We analyze the impact of matching network on compact multiple-input multiple-output systems. Existing studies have found that has a significant influence performance multiple antenna systems when antennas are in close proximity. However, none examined wide-band case. In this paper, we investigate four different networks for dipole antennas. The is given terms bandwidths correlation and efficiency, which extensions single-antenna concept bandwidth to also propagation conditions bandwidth. For...

A recent approach to physical bounds on antennas of arbitrary shape is numerically illustrated. In particular, for circumscribed by the rectangular parallelepiped, finite cylinders, and planar rectangles are presented. The verified against numerical results various small with excellent agreement.

In this paper, physical limitations on bandwidth, realized gain, Q -factor and directivity are derived for antennas of arbitrary shape. The product bandwidth realizable gain is shown to be bounded from above by the eigenvalues long-wavelength, high-contrast polarizability dyadics. These dyadics proportional antenna volume easily determined an geometry. Ellipsoidal volumes analysed in detail, numerical results some generic geometries presented. theory verified against classical Chu spherical...

This is the first part of a series papers devoted to direct and inverse scattering transient waves in lossy inhomogeneous media. The medium assumed be stratified, i.e., it varies only with depth. wave propagation modeled an electromagnetic case spatially varying permittivity conductivity. objective this paper analyze properties operators (impulse responses) for introduce reader problem, which subject second series. In particular, imbedding equations are derived corresponding reviewed. kernel...

In this paper, new physical limitations on the extinction cross section and broadband scattering are investigated. A measure of in terms integrated is derived for a large class scatterers based holomorphic properties forward dyadic. Closed-form expressions given homogeneous ellipsoids, theoretical bounds discussed arbitrary heterogeneous scatterers. Finally, results illustrated by numerical computations series generic

The one-dimensional inverse scattering problem for inhomogeneous lossy media is considered. model involves electromagnetic wave propagation in a medium of unknown thickness with spatially varying conductivity and permittivity. Two inversion algorithms are developed the time domain using data obtained from normally incident plane waves. These utilize reflection both sides medium, one them also uses transmission data. implemented numerically on several examples, which includes effects noisy...

Receive diversity gain performance of a two-antenna setup in an office environment is reported. The terminal handheld front the user simulating data mode scenario while walking around. dual polarised base station sector antenna placed at end corridor. results indicate that experimentally achieved similar to previously predicted theoretical data.

The direct scattering problem for an inhomogeneous lossy medium is examined the one-dimensional case in which phase velocity profile discontinuous at boundaries of medium. Scattering operators (or impulse responses) and propagation are defined equations that govern their behavior developed. Knowledge kernels one round trip implies can be determined on any time interval. Numerical examples presented. It also shown this reducible to there no mismatches. This reduction provides considerable...

Using Bloch waves to represent the full solution of Maxwell's equations in periodic media, we study limit where material's period becomes much smaller than wavelength. It is seen that for steady state fields, only a few contribute solution. Effective material parameters can be explicitly represented terms dyadic products mean values nonvanishing waves, providing new means homogenization. The representation valid an arbitrary wave vector first Brillouin zone.

The T matrix for scattering of waves by a circular disk is derived. Both the scalar (Dirichlet and Neumann boundary conditions) vector (perfectly conducting disk) cases are considered use alternative choices surface field functions discussed in detail, it found that either type representation equally good case. Analytic expression farfield amplitude total cross section given low-frequency limit both plane-wave incidence or point source. Numerical results presented two as well perfectly disk....

In this paper we introduce an approach to analyze the interaction between antennas and propagation channel.We study both channel by means of spherical vector wave mode expansion electromagnetic eld.Then use coecients some properties general in those elds antenna scattering matrix.The focus is on spatio-polar characterization antennas, channels their interactions.We provide closed form expressions for covariance eld multi-modes as function Power Angle Spectrum (PAS) cross-polarization ratio...

This paper focuses on propagation of transient electromagnetic waves in waveguides general cross section with perfectly conducting walls. The solution the wave problem relies a splitting technique, which has been frequently used direct and inverse scattering problems during last decade. field waveguide is represented as time convolution Green function excitation. Some numerical computations illustrate method. A new way calculating first precursor Lorentz medium presented. method, not based...

For pt.III see J. Math. Phys., vol.28, p.260 (1987). The one-dimensional inverse scattering problem is considered for lossy inhomogeneous media the case in which phase velocities at two boundaries of scatterer do not match that host medium. model involves electromagnetic wave propagation a medium unknown thickness with spatially varying permittivity and conductivity. An inversion algorithm capable simultaneously reconstructing both conductivity derived tested numerically. It shown...

A dispersion relation for the combined effect of scattering and absorption electromagnetic waves is presented a large class linear passive material models. By invoking optical theorem, result states that extinction cross section integrated over all frequencies equal to static limit volume. The present paper focuses on an attempt experimentally verify this sum rule by measuring monostatic radar fabricated sample metamaterial. In particular, utilizes idea that, specific targets, scattered...

We will in the present paper derive a general three-dimensional formalism for electromagnetic scattering from buried inhomogeneities. exploit transition matrix formalism, originally given by Waterman, to presence of an infinite surface and bounded inhomogeneity. The analysis explicitly assumes that sources are located above ground, but this restriction can easily be relaxed parallel derivation made ground or inside obstacle. No explicit symmetry assumptions inhomogeneity interface between...

A limitation on the extinction cross section, valid for all scatterers satisfying some basic physical assumptions, is investigated. The obtained from holomorphic properties of forward scattering dyadic. analysis focuses consequences materials with negative permittivity and permeability, i.e. metamaterials. From a broadband point view, limitations imply that there no fundamental difference between metamaterials ordinary respect to absorption. illustrated by three numerical examples modelled...