The paper suggests a model of dielectric properties of bound water in wet soils. The application of the model to the description of dielectric and radiophysical properties of wet soils in microwave electromagnetic range is considered. The comparisons of theoretical and experimental dielectric constants provided show good reliability of the suggested model.

In an attempt to bridge the gap between theory and applications, this paper brings together a few diverse subjects, and presents them as much as possible in self-contained form. A general perturbation method is developed for calculating the first order effects in quite general bi-anisotropic materials. The advantage of this approach is the feasibility of generating solutions of the Maxwell equations for the complicated media, in terms of well-known solutions for simple media. Specifically, the present study was motivated by a need to provide a theoretical framework for polarimetric glucometry methods, presently under investigation, in the hope of gaining better understanding of the systems and their limitations, as well as suggesting new configurations for acquiring better data. To that end, we chose to analyze gyromagnetic effects in lossless magneto-optical systems. Some representative examples have been chosen, and the obtained results, for various situations involving plane and spherical waves, are discussed. It is shown that the specific configuration of the magnetic fields affect the solutions. Generally speaking, the magnetic fields create new multipoles in the resultant wave fields. Another interesting feature of the present approach is the fact that we get the elementary Faraday rotation effect without resorting to a pair of two oppositely oriented circularly polarized waves, as usually done. Consequently we are able to discuss explicitly complicated situations involving non-planar waves and various external magnetic fields. The penalty is of course the restricted validity of the model to small non-isotropic effects.

The paper presents a new universal formulation of electromagnetic fields in microwave ferrite-dielectric waveguiding structures from the given magnetic field distribution of an external source. The solution is derived from the linearized Landau-Lifshits equation using an orthogonality condition for eigenwaves of a magnetization. The magnetization excited in ferrite is obtained in an electrodynamic, magnetostatic or dipole-exchange approximation, depending on the approximation used for eigenwaves. Results are applied for the formulation and the analytical solution of self-consistent electrodynamic problems of an excitation and a reception of waves in ferrite films by transmission lines of an arbitrary type. Numerical calculations are performed for filters and delay lines on the base of symmetric strip-lines using surface and forward volume magnetostatic waves in ferrite films.

In this paper, a spatial-domain Galerkin's procedure in Method of Moments is applied to analyse a cylindrical-rectangular chirostrop antenna. It is assumed that a single-layer chiral substrate is wrap-fabricated around a conducting core-cylinder and that a perfectly conducting and electrically thin rectangular-cylindrical microstrip patch antenna is mounted on the surface of the chiral substrate. By imposing the boundary conditions on the multiple interfaces and applying the scattering superposition method, a complete expression of dyadic Green's functions (DGFs) has been obtained and the current distribution over the cylindrical rectangular chirostrip antenna has been determined. Various radiation patterns due to such a microstrip antenna in the presence of a chiral substrate are obtained and compared with those in the presence of an achiral substrate, so as to gain physical insight into effects of the chirostrip.

In this paper, radiation patterns of a thin circular conducting loop embedded in a two-layered spherical chiral medium but illuminated by a plane wave are obtained. The method of moments is employed in this work to formulate the current distribution along the circular loop enclosed by the spherical chiral radome shell. The dyadic Green's functions defining electromagnetic fields due to sources in both the outer and inner regions are applied. In the Galerkin's procedure for the method of moments, basis functions used in the work are sine and cosine functions which form a Fourier series. The formulation itself here is quite compact, straightforward, and easy-to-use. Effects of various geometrical and dielectric parameters of the chiral radome shell are discussed. As expected, the role of the spherical chiral radome is again realized as a polarization transformer. Associated with these parameters, waves and fields in such an electromagnetic system are characterized. It should pointed that there existed some mistakes in the literature which did not use the correct Green's functions in the method of moments procedure. This paper aims at correcting the mistake and establish a correct concept in the method of moments analysis.

The integral transform method with the asymptotic extraction technique is formulated to evaluate a Sommerfeld type integral for the analysis microstrip dipole on a uniaxial substrate. The infinite double integral of the asymptotic part of the impedance matrix with triangular subdomain basis function with edge condition can be reduced to a finite one-dimensional integral. This finite onedimensional integral can be easily evaluated numerically after the singular part of the integral is treated analytically. It is demonstrated the efficiency and accuracy of the proposed method to evaluate the asymptotic part of impedance matrix.

The dyadic Green's function for an unbounded anisotropic medium is treated analytically in the Fourier domain. The Green's function, which is expressed as a triple Fourier integral, can be next reduced to a double integral by performing the integration over the longitudinal Fourier variable or the transverse Fourier variable. The singular behavior of Green's dyadic is discussed for the general anisotropic case.

In this paper a method for the analysis of a frequency selective surface (FSS) supported by a bianisotropic substrate is presented. The frequency selective structure is a thin metallic pattern - the actual FSS - on a plane supporting substrate. Integral representations of the fields in combination with the method of moments carried out in the spatial Fourier domain are shown to be a fruitful way of analyzing the problem with a complex substrate. This approach results in a very general formulation in which the supporting substrate can have arbitrary bianisotropic properties. The bianisotropic slab can be homogeneous,stratified, or it can have continuously varying material parameter as a function of depth. The analysis presented in this paper is illustrated in a series of numerical examples. Results for isotropic,anisotropic and bianisotropic substrates are given.

To characterize electromagnetic waves in complex media has been an important topic because of its useful applications and scientific significance of its physical mechanism. Dyadic Green's functions, as a mathematical kernel or a dielectric medium response, relate directly the radiated electromagnetic fields and the source distribution. In terms of the vector wave functions in cylindrical coordinates, dyadic Green's functions in a unbounded and a planar, multilayered gyroelectric chiral media are formulated. By use of the scattering superposition principle and taking the multiple reflections into account, a general representation of the Green's dyadics is obtained. Furthermore, the scattering coefficients of the Green's dyadics are determined from the boundary conditions at each interface and are expressed in a greatly compact form of recurrence matrices. In the formulation of the Green's dyadics and their scattering coefficients, three cases are considered, i.e., the current source is impressed in (1) the first, (2) the intermediate, and (3) the last regions, respectively. Although the dyadic Green's functions for a unbounded gyroelectric chiral medium has been reported in the literature, some of the results are incorrect. As compared to the existing results, the current work basically contributes (1) a correct form of dyadic Green's function for a unbounded gyroelectric chiral medium, (2) the general representation of the dyadic Green's functions for a multi-layered gyroelectric chiral medium, and (3) a convincible and direct derivation of the irrotational Green's dyadic.

In this paper we provide a general formulation for the electromagnetic wave interaction with stratified media and then specialize to slabs of negative isotropic media. The field solutions are obtained in all regions of the stratified medium. The characteristic waves in negative isotropic media are backward waves. We derive the field solutions and show that a Gaussian beam is laterally shifted by a negative isotropic slab. The amount of beam center shift is calculated for both cases of transmission and reflection. Guided waves in stratified media are studied. Placing a linear antenna and all types of Hertzian dipole antennas in a stratified medium, we obtained solutions in all regions. We demonstrate and locate the positions of the perfect images of the antenna sources in the presence of negative isotropic slabs.

This paper presents the applicability of combined microwave (ERS-2 SAR) and optical (Landsat TM) data for surface water quality retrievals. Three surface water quality parameters such as turbidity,Secc hi disk depth (SDD), and suspended sediment concentration (SSC) in the Gulf of Finland are estimated using multivariate approach. The results indicate that the visible bands of TM data are somewhat correlated to SAR signals,b y which SAR can explain 14.4% of the variability in TM2 observations. Multivariate analyses show that SAR has some contribution to derive those parameters if they are somewhat correlated to the water surface oproperties. Although it may be possible to develop algorithms for surface water quality retrievals in which SAR is used as supplementary data to optical observations,it still needs to be refined sufficiently to detect differences within the range of these parameters in the area under study.

The hypothesis of a natural sophisticated RADAR tracking system affecting hornets flight was described, analyzed and developed in previous papers [1, 2] considering their (cuticle) skin complex spike elements arrays shown by electronic microscope pictures. The existence of different spike length arrays and their disposition lead, by analogy with antenna, and radio theory and practice, to the hypothesis of transmitting and receiving phased arrays antennae operating at three different wavelengths in the sub-millimetric bands. The natural photo-and piezo electric generation of energy in the hornets reported previously explain how is generated the Radio Frequency (RF) energy required for the operation of the sub-millimeter wavelength natural RADAR system. However, similar to bats, new computation results show that the operation range of hornets RADAR system is limited to less than 100 m. Recently, investigations have shown that also in the hornet two antennae are located hundreds of spikes which may radiate and detect significant radio energy from their internal photo electric sources and piezoelectric effect. Thus, the existence of three separate sources of radiation and detection enable the application of Direction Finding (DF) communication additional hypothesis. The DF concept can contribute to explain how male hornets track the queens and how workers can be guided to theirnest even forop eration distances up to a few kms. It is possible that the results of the proposed investigations will provide tools to improve real tracking and DF systems performances especially in the yet not sufficiently explored submillimeter wavelength ranges and to find applications to this novel hornet property. Soon will be published results and analysis of experiments contributing to prove this fascinating hypothesis.

In this paper, a trial of probabilistic signal processing which is possible to give methodological suggestion to some quantitative measurement method of compound and/or ac-cumulation effect in electromagnetic (abbr. EM) environment is discussed. In order to extract various types of latent interrelation characteristics between many of waved environmental factors (EM and sound waves) leaked from VDT in a real working situation, some extended regression system model reflecting hierarchically not only linear correlation information of the lower order but also nonlinear correlation information of the higher order is firstly introduced. Especially, differing from the previous study, all regression parameters of this model are identified by positively utilizing information of a background EM noise instead of eliminating it. Then, some evaluation method for predicting a whole fluctuation distribution form from sound to EM is newly proposed. Finally, the validity and effectiveness of this proposed method are partly confirmed through some principle experiment too by applying it to the actually observed data leaked by a VDT playing some television games in the room of an actual working environment.

The inverse scattering of buried dielectric cylinders by transverse electric (TE) wave illumination is investigated. Dielectric cylinders of unknown permittivities are buried in one half space and scatter a group of unrelatedTE waves incident from another half space where the scattered field is recorded. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity are circumvented, and the permittivity distribution can be reconstructedthrough simple matrix operations. The algorithm is basedon the moment methodandthe unrelatedillumination method. Numerical results are given to demonstrate the capability of the inverse algorithm. Goodreconstruction is obtainedev en in the presence of additive random noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated.

In this paper, the radiation characteristics of an open circular waveguide asymmetrically covered by a layered dielectric hemi-spherical radome are analyzed. On the waveguide opening, the dominant TE11 wave of the circular waveguide is assumed. The technique of dyadic Green's function is applied to obtain the radiated electromagnetic fields due the circular aperture. Huygens' equivalence principle and the image theory are utilized to simplify the problem. The translational addition theorems of spherical vector wave functions are also employed to make the mathematical representation of the radiated fields compact. Both the exact formulation in the near (radiating-field) zone and the approximate expressions in the far (Fraunhofer) zone of the radiated fields are obtained. Numerical computations are implemented to show the effects of the off-centered source feed asymmetrically covered by the hemi-spherical dielectric radome.

This paper presents an alternative analysis of obtaining radiated electromagnetic (EM) fields in a dielectric prolate spheroid using the perturbation technique. A circular loop antenna is used as a radiator on the top of the spheroid. The spheroid is approximated by the first a few terms of the Taylor series expansion (higher-order approximation), and coefficients for transmission and scattered EM fields are found using the perturbation method where the coefficients are also expanded into Taylor series and determined by matching the boundary conditions on the spheroidal dielectric surface. After the approximated coefficients and EM fields are obtained, validity of the approach is discussed and limitations are also addressed.

We discuss the problem of the reconstruction of the profile of an inhomogeneous object from scattered field data. Our starting point is the contrast source inversion method, where the unknown contrast sources and the unknown contrast are updated by an iterative minimization of a cost functional. We discuss the possibility of the presence of local minima of the nonlinear cost functional and under which conditions they can exist. Inspired by the successful implementation of the minimization of total variation and other edgepreserving algorithms in image restoration and inverse scattering, we have explored the use of these image-enhancement techniques as an extra regularization. The drawback of adding a regularization term to the cost functional is the presence of an artificial weighting parameter in the cost functional, which can only be determined through considerable numerical experimentation. Therefore, we first discuss the regularization as a multiplicative constraint and show that the weighting parameter is now completely prescribed by the error norm of the data equation and the object equation. Secondly, inspired by the edge-preserving algorithms, we introduce a new type of regularization, based on a weighted L2 total variation norm. The advantage is that the updating parameters in the contrast source inversion method can be determined explicitly, without the usual line minimization. In addition this new regularization shows excellent edge-preserving properties. Numerical experiments illustrate that the present multiplicative regularized inversion scheme is very robust, handling noisy as well as limited data very well, without the necessity of artificial regularization parameters.

In this paper, the characteristics of a small antenna using an H-shaped microstrip patch are studied. Significant reduction of antenna size can be realized when the H-shaped patch is used instead of the conventional rectangular microstrip patch antenna. The theoretical analysis is carried out based on the finite-difference timedomain (FDTD) method. The FDTD programs are developed and validated by available measurement results. The effects of various antenna parameters on the resonant frequency and radiation patterns are shown. Several design curves are presented, which are useful for practical antenna design. The electric current distributions on the patch and those on the ground plane are described, together with the results illustrating the electric field distributions under the patch. This antenna is suitable for applications where small size and broad beamwidth are required.

A fast and efficient method for analyzing an inset dielectric guide is presented using the Fourier transform technique with a modified perfectly matched boundary. In order to deal with an open region, a novel idea, modified perfectly matched boundary condition (PMB), has been proposed. By introducing the modified PMB, the numerical integral has been avoided and the accuracy of the numerical solution has been improved. Moreover, the singular behavior of the fields at metal edge is taken into account in the analysis. The numerical examples are shown that the convergence of the solution is very fast and the relative error less than 0.07% is attained even if only the first term is considered in the field expansion of the guide. The numerical results of the propagation constants for single- and double-layered inset dielectric guides agree well with those of literatures.

This paper presents a method of moments (MoM) analysis, obtains the non-uniform current distribution in closed form, and computes the resulted radiated patterns in both near and far zones, of square and rectangular loop antennas with electrically larger perimeter. An oblique incident field in its general form is considered in the formulation of the non-uniform current distributions. In the Galerkin's MoM analysis, the Fourier exponential series is considered as the fulldomain basis function series. As a result, the current distributions along the square and rectangular loops are expressed analytically in terms of the azimuth angle for various sizes of large loops. Finally, an alternative vector analysis of the electromagnetic (EM) fields radiated from thin rectangular loop antennas of arbitrary length 2a and width 2b is introduced. This method which employs the dyadic Green's function (DGF) in the derivation of the EM radiated fields makes the analysis general, compact and straightforward in both near- and farzones. The EM radiated fields are expressed in terms of the vector wave eigenfunctions. Not only the exact solution of the EM fields in the near and far zones outside √a2 + b2 are derived by the use of the spherical Bessel and Hankel functions of the first kind respectively, but also the inner regions between a and √a2 + b2 are characterized by both the spherical Bessel and Hankel functions of the first kind. Validity of the numerical results is discussed and clarified.