This article deals with several improvements of the spectral domain analysis of microstrip and co... more This article deals with several improvements of the spectral domain analysis of microstrip and coplanar circuits. Thus different kinds of expansion functions allow nonuniform meshing strategies with an improved current description. Furthermore a combination of acceleration methods with respect to the evaluation of the spectral domain integrals and special matrix fill techniques leads to a drastic reduction of the computational
This paper reviews transmission anomalies of freestanding frequency surfaces (FSS), which are com... more This paper reviews transmission anomalies of freestanding frequency surfaces (FSS), which are commonly used as filter and guiding structures in the far IR region. The effect is characterized by a sharp breakdown of the transmission factor in the passband and was first revealed by measurements. The paper demonstrates the numerical confirmation of these effects by computer aided calculations based on
This paper deals with the electrodynamic analysis of coplanar (M)MIC and submm-wave structures ba... more This paper deals with the electrodynamic analysis of coplanar (M)MIC and submm-wave structures based on a surface/volume integral equation method. The slot areas and additional 3-D components are modeled by magnetic and electric surface currents and polarization volume currents. High accuracy and efficiency is achieved by applying complete analytical solutions for the asymptotic system matrix combined with adaptive database strategies
... null Bangert, Axel / B??ck, Georg / Bose, Ranjan / Detlefsen, J??rgen / Djordjevic, Ivan B. /... more ... null Bangert, Axel / B??ck, Georg / Bose, Ranjan / Detlefsen, J??rgen / Djordjevic, Ivan B. / Follmann, R??diger / Fuchs, G??nter / Gaspard, Ingo / Gevorgian, Spartak / Hartnagel, Hans / Hofmann, Klaus / Jondral, Friedrich / Kasper, Erich / Kastell, Kira / Klein, Anja / Kn??chel, Reinhard ...
Using integral equation methods for the analysis of complex (M)MIC structures, the computation an... more Using integral equation methods for the analysis of complex (M)MIC structures, the computation and storage effort for the solution of the linear systems of equations with their fully populated matrices still forms the main bottleneck. In the last years, remarkable improvements could be achieved by means of diakoptic methods and related preconditiners. In this contribution, we present a method based on the optimized decomposition of the system matrix depending on the circuit topology. The system matrix is splitted in a densely populated matrix and a mainly blockdiagonal matrix with overlapping submatrices. The latter matrix is used for the generation of high performance preconditioners within Krylov subspace methods using sparsified matrix storage methods, adaptive Cholesky decompositions and optimized forward/backward substitutions. Furthermore, we present an integration technique using a complete analytical treatment for the strongly oscillating parts of the spectral domain integra...
This contribution deals with a spectral domain analysis of planar circuits with a very flexible n... more This contribution deals with a spectral domain analysis of planar circuits with a very flexible nonuniform mesh strategy using different kinds of expansion functions. Accelerating schemes to improve the evaluation of the spectral domain integrals and special matrix fill techniques are presented
For the analysis and design process of (M)MIC structures, electromagnetic simulators based on the... more For the analysis and design process of (M)MIC structures, electromagnetic simulators based on the method of moments (MoM) are widely used due to their high accuracy and good modeling capabilities. For the standard MoM using an explicit system matrix, many improvements could be achieved for a faster and more accurate computation of the matrix entries. The solution of the linear systems of equations typically remains the most cumbersome part of the MoM. An important class of methods to improve the solution process was initialized by the diacoptic theory of linear antennas. This theory is based on a component decomposition and is therefore not restricted to the analysis of wire antennas but is particularly well suited for (M)MIC structures with its typical circuit component subdivision. Diacoptic strategies are mainly based on the use of so-called macro basis functions (MBs). leading to multilevel MoM implementations. In our contribution, we first compare different versions of the two-...
IEEE Transactions on Microwave Theory and Techniques, 1999
This paper deals with the electrodynamic analysis of structures embedded in multilayered media, w... more This paper deals with the electrodynamic analysis of structures embedded in multilayered media, which consist of both microstrip/stripline and coplanar/slotline components also comprising three-dimensional components like vertical interconnects, finite dielectric fillings, or coatings. The analysis is based on a surface/volume integral-equation method using a magnetic surface current description for the slot areas, electric surface currents for the planar microstrip/stripline structures,
IEEE Transactions on Antennas and Propagation, 2000
For accurate scattering computations in the far-field of flat finite objects, field based ray opt... more For accurate scattering computations in the far-field of flat finite objects, field based ray optical methods cannot be used directly, since the finiteness of the objects is not considered in the formulations. In this paper, planar near-field scanning techniques are used to overcome this problem. In particular, scattered ray optical fields are first computed in a scanning plane in the
IEEE Transactions on Antennas and Propagation, 2006
... The resulting near-field images can be used to extract the far-field radar cross section (RCS... more ... The resulting near-field images can be used to extract the far-field radar cross section (RCS) of the target overcoming the need for long-range measurement setups. ... Index TermsNear-field measurements, radar cross section (RCS) , radar imaging. ...
This article deals with several improvements of the spectral domain analysis of microstrip and co... more This article deals with several improvements of the spectral domain analysis of microstrip and coplanar circuits. Thus different kinds of expansion functions allow nonuniform meshing strategies with an improved current description. Furthermore a combination of acceleration methods with respect to the evaluation of the spectral domain integrals and special matrix fill techniques leads to a drastic reduction of the computational
This paper reviews transmission anomalies of freestanding frequency surfaces (FSS), which are com... more This paper reviews transmission anomalies of freestanding frequency surfaces (FSS), which are commonly used as filter and guiding structures in the far IR region. The effect is characterized by a sharp breakdown of the transmission factor in the passband and was first revealed by measurements. The paper demonstrates the numerical confirmation of these effects by computer aided calculations based on
This paper deals with the electrodynamic analysis of coplanar (M)MIC and submm-wave structures ba... more This paper deals with the electrodynamic analysis of coplanar (M)MIC and submm-wave structures based on a surface/volume integral equation method. The slot areas and additional 3-D components are modeled by magnetic and electric surface currents and polarization volume currents. High accuracy and efficiency is achieved by applying complete analytical solutions for the asymptotic system matrix combined with adaptive database strategies
... null Bangert, Axel / B??ck, Georg / Bose, Ranjan / Detlefsen, J??rgen / Djordjevic, Ivan B. /... more ... null Bangert, Axel / B??ck, Georg / Bose, Ranjan / Detlefsen, J??rgen / Djordjevic, Ivan B. / Follmann, R??diger / Fuchs, G??nter / Gaspard, Ingo / Gevorgian, Spartak / Hartnagel, Hans / Hofmann, Klaus / Jondral, Friedrich / Kasper, Erich / Kastell, Kira / Klein, Anja / Kn??chel, Reinhard ...
Using integral equation methods for the analysis of complex (M)MIC structures, the computation an... more Using integral equation methods for the analysis of complex (M)MIC structures, the computation and storage effort for the solution of the linear systems of equations with their fully populated matrices still forms the main bottleneck. In the last years, remarkable improvements could be achieved by means of diakoptic methods and related preconditiners. In this contribution, we present a method based on the optimized decomposition of the system matrix depending on the circuit topology. The system matrix is splitted in a densely populated matrix and a mainly blockdiagonal matrix with overlapping submatrices. The latter matrix is used for the generation of high performance preconditioners within Krylov subspace methods using sparsified matrix storage methods, adaptive Cholesky decompositions and optimized forward/backward substitutions. Furthermore, we present an integration technique using a complete analytical treatment for the strongly oscillating parts of the spectral domain integra...
This contribution deals with a spectral domain analysis of planar circuits with a very flexible n... more This contribution deals with a spectral domain analysis of planar circuits with a very flexible nonuniform mesh strategy using different kinds of expansion functions. Accelerating schemes to improve the evaluation of the spectral domain integrals and special matrix fill techniques are presented
For the analysis and design process of (M)MIC structures, electromagnetic simulators based on the... more For the analysis and design process of (M)MIC structures, electromagnetic simulators based on the method of moments (MoM) are widely used due to their high accuracy and good modeling capabilities. For the standard MoM using an explicit system matrix, many improvements could be achieved for a faster and more accurate computation of the matrix entries. The solution of the linear systems of equations typically remains the most cumbersome part of the MoM. An important class of methods to improve the solution process was initialized by the diacoptic theory of linear antennas. This theory is based on a component decomposition and is therefore not restricted to the analysis of wire antennas but is particularly well suited for (M)MIC structures with its typical circuit component subdivision. Diacoptic strategies are mainly based on the use of so-called macro basis functions (MBs). leading to multilevel MoM implementations. In our contribution, we first compare different versions of the two-...
IEEE Transactions on Microwave Theory and Techniques, 1999
This paper deals with the electrodynamic analysis of structures embedded in multilayered media, w... more This paper deals with the electrodynamic analysis of structures embedded in multilayered media, which consist of both microstrip/stripline and coplanar/slotline components also comprising three-dimensional components like vertical interconnects, finite dielectric fillings, or coatings. The analysis is based on a surface/volume integral-equation method using a magnetic surface current description for the slot areas, electric surface currents for the planar microstrip/stripline structures,
IEEE Transactions on Antennas and Propagation, 2000
For accurate scattering computations in the far-field of flat finite objects, field based ray opt... more For accurate scattering computations in the far-field of flat finite objects, field based ray optical methods cannot be used directly, since the finiteness of the objects is not considered in the formulations. In this paper, planar near-field scanning techniques are used to overcome this problem. In particular, scattered ray optical fields are first computed in a scanning plane in the
IEEE Transactions on Antennas and Propagation, 2006
... The resulting near-field images can be used to extract the far-field radar cross section (RCS... more ... The resulting near-field images can be used to extract the far-field radar cross section (RCS) of the target overcoming the need for long-range measurement setups. ... Index TermsNear-field measurements, radar cross section (RCS) , radar imaging. ...
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