Computational electromagnetics

About: Computational electromagnetics is a research topic. Over the lifetime, 6412 publications have been published within this topic receiving 113727 citations. The topic is also known as: Electromagnetic field analysis.

A new approach to FET model scaling and MMIC design based on electromagnetic analysis

Abstract: A new approach, using electromagnetic analysis, is proposed for field-effect transistor model scaling and monolithic-microwave integrated-circuit (MMIC) design. It is based on an empirical distributed modeling technique where the active device is described in terms of an external passive structure connected to a suitable number of internal active sections. On this basis, an equivalent admittance matrix per gate unit width is obtained which, as confirmed by experimental results provided in this paper, is consistent with simple scaling rules. The same technique can also be adopted for a "global approach" to MMIC design where complex electromagnetic phenomena are also taken into account. An example of application concerning this aspect is presented.

Theoretical Study on the Rank of Integral Operators for Broadband Electromagnetic Modeling From Static to Electrodynamic Frequencies

Abstract: To facilitate the broadband modeling of integrated electronic and photonic systems from static to electrodynamic frequencies, we propose an analytical approach to study the rank of the integral operator for electromagnetic analysis, which is valid for an arbitrarily shaped object with an arbitrary electric size. With this analytical approach, we theoretically prove that for a prescribed error bound, the minimal rank of the interaction between two separated geometry blocks in an integral operator, asymptotically, is a constant for 1-D distributions of source and observation points, grows very slowly with electric size as square root of the logarithm for 2-D distributions, and scales linearly with the electric size of the block diameter for 3-D distributions. We thus prove the existence of an error-bounded low-rank representation of both surface- and volume-based integral operators for electromagnetic analysis, irrespective of electric size and object shape. Numerical experiments validated the proposed analytical approach and the resultant findings on the rank of integral operators. This paper provides a theoretical basis for employing and further developing low-rank matrix algebra for accelerating the integral-equation-based electromagnetic analysis from static to electrodynamic frequencies.

Use of polarization in electromagnetic inverse scattering

Abstract: The complete description of electromagnetic scattering processes implies polarization and since an electromagnetic scatterer acts like a polarization transformer we require measurements for the complete description of the target scattering matrices so that the descriptive parameters of a scatterer can be uniquely recovered from the measured field data. For the purpose of introducing the concept of polarization utilization in practice, the radar case is chosen and generalizations to other electromagnetic inverse problems are presented in the conclusions. For example, in radar target discrimination, identification and imaging use of measurement data available over the entire spatial frequency domain of the radar cross section must be made leading to various approximate frequency domain related approaches. Mainly for historical reasons of having had amplitude data available only, in most cases the approximations had been simplified to purely scalar nature; i.e., polarization-dependent properties were discarded, and the resulting theories are no longer valid or unique. It is the main objective of this analysis to show that because of the vector nature of electromagnetic inverse scattering, theories, if applicable in practice, require incorporation of complete polarization information into their formulation. By applying this approach to existing theories, it is shown that remarkable improvements in fidelity and quality of the reconstructed images are obtained and that indeed there is ample justification for continuing efforts in developing methods and theories of inverse scattering applicable to all those fields of physical sciences where information on the characteristic parameters of a scattering process is to be drawn from remote measurements, be it the electromagnetic vector case or the even more complicated seismic case of s and p wave interactions in elastic media.

Efficient electromagnetic near-field computation by the multilevel fast multipole method employing mixed near-field/far-field translations

Abstract: Method of moments (MoM) solutions of electromagnetic surface integral equations provide the desired amplitudes of the equivalent surface currents on the Huygens' surfaces around the involved objects, where the solution process is nowadays routinely accelerated by fast integral methods such as the multilevel fast multipole method (MLFMM). Computation of radiated or scattered electromagnetic fields produced by these currents requires integration over the Huygens' surfaces and can easily become extremely time-consuming for large numbers of observation points. In this contribution, integration of electromagnetic near-fields is accelerated by a postprocessing MLFMM approach, where near-field and far-field translations are combined in order to achieve optimum performance. The proposed approach has been applied in the postprocessing stage of a finite element boundary integral (FEBI) method with fast integral equation solution by MLFMM, saving a large amount of postprocessing computation time. The formulation of the proposed acceleration is presented and numerical results are shown.