape of a charged drop of an ideal incompressible conducting liquid suspended in superposed collinear uniform electrostatic and gravitational fields. The expression is obtained in an approximation quadratic in the small amplitude of deviation of the equilibrium drop from a sphere, with the electrostatic field dimensionless strength taken as a measure of the deviation amplitude. With allowance for the gravitational and electrostatic fields and interaction between the drop self-charge and external electrostatic field, the equilibrium shape of the drop is found to be very close to a spheroid when the charge and the electrostatic field strength are far from their critical values. The analysis is carried out with a refined procedure of calculation of the equilibrium shape of drops placed in external force fields. 相似文献
12.
S. O. Shiryaeva 《Technical Physics》2006,51(3):385-388
The problem of nonlinear vibrations of a charged drop of an ideal incompressible conducting fluid in an electrostatic suspension is analytically solved in an approximation quadratic in two small parameters: vibration amplitude and equilibrium deformation of the shape of the drop in an electrostatic field. To solve the problem analytically, the desired quantities are expanded in semiinteger powers of the small parameters. It is shown that the charge of the drop and the gravitational field influence the shape of the drop, nonlinear corrections to the vibration frequencies, and critical conditions for instability of the drop against the surface charge. At near-critical values of the charge, the shape of the nonlinearly vibrating drop falls far short of being a sphere or a spheroid, which should be taken into account in treating experimental data. 相似文献
13.
A. V. Tyukhtin 《Radiophysics and Quantum Electronics》1997,40(4):259-273
Diffraction of plane electromagnetic waves by a conducting half-plane located in an orthogonal stream of cold plasma is studied.
It is assumed that the half-plane has almost no mechanical effect on the particles of the medium. (For example, the half-plane
can be a model of a metal grid with fairly small cells.) The general solution of the problem has been obtained by the Wiener-Hopf-Fock
technique. The scattering field containing waves of two types is studied analytically and numerically. The behavior of these
waves away from the half-plane edge is analyzed. It is shown that the electric field at the edge is finite, and the shadow
area is absent under certain conditions.
Radiophysical Research Institute of the State University of St. Petersburg., Russia. Translated from Izvestiya Vysshikh Uchebnykh
Zavedenii, Radiofizika, Vol. 40. No. 4, pp. 399–419, April, 1997. 相似文献
14.
This paper describes an experimental study of a quasi-optical cavity to be used in qyrotrons. The cavity configuration was designed so that its output wave could pass into a quasi-optical transmission line. The test cavity was coaxially composed of a pair of annular mirrors, one of which was a curved conical mirror and the other was a plane mirror having a radial slot array for wave output. A mode excited in the cavity at 56.4 GHz was observed by detecting the radiation wave that leaked out through the slotted mirror. It was shown that the present slotted mirror served as a partially and uniformly transparent mirror to radiate the output wave with the same mode as in the cavity. 相似文献
15.
V. M. Serdyuk 《Technical Physics》2006,51(6):777-785
The problem of diffraction of a plane electromagnetic wave by a slot in a planar perfectly conducting arbitrary thick screen with an infinite planar dielectric layer passing through the slot transversely to the screen is solved rigorously. In each of the field existence domains (two domains on either side of the screen and the interior of the slot), the solution is represented as an expansion in piecewise harmonic or exponential modes that allow for reflection and refraction at the boundaries of the dielectric layer. It is found that a set of functions describing such modes is complete enough to construct a solution satisfying all boundary conditions of the diffraction problem. The procedures of solution construction for the case at hand and for the same diffraction structure without the dielectric layer are compared. 相似文献
16.
A quantum-mechanical simulation is carried out to investigate the charge distribution and electrostatic potential along a 1 microm long (5,5) single-walled carbon nanotube under realistic field-emission experimental conditions. A single layer of carbon atoms is found sufficient to shield most of the electric field except at the tip where strong field penetration occurs. The penetration leads to a nonlinear decrease of potential barrier for emission, which is equally responsible for the low threshold voltage besides the well-known geometrical field enhancement factor. 相似文献
17.
A. V. Filippov 《Journal of Experimental and Theoretical Physics》2009,109(3):516-529
The electrostatic interaction of two spherical macroparticles in a plasma has been considered. Primary attention has been
focused on investigating the electrostatic interaction at short distances where polarization effects of the surface charge
of finite-size macroparticles begin to play a dominant role. The first part of this study is devoted to the interaction of
a point charge with a charged conducting sphere in an equilibrium plasma. It has been shown that the presence of a plasma
in the system leads to a decrease in the potential barrier when two like-charged macroparticles approach each other and that
this decrease proves to be the most significant in the case where the macroparticle radius is comparable to the Debye screening
length. The second part of this study is concerned with the interaction of two conducting spheres in the bispherical system
of the coordinates under the assumption that the charges of the conducting spheres are constant and under the assumption that
the surface potentials of the spheres are constant. The latter case is closer to the physics of electrostatic interaction
of two macroparticles in a plasma medium where the electrostatic potential of their surface is determined by the floating
potential of the plasma. It has been demonstrated that the interaction potentials in these two cases are substantially different
from each other and that, at constant macroparticle charges, the energy of the electrostatic field is an interaction potential,
but, in the case of macroparticles with constant surface potentials, which are independent of the interparticle distance,
the energy of the electrostatic field is not an interaction potential. In the latter case, account must be taken of the work
done by external sources on the macroparticle potentials to maintain them constant. The form of the interaction potential
has been established in this case from the analysis of the interaction force in terms of the Maxwell tension tensor. In the
third part of this study, the interaction of two macroparticles has been considered in the spherical system of coordinates
and analytical expressions for the interaction potentials have been derived for both the case of constant macroparticle charges
and the case of constant surface potentials of the macroparticles. 相似文献
18.
We consider the inverse scattering problem for a scalar wave field incident on a perfectly conducting one-dimensional rough surface. The Dirichlet Green function for the upper half-plane is introduced, in place of the free-space Green function, as the fundamental solution to the Helmholtz equation. Based on this half-plane Green function, two reasonable approximate operations are performed, and an integral equation is formulated to approximate the total field in the two-dimensional space, then to determine the profile of the rough surface as a minimum of the total field. Reconstructions of sinusoidal, non-sinusoidal and random rough surface are performed using numerical techniques. Good agreement of these results demonstrates that the inverse scattering method is reliable. 相似文献
19.
Nonlinear asymptotic calculations of the second order of smallness in the amplitude of the initial deformation of an ideally conducting liquid drop show that the laminar flow of an ideal conducting incompressible dielectric liquid flowing about the drop in an external electrostatic field parallel to the flow causes oscillation mode’s interaction in the first and second orders of smallness. Both linear and nonlinear interactions between the oscillation modes of the drop excite modes that are absent in the spectrum of modes governing the initial deformation of the drop’s equilibrium shape. In the second order of smallness, the mode interaction decreases the electrostatic field strength, as well as the velocity and density of the environment, that are critical for development of instability of the drop against the polarization charge. 相似文献
20.
Husnu Deniz Basdemir 《Waves in Random and Complex Media》2018,28(4):700-707
The scattering of plane waves by an impedance half-plane located at the interface of two isorefractive media is investigated. The scattered field, in addition to the diffracted and geometrical optics fields, is analyzed numerically and compared to the scattered field of perfectly conducting half-plane. The effect of the isorefractive media on the scattered field is also examined. 相似文献