Impedance Matrix Interpolation Research Articles

Improved MoM-PO-Based Technique for Wideband Analysis of Antennas around Large Platforms

An improved wide-band analysis which combines the hybrid method of moments-physical optics (MoM-PO) formula with impedance matrix interpolation technique for antennas around large platforms is presented. The algorithm proposed in this paper interpolated the mutual impedance matrix between MoM and PO regions rather than the MoM self-matrix. This practice can result in more accurate frequency response than the conventional approach. Sample numerical results demonstrate the capability of the algorithm.

FAST ANALYSIS OF MICROSTRIP ANTENNAS OVER A FREQUENCY BAND USING AN ACCURATE MOM MATRIX INTERPOLATION TECHNIQUE

A novel method based on the hybrid volume-surface integral equation (VSIE) and the impedance matrix interpolation technique is presented for the fast analysis of microstrip antennas in frequency sweeps. A novel impedance matrix interpolation scheme is extended to the impedance matrix associated with VSIE, thus providing high accuracy, high e-ciency, and large interpolation bandwidth for metal-dielectric composite problems. To demonstrate the efiectiveness and accuracy of the proposed technique, numerical results for typical rectangular patch antennas and a broadband U-slot rectangular patch antenna are presented. Good agreement among the interpolation results, the exact method of moments (MoM) solutions, the flnite element method (FEM) solutions, and measured data is observed over the bandwidth. The interpolation bandwidth is further investigated through a scattering problem. Numerical results show that high accuracy is obtainable within 10 : 1 bandwidth.

An Accurate Interpolation Scheme With Derivative Term for Generating MoM Matrices in Frequency Sweeps

A new accurate impedance matrix interpolation algorithm is proposed for frequency sweeps arising in the method of moments (MoM). Its performance is optimized by specifying the choice of the internal frequency sample within a given frequency band. The modified matrix element employed in this scheme is a product of the normalized frequency and the remaining part of the impedance matrix element after factoring out the dominant phase term, where the normalized frequency means that the frequency is normalized by the highest frequency. Based on the modified matrices at three normalized frequency samples and the derivative of the modified matrix at the internal sample, the matrices over the frequency band are fast generated via interpolation. The proposed scheme requires the same storage as the Hermite scheme and 25% storage more than the improved Lagrange scheme. Numerical examples indicate that it yields more accurate matrices over the frequency band than both the Hermite scheme and the improved Lagrange scheme.

Fast MM-PO-based numerical modelling technique for wideband analysis of antennas near conducting objects

A highly efficient computational electromagnetics technique based upon method of moments-physical optics (MM-PO) hybrid formulation combined with the impedance matrix interpolation and a dynamic adaptive frequency sampling for wideband analysis of antennas radiating in the presence of conducting bodies is presented. Sample numerical results demonstrate the capability of the technique.

A fast wideband analysis of radiation and scattering problems by impedance‐matrix interpolation combined with progressive numerical method

AbstractIt has been shown that impedance‐matrix interpolation is a very direct and effective technique to speed up the wide‐band analysis of radiation and scattering problems. In view of the time‐costing problem of solving the large impedance matrix using impedance‐matrix interpolation and the good performance of the progressive numerical method (PNM) for dealing with large electromagnetic problems, a fast and effective wideband analysis of radiation and scattering problems by impedance‐matrix interpolation combined with a progressive numerical method is presented in this paper. Some numerical results are given to illustrate the effectiveness and the accuracy of the proposed method. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 56–59, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20374

Wide-band emc analysis of on-platform antennas using impedance-matrix interpolation with the moment method-physical optics method

An efficient method for the broadband EMC analysis of on-platform antennas is proposed, where the hybrid moment method-physical optics (MM-PO) formula is employed to generate the impedance matrix. The impedance matrix is calculated at relatively large frequency intervals and interpolated to approximate its values at intermediate frequencies. Numerical examples, including the coupling and radiation pattern evaluation of on-platform antennas, are presented. Through these examples, it is shown that the proposed method can greatly reduce the computing time in the wide-band computation compared with the traditional MM-PO method.

An algorithm for interpolating the frequency variations of method-of-moments matrices arising in the analysis of planar microstrip structures

This paper presents a new impedance matrix interpolation algorithm, in the context of method of moments, for planar microstrip structures. Three different interpolating functions are implemented depending upon the distance between the basis and testing functions. To demonstrate its efficiency, the technique is applied to several planar microstrip structures, viz. a patch antenna fed by microstrip line and a 4/spl times/4 planar patch array. It is demonstrated that the use of the proposed impedance matrix interpolation scheme can result in significant savings in the computation time with little or no compromise in the accuracy of the solution.

Efficient analysis of microwave structures using a matrix interpolation method

AbstractThis paper presents a new impedance matrix interpolation algorithm, in the context of method of moments (MoM), for planar microstrip structures. Three different interpolating functions are implemented, depending upon the distance between the locations of the basis and the testing functions. The accuracy and computation times for the direct MoM and the impedance matrix interpolation methods are compared for several planar microstrip structures. It is demonstrated that the use of the proposed impedance matrix interpolation scheme can result in significant savings in the computation time with little or no compromise in the accuracy of the solution. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 439–447, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10785