V. N. Semenenko

Development and simulation of microwave artificial magnetic composites utilizing nonmagnetic inclusions

Abstract The paper deals with the selected results of investigation of composite materials exhibiting artificial magnetic properties at microwave frequencies owing to the resonant phenomena in nonmagnetic inclusions. In particular, inclusions are investigated in the form of small (compared with the wavelength) dielectric particles prepared of a material of high permittivity and wire helixes of different shapes. It is demonstrated that the composites exhibit effective magnetic properties in the vicinity of the eigenfrequencies of the inclusions. The frequency dispersion of the effective magnetic permeability of such materials is resonant. It is demonstrated that conducting helical inclusions may be used to prepare composite materials characterized, in some frequency band, by the negative values of the real parts of the permeability and permittivity simultaneously. The properties of unusual “left-handed” (V.G. Veselago) materials are discussed. A numerical simulation of the electromagnetic properties of such composites is performed. The calculated effective parameters turn out to be close to the measured values.

Wide-angle Absorption by the Use of a Metamaterial Plate

The problem regarding top possible (hopefully, total) fleld suppression of a fll- amentary source placed above nonuniform impedance plane is discussed. New designs of the electromagnetic fleld absorbers and resonators are suggested which may be engineered with the use of metamaterials. 1. INTRODUCTION | ABSORPTION OF THE ENERGY OF A POINT SOURCE BY A HALF-SPACE Interest to the fleld propagation along the imperfect surface has about century-old history, the beginnings of which trace back to the Sommerfelds solution of the classical problem for the dipole radiating above the plane with flnite conductivity. Later, as the radio broadcasting evolved, a lot of publications appeared which dealt with electromagnetic fleld propagation in the presence of an absorbing half-space with the aim to minimize the signal losses. Now certain practical needs (1) set questions about what value of impedance of a plane should be chosen to absorb the maximum portion of energy radiated by a point source (say, fllamentary current), how much the amount of the absorbed energy is and how to create such an impedance. Note, in view of the symmetry of the radiation pattern of the fllament, at the absence of the plate (in the free space) equal power ∞uxes are radiated into upper and lower half-spaces, and exactly one half of the radiated energy penetrates through the plane y = 0, see Fig. 1.

Abnormal Radiation Pattern of Metamaterial Waveguide

The idea to inverse the radiation pattern of the microwave antenna due to appli- cation of the isotropic metamaterial screen with negative refractive index in S band is demon- strated at the flrst time in this investigation. The electromagnetic simulation of waveguide antenna patterns by moments methods demonstrates an agreement modeling antenna patterns with measured antenna diagrams for values of metamaterial efiective parameters (permittivity and permeability) extracted from measured S-parameters of metamaterial sheet sample.

Measurement methods of complex permittivity and permeability of sheet samples in free space in microwave range

A set of measurement methods of complex permittivity and permeability of sheet samples in free space in microwave range is elaborated. The measurements are realized in wide frequency band for comparatively small samples (compared to several wavelengths) with high accuracy due to using of Time Domain and compensation procedure on diaphragmatic horn antennas.

Electrophysics and electrodynamics of metamaterials

This paper generalizes the main results obtained at the Institute for Theoretical and Applied Electromagnetics of the Scientific Association for High Temperatures of the Russian Academy of Sciences in the design and study of materials with new properties that have no analogs in nature, i.e., the so-called metamaterials. The brief review covers investigations performed since 1987 up to now. It has been demonstrated that new properties of metamaterials are associated with the resonance phenomena, which arise in the propagation of electromagnetic waves in a heterogeneous medium filled with inclusions of special shape. The fundamental aspects of the problem and some of the possible applications have been discussed.

Radar Absorbing Materials Based on Metamaterials

The use of metamaterial for design of radar absorbing material (RAM) is discussed. The typical features of the frequency dependencies of , , ,  of composites manufactured of different types of resonant inclusions are given as an example. The RAM characteristics obtained by the use of the composites are given. It is shown that it is possible to use for RAM design the metamaterials with both the positive values of ,  and negative ones. Making use of the frequency band with negative  and  it is possible to create a RAM with low reflection coefficient in a wide range of the angles of electromagnetic wave incidence.

Experimental Definition of Dipole Resonator Polarizability

Presented in this paper is the technique for calculation of magnetic and electric polarizability of dipole resonators using experimental results. It was determined good coincidence between the measured and calculated polarization values, that proves the technique correctness

Perspective composites based onwire helix inclusions

The paper deals with the selected results of investigation of composite materials exhibiting artificial magnetic properties at microwave frequencies owing to the resonant phenomena in nonmagnetic inclusions. In particular, inclusions are investigated in the form of small (compared with the wavelength) wire helixes of different shapes. It is demonstrated that the composites have effective magnetic properties in the vicinity of the eigenfrequencies of the inclusions. The frequency dispersion of the effective magnetic permeability of such materials is resonant. The applications of such composites for antenna techniques are presented

Setup for measurement of complex permittivity and permeability of sheet materials in the horn near zone

Described in this paper is the setup for measurement of complex permittivity and permeability of sheet materials in the horn near zone. The measurements can be made for small samples (compared to several wavelengths) with high accuracy due to special calibration and compensation procedure