Extraction of Unloaded Q and Coupling Matrix From Measurements on Filters With Large Losses

Macchiarella, Giuseppe

doi:10.1109/lmwc.2010.2047455

Cited by 55 publications

(62 citation statements)

References 6 publications

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“…However, the accuracy of M SL , as calculated by (4) or (5), is rather poor for a filter diagnosis due to the second order effects of a physical filter. So, the method in [1] and Cauchy methods (as in [2,14]) can not diagnose the filters with S-L coupling.…”

Section: Basic Theorymentioning

confidence: 98%

“…A modified frequency transformation used for converting the measured S-parameters from the bandpass domain f to the normalized lowpass domain s is adopted here as [2] …”

Section: Basic Theorymentioning

confidence: 99%

“…In recent years, the interest has been growing in methods for extracting the CM of microwave filters from measurements (or simulations) including losses, such as a five-parameter optimization method in [1], Cauchy method in [2] and the analytical method in [3]. A sequential tuning method was also reported in [4].…”

Section: Introductionmentioning

confidence: 99%

“…A sequential tuning method was also reported in [4]. However, these methods in [1][2][3][4] have not taken the source-load coupling into account. The methods in [1,2] require assuming all the resonators with the same unloaded Q.…”

Section: Introductionmentioning

confidence: 99%

“…However, these methods in [1][2][3][4] have not taken the source-load coupling into account. The methods in [1,2] require assuming all the resonators with the same unloaded Q. The method in [3] is attractive, because it overcomes the assumption of uniform unloaded Q for each resonator.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Improved Extraction of Coupling Matrix and Unloaded Q From S-Parameters of Lossy Resonator Filters

Wang¹,

Xu²,

Wei³

et al. 2011

PIER

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Abstract-This paper presents a two-stage optimization method for accurately extracting the coupling matrix (CM) and the unloaded quality factor (unloaded Q) of each resonator from the measured (or simulated) S-parameters of lossy cross-coupled resonator bandpass filters. The method can be used in computer-aided tuning (CAT) of microwave filters to accelerate filter design and physical realization. In our method, the Cauchy method is employed for determining characteristic polynomials of the S-parameters in the normalized lowpass frequency domain, and the CM and unloaded Q are extracted by two-stage optimization method using genetic algorithm. With respect to the previous methods available in the literatures, the proposed method allows the CM extraction of the filter with sourceload coupling. Moreover, the accuracy and robustness of the method can be improved due to the usage of the second stage optimization. The proposed method is applied to the diagnosis of a general coupled resonator filter with/without source-load coupling.

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Section: Basic Theorymentioning

confidence: 98%

“…A modified frequency transformation used for converting the measured S-parameters from the bandpass domain f to the normalized lowpass domain s is adopted here as [2] …”

Section: Basic Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Improved Extraction of Coupling Matrix and Unloaded Q From S-Parameters of Lossy Resonator Filters

Wang¹,

Xu²,

Wei³

et al. 2011

PIER

View full text Add to dashboard Cite

show abstract

Computer-aided diagnosis of lossy microwave coupled resonators filters

Wang

2011

Int J RF and Microwave Comp Aid Eng

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A method is presented for extracting the coupling matrix (CM) and the unloaded Q from the measured (or electromagnetic simulated) scattering parameters of a lossy coupled resonators bandpass filter. The method can be used for computer-aided tuning of a microwave filter. The method consists of two elements: 1) a three-parameter optimization method is proposed to obtain the unloaded Q (assuming all the resonators with the same unloaded Q) and to remove the phase shift of the measured S-parameters caused by the phase loading and the transmission lines at the input/output ports of a filter; 2) the Cauchy method is used for determining characteristic polynomial models of the S-parameters of a microwave filter in the normalized low-pass frequency domain. Once the characteristic polynomials of the S-parameters without phase-shift effects are determined, the CM of a filter with a given topology can be extracted using well-established techniques. Three diagnosis examples illustrate the validity of the proposed method.

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Support-vector modeling of electromechanical coupling for microwave filter tuning

Zhou

Duan

Huang

2012

Int J RF and Microwave Comp Aid Eng

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Extraction of Unloaded Q and Coupling Matrix From Measurements on Filters With Large Losses

Cited by 55 publications

References 6 publications

Improved Extraction of Coupling Matrix and Unloaded Q From S-Parameters of Lossy Resonator Filters

Improved Extraction of Coupling Matrix and Unloaded Q From S-Parameters of Lossy Resonator Filters

Computer-aided diagnosis of lossy microwave coupled resonators filters

Support-vector modeling of electromechanical coupling for microwave filter tuning

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