A numerical method is presented for the analysis and design of a wide variety of electromagnetic (EM) structures consisting of dielectric and conducting parts of arbitrary shapes. The method is based ...on the integral-equation formulation in frequency domain, and represents a large domain (high-order expansion) Galerkin-type version of the method of moments (MoM). The method is formulated in two versions concerning the type of the equivalence (volume and surface) utilized in the treatment of the dielectric parts of the structure. The generality, versatility, accuracy, and practicality of the method and code are demonstrated on four very diverse, electrically large, and complex EM problems. The examples are: an X-band reflector antenna modeled after a bat's ear, which is about 11/spl lambda//sup 3/ large at X-band; a broad-band (0.5-4.5 GHz) nested array of crossed loaded dipoles; an EM system consisting of a dipole antenna and a human body, and a broad-band (1-5 GHz) microstrip-fed Vivaldi antenna with a high-permittivity dielectric substrate. The central processing unit times with a modest personal computer are on the order of several minutes for a single-frequency application.
Broadband quasi-microstrip antenna Popovic, B.D.; Schoenberg, J.; Popovic, Z.B.
IEEE transactions on antennas and propagation,
10/1995, Letnik:
43, Številka:
10
Journal Article
Recenzirano
A new printed microwave antenna is presented. The antenna is a hybrid between a wire antenna array and a microstrip patch antenna. Although the size, cost, and efficiency are comparable to the ...microstrip patch, the voltage standing wave ratio 2:1 bandwidth of the antenna presented here is above 20%. The radiation pattern of the antenna does not change appreciably within the bandwidth, and the theoretical efficiency for optimal antennas remains above approximately 80% within the bandwidth. Measurements on several antennas around 2 and 4 GHz are presented, as well as theoretical results obtained using a full-wave analysis.< >
Several new excitation and load models are proposed for electromagnetic analysis in the context of a Galerkin-type large-domain (higher-order) boundary element method (BEM) or Method of moments for ...structures composed of thin wires, metallic surfaces, and imperfect inhomogeneous dielectric bodies. The models represent a natural generalization of point-delta generators and loads for wires. They are used for excitation and loading of metallic quadrilateral surface elements and dielectric hexahedral volume elements, and are termed line-delta and surface-delta generators and loads, respectively. The corresponding Galerkin generalized impedance and voltage matrix elements are derived and incorporated in the large-domain BEM outlined in the paper. The accuracy and usefulness of the proposed excitation and load models are illustrated on a number of characteristic examples. It is believed that these models can also be included in other BEMs for analysis of electromagnetic systems in frequency domain with comparable advantages.
A numerical method is presented for the analysis and design of a wide variety of electromagnetic structures consisting of dielectric and conducting parts of arbitrary shapes. The method is based on ...the integral-equation formulation in frequency domain, and represents a large-domain (high-order expansion) Galerkin-type version of the method of moments (MOM). The method is formulated in two versions concerning the type of the equivalence (volume and surface) utilized in the treatment of the dielectric parts of the structure. It is demonstrated on two unconventional examples that a well designed and carefully optimized moment-method can be a highly efficient and reliable tool for numerical solutions of real-world problems.
In this work, a method for predicting the effect of conductive plates and boxes on electrical circuit behavior is presented. The method uses the Hallen integral equation to determine currents along ...circuit branches. The effect of metal packages is taken into account with appropriate images of the circuit branches. Using image theory enables time-efficient approximate full-wave analysis. This approach allows the analysis of circuits placed above a single ground plane, in a metal corner, between parallel metal planes, in rectangular metal pipes or in rectangular metal boxes. The circuits can be made of possibly insulated metal wires and/or narrow strips printed on thin dielectric substrates, and can have lumped generators and lumped or distributed impedances. The method is illustrated on several simple circuit examples and the results are compared to measurements and to results obtained using circuit theory.< >
The problem of synthesis of the given shape contoured directivity pattern of spacecraft hybrid antenna with purpose of uniform "illumination" of the some territorial zone is considered. The ...variational formulation of the synthesis problem according to the given magnitude pattern is used. The mean-square deviation of given and synthesized magnitudes is chosen as optimization criterion. It permits to improve the approximation quality of the magnitudes, to influence by a certain mean on polarized properties of synthesized directivity patterns, and also to satisfy set additional requirements. Examples of synthesis of the contoured directivity patterns, which covers uniform the given territory are presented. In these examples, the hybrid antenna consisting of the rectangular cutting from a parabolic reflector and flat feed array is used.
Broadband quasi-microstrip anisotropic antennas Popovic, Z.B.; Kuester, E.; DeLyser, R. ...
IEEE Antennas and Propagation Society International Symposium 1992 Digest,
1992
Conference Proceeding
In the present work, the authors consider the limiting case of grated patches in the sense that the microstrip dielectric is air and the quasi-microstrip antenna consists of a linear array of narrow ...printed strips (or thin cylindrical wires) that are far apart compared to their width (radius). The efficiency of such an antenna should be the upper limit on the efficiency of a true microstrip version. The predicted impedances, current distributions, efficiencies, and far-field patterns of these antennas, as well as measured patterns on an eleven-element antenna around 2 GHz, are presented.< >
