A Direct Preconditioner for Coupling Matrix Reconfiguration of Bandpass Filters With Irregular Couplings Using Continuation Method
- 11 January 2021
- journal article
- research article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Microwave Theory and Techniques
- Vol. 69 (2), 1394-1403
- https://doi.org/10.1109/tmtt.2020.3045991
Abstract
In this article, a direct preconditioner is proposed for coupling matrix reconfiguration of bandpass filters with irregular couplings using the coefficient-parameter continuation method. With the preconditioner, the continuation method can be effectively used for filter synthesis and model extraction of bandpass filters with irregular couplings. In dealing with practical filters that contain a coupling topology with regular cross couplings introduced intentionally or unintentionally, the proposed preconditioner, being used as the start system in the continuation method, can swiftly lead to the solution that matches the physical realization. The preconditioner is physics-based and can be easily obtained by reconfiguring the regular coupling topology with the conventional method. The continuation process with a coefficient-parameter homotopy for coupling matrix reconfiguration is formulated for the first time, which transforms a coupling matrix in the canonical form to that in the desired one with irregular couplings. The convergence of the solution and a bootstrapping approach for dealing with multiple irregular couplings are also discussed. The method provides an enabling tool for robot automatic tuning (RAT) of advanced microwave bandpass filters. Three practical examples are presented, including one synthesis example and two model extraction examples for RAT, demonstrating the effectiveness of the reconfiguration method for practical applications.Keywords
Funding Information
- Research Grants Council of the Hong Kong SAR, China (14208920)
- Hong Kong Ph.D. Fellowship
This publication has 16 references indexed in Scilit:
- Model-Based Vector-Fitting Method for Circuit Model Extraction of Coupled-Resonator DiplexersIEEE Transactions on Microwave Theory and Techniques, 2016
- Coupling Matrix Extraction and Reconfiguration Using a Generalized Isospectral Flow MethodIEEE Transactions on Microwave Theory and Techniques, 2015
- Synthesis of Resonator Filters With Arbitrary Topology Using Hybrid MethodIEEE Transactions on Microwave Theory and Techniques, 2007
- Exhaustive approach to the coupling matrix synthesis problem and application to the design of high degree asymmetric filtersInternational Journal of RF and Microwave Computer-Aided Engineering, 2007
- Synthesis of general topology multiple coupled resonator filters by optimizationPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Optimum network topologies for high power microwave filtersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Synthesis of cross-coupled resonator filters using an analytical gradient-based optimization techniqueIEEE Transactions on Microwave Theory and Techniques, 2000
- General coupling matrix synthesis methods for Chebyshev filtering functionsIEEE Transactions on Microwave Theory and Techniques, 1999
- On the maximum number of finite transmission zeros of coupled resonator filters with a given topologyIEEE Microwave and Guided Wave Letters, 1999
- Coefficient-parameter polynomial continuationApplied Mathematics and Computation, 1989