Krylov's Solver Based Technique for the Cascade Connection of Multiple $N$-Port Multimodal Scattering Matrices

IET Microwaves, Antennas & Propagation

Esteban³

et al. 2016

Institution of Engineering and Technology (IET)Martínez-Zamora, JÁ.; Belenguer, Á.; Esteban González, H.; Boria Esbert, VE. (2016 AbstractIn this paper a new segmentation strategy is presented for the full-wave analysis of directly coupled cavity filters in substrate integrated waveguide technology. The whole SIW filter is enclosed inside an external fictitious rectangular waveguide, which does not affect the propagation inside the SIW assuming that the SIW is well designed and there is not significant power leakage. The external rectangular waveguide allows to easily segment the structure into building blocks that are composed of circular metallic vias inside a rectangular waveguide. The GSM of these building blocks are obtained with highly efficient techniques specifically suited for the analysis of H-plane rectangular waveguided devices. Some building blocks are repeated along the structure, and their scattering matrix has to be computed only once, thus improving the numerical efficiency. The scattering matrices of all the building blocks are cascaded using an appropriate method, and the scattering matrix of the whole SIW filter is finally obtained.In order to test the efficiency of this new method, a SIW filter of 8 coupled cavities with a bandpass response centred at 11 GHz is analysed. Results from this analysis show that the computational time has been significantly reduced when compared with other specific SIW analysis methods or with commercial general purpose software, while maintaining a good accuracy.

Section: Introductionmentioning

confidence: 99%

Segmentation strategy for the efficient analysis and design of substrate integrated waveguide directly coupled cavity filters

Martínez

IET Microwaves, Antennas & Propagation

Esteban³

et al. 2016

“…Recently, in [7], a very efficient strategy to connect multiport devices has been proposed. This strategy, which is based on an iterative Krylov's solver, is able to provide, not only the response of the cascaded network at the free ports, but also the modal weights at the internal ports.…”

Section: Introductionmentioning

confidence: 99%

“…In [7], however, only one of the symmetries of a rectangular waveguide was considered (the symmetry of a rectangular waveguide is double). Besides, the partial correction of [7] was applied to the Krylov's-based technique, and not to the traditional cascading expressions. Therefore in this paper, a rigorous study of possible modal mismatches at the connected ports is presented, and a systematic criterion to define the polarity of the modes (or the reference systems of the ports) is proposed for general lines or waveguides with a single or double transversal symmetry.…”

Section: Introductionmentioning

confidence: 99%

Systematic procedure to avoid unintended polarity mismatch in the cascade connection of multiport devices with symmetric feeding lines

IET Microwaves, Antennas & Propagation

Borja

Caballero³

et al. 2015

Abstract:The traditional cascading Q2 of generalised scattering matrices (GSMs) approach assumes that the modal sets at the connected ports of a cascaded network are strictly equal. This implies a careful selection of the modal polarities (numerical port solution), or the reference systems (analytical port solution), of every port to be connected. Usually, the connection scheme of every device is known a priori, during the solving stage. Then, the individual GSMs are preprocessed, or auxiliary devices intended to correct possible modal mismatches at the ports are included in appropriate positions among the cascade, so that the traditional cascading-by-pairs approach can be directly applied. This scheme clearly complicates the reutilisation of previously calculated GSMs, and mixes the cascading with the solution of the individual building blocks. In this study, a systematic procedure is proposed to define the polarity of the modes at the ports of a multiport device fed with transmission lines or waveguides showing a single or double symmetry. The modified expressions to calculate the scattering parameters of the cascade of two multiport devices, incorporating the appropriate regular modal corrections to apply when this criterion is used to define the modal polarity at the ports, is also presented in this study. This strategy is more convenient from the point of view of programming, less error-prone and easier to implement.

“…Therefore, an iterative Krylov's based technique was proposed in [3]. For an arbitrary external excitation, that technique was able to provide the modal weights, not only at the free ports, but also at the connected ones.…”

Section: Introductionmentioning

confidence: 99%

“…This eGSM will return the emergent modal weights at the free and connected ports for any arbitrary incidence at the free ports. This approach is more intuitive and easier to implement than the one in [3], providing with faster results when calculating the whole multimodal response of the connected network.…”

Section: Introductionmentioning

confidence: 99%

Extending the Cascading by Pairs of Multiport Generalized Scattering Matrices for Characterizing the Connected Ports

Caballero

IEEE Microw. Wireless Compon. Lett.

Esteban

et al. 2014

Abstract-An extension to the traditional technique for cascading generalized scattering matrices (GSMs) by pairs is presented. It can solve the connection of an arbitrary number of networks, with an arbitrary number of ports, while being quite intuitive and easy to implement. It is able to compute, not only the response at the free ports of the global network -like the traditional cascading-by-pairs does-, but also the connected ports, obtaining an extended GSM (eGSM), which can be used to find the field inside the full network for an arbitrary incidence.