A problem of electromagnetic wave scattering from ferrite post is presented. The post is assumed to be located in closed areas as waveguide junction, or in open area illuminated by a plane wave. The object is of arbitrary convex cross section and the method of analysis is semi-analytical, based on the direct ﬁeld matching technique.
Spectral domain approach is modified and used to analyze some simple structures containing graphene strips. The modification is simple and concerns the Green’s function only. Moreover, the method is combined with the recently published root finding algorithms, which significantly improve the efficiency of the analysis. The results obtained for a simple guiding structure is verified and the field displacement effect is confirmed.
The analogies between the behavior of gyromagnetic and gyroelectric nonreciprocal structures, the use of the simple transfer matrix approach, and the edge-guided (EG) wave property, supported in a parallel plate model for integrated magnetized semiconductor waveguide, are investigated in those frequency regions, where the effective permittivity is negative or positive. As with their ferrite counterparts, the leakage of the EG waves along the curvilinear semiconductor-metal edge is observed for those frequencies where the effective permittivity is positive. This induces spurious resonances in the semiconductor junctions having a convex–concave geometry. Furthermore, the very small reflection from the open semiconductor edge is observed for those frequencies where the effective permittivity is negative. This provides the unidirectional wave propagation in the parallel plate semiconductor (PPS) guide where one edge is open as well as in the PPS guide inserted into a dc magnetic antiparallel field. Hence, as a practical application, new EG mode nonreciprocal semiconductor devices are proposed as complementary to the already known ferrite versions. The simulated characteristics of the ideal junction and their implementation in finline technology clearly illustrate their broadband, nonreciprocal operation in the millimeter-wave regions (25–250 GHz), something which is difficult to achieve with ferrite devices
In this paper, a periodic dielectric/metallic rod is located in a circular waveguide to obtain left-handed operation. Two geometries of the dielectric/metallic rod are proposed and examined. The dispersion characteristics of the investigated waveguides are obtained using a surface impedance model. Moreover, equivalent circuit models are proposed allowing for calculation of the dispersion characteristics and scattering parameters of the considered waveguide structures. The numerical results are compared with those obtained from commercial software and from experiment. The obtained results prove the left-handed properties of the investigated structures.
In this paper the nonreciprocal properties of el-liptical ferrite coupled line (EFCL) junction are examined. In the analysis the technique combining spectral-domain approach (SDA) with coupled-mode method (CMM) is applied. The nu-merical results concerning gyromagnetic coupling coefficient of ferrite coupled lines and scattering matrix of EFCL junction are presented. The obtained results are validated with the use of commercial software Ansoft HFSS.
The paper presents the research on a rectangular microstrip structure with multilayer substrate containing dielectric and omega medium layers. The effect of pseudochiral medium layer location in the substrate and its thickness on the resonant frequency of the rectangular microstrip structure is investigated. The numerical analysis of investigated structures is based on expansion of electric and magnetic ﬁelds. Utilizing the continuity conditions the boundary problem is formulated which is solved with the use of method of moments.
A method of moments combined with mode matching technique is applied to analyze the shielded coupled strip and slot line structures containing a thin plate of Omega pseudochiral medium. The boundary problems are simplified by introducing for omega medium the approximate continuity conditions. Such mathematical model allows to examine the field displacement effect appearing in the considered guide resulting from the coupling between the omega medium and modal fields. This effect has different influence on the wave parameters of the modes propagating in the coupled strip and slot guides. The phenomena occurring in the investigated structure can be applied to the design of the novel devices such as couplers or filters.
A configuration of multistrip lines mounted on a multilayer dielectric coated elliptic cylinder is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. Both open and shielded lines are considered in the analysis. Propagation coefficients and characteristic impedances are calculated for the lines with different ellipticity. The results are verified by comparing them with those obtained from commercial software.
This chapter presents authors’ recent research on the nonreciprocal devices utilizing longitudinally magnetized ferrite coupled line (FCL) junction. The principle of operation of FCL junction is explained and the hybrid techniques of analysis are shown. Numerical and experimental results concerning the nonreciprocal devices utilizing the different configurations of FCL junctions are presented and discussed.
A rectangular microstrip structure with multilayer substrate containing dielectric and pseudochiral medium layers is studied in this paper. The effect of Omega medium layer location in the substrate and its thickness on the complex resonant frequency of the rectangular microstrip structure is investigated.