Efficient evaluation of spatial-domain MoM matrix entries in the analysis of planar stratified geometries

An efficient hybrid method for evaluation of spatial-domain method-of-moments (MoM) matrix entries is presented in this paper. It has already been demonstrated that the introduction of the closed-form Green's functions into the MoM formulation results in a significant computational improvement in filling up MoM matrices and, consequently, in the analysis of planar geometries. To achieve further improvement in the computational efficiency of the MoM matrix entries, a hybrid method is proposed in this paper and, through some examples, it is demonstrated that it provides significant acceleration in filling up MoM matrices while preserving the accuracy of the results

Comparative study of acceleration techniques for integrals and series in electromagnetic problems

Most of the electromagnetic problems can be reduced down to either integrating oscillatory integrals or summing up complex series. However, limits of the integrals and the series usually extend to infinity. In addition, they may be slowly convergent. Therefore, numerically efficient techniques for evaluating the integrals or for calculating the sum of infinite series have to be used to make the numerical solution feasible and attractive. In the literature, there are a wide range of applications of such methods to various EM problems. In this paper, our main aim is to critically examine the popular series transformation (acceleration) methods which are used in electromagnetic problems and compare them by numerical examples

Efficient and accurate EM simulation technique for analysis and design of MMICs

A numerically efficient technique for the analysis and design of MMIC circuits is introduced and applied to some realistic problems. The formulation is based on the method of moments (MoM) in the spatial domain, and utilizes closed-form Green's functions. Incorporating the closed-form Green's functions into the MoM has resulted in an efficient and accurate CAD algorithm. This is because use of the closed-form Green's functions not only eliminates the calculation of the spatial-domain Green's functions, but also makes it possible to evaluate the MoM matrix elements analytically We have demonstrated the application of this method here for some stripline and microstrip geometries, and compared the results with those obtained from commercial EM software, em (Sonnet Software, Inc.) © 1997 John Wiley & Sons, Inc

On the evaluation of spatial domain MoM matrix entries containing closed form Green's functions

A microstrip patch antenna is analyzed to demonstrate the efficiency and accuracy of the hybrid technique for the evaluation of the Method of Moments (MoM) reaction integrals containing closed form Green's functions. The proposed hybrid method can reduce the matrix fill-time significantly, without sacrificing the accuracy, with an appropriate choice for ρls. The proper choice of ρls depends upon the Green's function, as well as on the cell size used for discretization, and that the choice of ρmax should be carried out in accordance with the magnitude of the Green's function at ρmax

Analysis of Finite Microstrip Structures Using an Efficient Implementation of the Integral Equation Technique

An efficient numerical implementation of the Integral Equation technique (IE) has been developed for the analysis of the electrical characteristics of finite microstrip structures. The technique formulates a volume version of the IE for the finite dielectric objects, and a standard surface IE technique for the metallic areas. The system of integral equations formu- lated are solved with special numerical techniques described in this paper. The input impedances of several microstrip antennas have been computed, showing good agreement with respect mea- surements. The technique has shown to be accurate even for complex geometries containing several stacked dielectric layers. The radiation patterns of the structures have also been com- puted, and measured results from real manufactured hardware confirm that backside radiation and secondary lobes are accurately predicted by the theoretical model. The paper also discuss a suitable excitation model for finite size ground planes, and investigates the possibilities for an independent meshing of the metallic areas and the dielectric objects inside a given geom- etry. The practical value of the approach derived is that microstrip circuits can be designed minimizing the volume and size of the dielectric substrates.This work has been supported bythe Spanish National Project ESP2001-4546-PE, and RegionalSeneca Project PB/4/FS/02

Comparative study of acceleration techniques for integrals and series in electromagnetic problems

Most electromagnetic problems can be reduced to either integrating oscillatory integrals or summing up complex series. However, limits of the integrals and the series usually extend to infinity, and, in addition, they may be slowly convergent. Therefore numerically efficient techniques for evaluating the integrals or for calculating the sum of an infinite series have to be used to make the numerical solution feasible and attractive. In the literature there are a wide range of applications of such methods to various EM problems. In this paper our main aim is to critically examine the popular series transformation (acceleration) methods which are used in electromagnetic problems and to introduce a new acceleration technique for integrals involving Bessel functions and sinusoidal functions

Numerically efficient analysis of slot-lines in multilayer media using closed form Green's functions

A numerically efficient technique for the analysis of slot-line geometries in multilayer media is presented using closed-form Green's functions in the spatial domain employed in conjunction with the Method of Moments (MoM). The computed equivalent magnetic current distribution on the slot is used to determine the power radiated by the slot and the input impedance. In power calculations, the spatial domain Green's functions are approximated as a power series of radial distance, and the integrals involving the Green's functions are carried out analytically saving considerable amount of computation time

Waveguide bandpass filters for MMIC applications

Novel 3D multilayer waveguide structures for MMIC filter applications are proposed and examined in this paper. Periodic multilayer-waveguide resonant structures, which can be used for bandpass filters, are presented. The structure has a high Q and supports a simple fabrication process. An MMIC filter based on this proposed periodic-resonator configuration is designed at 74 GHz using the commercial software package HFSS. The simulated S-parameter responses and a photomicrograph of the fabricated monolithic dielectric filled rectangular waveguide on GaAs substrate are presented

Periodic Green's function for skewed 3-D lattices using the Ewald transformation

We apply the Ewald acceleration technique to the efficient evaluation of periodic Green's functions (GFs) for 3-D skewed lattices like those arising in electromagnetic/photonic band-gap (EBG/PBG) structures and metamaterials (MTMs). We develop the expression for the optimal value of an associated splitting parameter, derive the gradient of the scalar potential GFs and address the extraction of singularity for both vector/scalar potential GF and their curl/gradient. Several numerical implementation issues are also discussed leading to further enhancement in computational speed, accuracy, and numerical stability. Finally, the accuracy of the developed GFs is verified against well established algorithms. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1353-1357, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.2242