Microwave filter analysis using a new 3-D finite-element modal frequency method

In this paper, a reduced basis approximation-based model order reduction for fast and reliable frequency sweep in the time-harmonic Maxwell's equations is detailed. Contrary to what one may expect by observing the frequency response of different microwave circuits, the electromagnetic field within these devices does not drastically vary as frequency changes in a band of interest. Thus, instead of using computationally inefficient, large dimension, numerical approximations such as finite element or boundary element methods for each frequency in the band, the point in here is to approximate the dynamics of the electromagnetic field itself as frequency changes. A much lower dimension, reduced basis approximation sorts this problem out. Not only rapid frequency evaluation of the reduced order model is carried out within this approach, but also special emphasis is placed on a fast determination of the error measure for each frequency in the band of interest. This certifies the accurate response of the reduced order model. The same scheme allows us, in an offline stage, to adaptively select the basis functions in the reduced basis approximation and automatically select the model order reduction process whenever a preestablished accuracy is required throughout the band of interest. Finally, real-life applications will illustrate the capabilities of this approach.

show abstract

“…Thus, (3.10) results in a better conditioned system of equations. This prevents from numerical stagnation 8 …”

Section: Offline-online Decompositionmentioning

confidence: 99%

“…7. This filter was considered in [8], where all dimensions and materials can be found, and was designed to perform a bandstop from 5 to 6.8 GHz. This time we take into account the Frequency (GHz) …”

Section: Cylindrical Dieletric Resonator Filtermentioning

confidence: 99%

Reliable Fast Frequency Sweep for Microwave Devices via the Reduced-Basis Method

Rubia

Razafison

Maday

2009

IEEE Trans. Microwave Theory Techn.

View full text Add to dashboard Cite

show abstract

“…(c) Return loss calculated by the present method (solid line) compared with reported measurements (crosses) (Rubio, Arroyo, & Zapata, 1999). (Brauer, & Lizalek, 1997). (a) Filter structure.…”

Section: Resultsmentioning

confidence: 96%

“…In Figure 12, the results for the LANGER dielectric resonator filter are presented for which measured reference values are available (Brauer & Lizalek, 1997).…”

Section: Resultsmentioning

confidence: 99%

Advanced FD-TD Techniques for the CAD of 3D Microwave Components

Arndt

Ritter

2003

Electromagnetics

View full text Add to dashboard Cite

Advanced techniques for the finite difference time domain (FD-TD) method are described, which improve the efficiency of the simulation of three-dimensional (3D) microwave components, including structures of more general shape. The formulations are based on a combination of a direct subgrid technique with a locally conformal FD-TD algorithm for arbitrarily shaped perfect conductors, and with a modified intersection approach for arbitrary dielectric boundaries. The involved subgrid technique, where a main grid is directly orthogonalized against a dual grid, avoids the usual necessity of additional interpolation terms. Application of the matrix pencil method reduces the number of required time steps. Advantages of the combined techniques are high accuracy, flexibility, and efficiency concerning both storage capacity and CPU time. Their versatility for the CAD of 3D microwave structures is demonstrated with typical examples, like coax feed with dielectric coating, dielectric resonator filter, and waffle-iron filter with round teeth. The accuracy is verified by available measurements or reference calculations.

show abstract

“…That the evaluation of the ROM is slightly slower for the Z formulation than the combined approach is atypical and can be contributed to the very small ROM dimension and to the additional Z-to-S matrix conversion required by the Z formulation. Figure 8 presents a bandpass filter (Brauer & Lizalek, 1997). The structure is fed by coaxial cables.…”

Section: Rectangular Waveguidementioning

confidence: 99%

Efficient Fast Frequency Sweep Without Nonphysical Resonances

Farle¹,

Lösch²,

Dyczij‐Edlinger³

2010

Electromagnetics

View full text Add to dashboard Cite

Single-point methods of moment-matching type provide a most effective means for realizing fast frequency sweeps. The impedance formulation of the finite element method is very well-suited for such techniques, but it is susceptible to interior resonances, especially in the case of lossless microwave structures. This deficiency can be resolved by imposing transparent boundary conditions at the waveguide ports, but the resulting matrices exhibit nonpolynomial frequency-dependency unless all waveguide modes are of the transverse electric and magnetic type. In consequence, single-point methods cannot be applied without approximations. This article proposes a fast frequency sweep technique that handles not only transverse electric and magnetic modes but also transverse electric and transverse magnetic modes without any approximations. Moreover, it retains the efficiency of the impedance formulation but prevents interior resonances from occurring. The theoretical background of and numerical evidence for the failure of the impedance formulation is given, and a mathematical proof for the validity of the new method is presented. Computational results demonstrate the reliability and low error of the suggested approach.

show abstract

Microwave filter analysis using a new 3-D finite-element modal frequency method

Cited by 41 publications

References 10 publications

Reliable Fast Frequency Sweep for Microwave Devices via the Reduced-Basis Method

Reliable Fast Frequency Sweep for Microwave Devices via the Reduced-Basis Method

Advanced FD-TD Techniques for the CAD of 3D Microwave Components

Efficient Fast Frequency Sweep Without Nonphysical Resonances

Contact Info

Product

Resources

About