Port Parameter Extraction-Based Self-Consistent Coupled EM-Circuit FEM Solvers

• Published in: IEEE transactions on components, packaging, and manufacturing technology (2011) packaging, and manufacturing technology (2011), 2022-06, Vol.12 (6), p.1040-1048
• Main Authors: Ramachandran, Omkar H., O'Connor, Scott, Crawford, Zane D., Kempel, Leo C., Shanker, B.
• Format: Article
• Language: English
• Subjects: Circuit simulation; Couplings; Electromagnetics; Engineering; Finite element analysis; Finite element method; finite element methods; Impulse response; Integral equations; Integrated circuit modeling; Linear circuits; Materials Science; Mathematical models; nonlinear circuits; Nonlinear systems; Parameters; semiconductor device modeling; Solvers; Time domain analysis; Transient analysis
• ISSN: 2156-3950; 2156-3985
• DOI: 10.1109/TCPMT.2022.3173487

Self-consistent solution to electromagnetic (EM)-circuit systems is of significant interest for a number of applications. This has resulted in exhaustive research on means to couple them. In time domain, this typically involves a tight integration (or coupling) with field and non-linear circuit solvers. This is in stark contrast to coupled analysis of linear/weakly non-linear circuits and EM systems in frequency domain. Here, one typically extracts equivalent port parameters that are then fed into the circuit solver. Such an approach has several advantages: 1) the number of ports is typically smaller than the number of degrees of freedom, resulting in cost savings; 2) is circuit agnostic; and 3) can be integrated with a variety of device models. Port extraction is tantamount to obtaining impulse response of the linear EM system. In time domain, the deconvolution required to effect this is unstable. Recently, a novel approach was developed for time domain integral equations (TDIEs) to overcome this bottleneck. We extend this approach to time domain finite element method, and demonstrate its utility via a number of examples; significantly, we demonstrate that self-consistent solutions obtained using either a fully coupled or port extraction is identical to the desired precision for non-linear circuit systems. This is shown within a nodal network. We also demonstrate integration of port extracted data directly with drift diffusion equation to model device physics.