In this paper, a compact multiband printed dipole antenna is presented as a candidate for use in wireless communication applications. The proposed fractal antenna design is based on the second level tent transformation. The space-filling property of this fractal geometry permits producing longer lengths in a more compact size. Theoretical performance of this antenna has been calculated using th...

Department of Electrical & Electronic Engineering, University of Technology P. O. Box 35239, Baghdad, Iraq A new compact narrowband multiresonator microstrip filter design is presented in this paper as a candidate for use in modern wireless communication systems. The proposed filter structure is generated using Peano fractal curve geometry. The proposed filter structure is fractally generated u...

Harmonic functions u : R → R are equivalent to integral manifolds of an exterior differential system with independence condition (M, I, ω). To this system one associates the space of conservation laws C. They provide necessary conditions for g : Sn−1 →M to be the boundary of an integral submanifold. We show that in a local sense these conditions are also sufficient to guarantee the existence of...

We prove an equidistribution theorem à la Bader-Muchnik ([3]) for operator-valued measures associated with boundary representations in the context of discrete groups of isometries of CAT(-1) spaces thanks to an equidistribution theorem of T. Roblin ([22]). This result can be viewed as a von Neumann’s mean ergodic theorem for quasi-invariant measures. In particular, this approach gives a dynamic...

The modal low frequency noise generated by a vibrating elastically supported circular plate embedded into a flat infinite baffle has been examined. The main aim of this study is the analysis of the radiation efficiency. Low frequency approximated formulas have been presented. They are valid for all the limiting boundary conditions of the plate with its edge clamped, guided, simply supported or ...

A posteriori error estimation and related adaptive mesh-refining algorithms have themselves proven to be powerful tools in nowadays scientific computing. Contrary to adaptive finite element methods, convergence of adaptive boundary element schemes is, however, widely open. We propose a relaxed notion of convergence of adaptive boundary element schemes. Instead of asking for convergence of the e...

We derive a decomposition formula for the spectral flow of a 1-parameter family of self-adjoint Dirac operators on an odd-dimensional manifold M split along a hypersurface Σ (M = X ∪Σ Y ). No transversality or stretching hypotheses are assumed and the boundary conditions can be chosen arbitrarily. The formula takes the form SF (D) = SF (D|X , BX) + SF (D|Y , BY ) + μ(BY , BX) + S where BX and B...

The boundary integral method for calculating the stationary states of a quantum particle in nano-devices and quantum billiards is presented in detail at an elementary level. According to the method, wave functions inside the domain of the device or billiard are expressed in terms of line integrals of the wave function and its normal derivative along the domain’s boundary; the respective energy ...

Abstract Temporal discontinuity in a medium’s dielectric properties (temporal boundary) is useful model for considering electromagnetic phenomena dynamic materials and metamaterials. Here counterpart of the Ewald–Oseen extinction theorem classical optics derived light scattering at temporal boundary. In particular, it shown that initial wave its replacement by frequency shifted waves gas-plasma...