Andrew Charest

Compact Macromodeling of High-Speed Circuits via Delayed Rational Functions

This letter introduces a new method for compact macromodeling of high-speed circuits with long delays, characterized by tabulated time-domain data. The algorithm is based on partitioning the response and subsequently approximating each partition with a low-order sum-of-exponentials, delayed in time-domain. This results in a compact low-order macromodel in the form of delayed-differential equations, which can be efficiently analyzed using SPICE like simulators.

Time Domain Delay Extraction-Based Macromodeling Algorithm for Long-Delay Networks

This paper introduces a new time-domain approach for compact macromodeling of multiport high-speed circuits with long delays, characterized by tabulated data. The algorithm is based on partitioning the data in the time-domain and subsequently, approximating each partition via delayed rational functions. This results in a compact low-order macromodel in the form of delayed differential equations, which can be efficiently analyzed in the time-domain using circuit simulators.

Scattering Domain Passivity Verification and Enforcement of Delayed Rational Functions

This letter introduces new algorithms for passivity verification and compensation of macromodels constructed from delayed rational functions in the scattering domain. For passivity verification, a frequency-dependent generalized eigenvalue is formulated, which is used to accurately determine the regions of passivity violation. For passivity compensation, first order perturbation theory is used to iteratively perturb the residues of the system until passivity is achieved. Numerical results validating the proposed algorithms are presented.

Passivity verification and enforcement of delayed rational function macromodels from networks characterized by tabulated data

Passivity has become a critical issue while modeling high-speed networks characterized by tabulated data. For modules containing long delays, macromodeling based on delayed rational functions has been gaining popularity in recent years. However, there are currently no passivity verification or enforcement methods available for such macromodels. To address this issue, this paper proposes passivity verification and enforcement algorithms for delayed rational function macromodels of high-speed modules, characterized by tabulated data. Necessary theoretical foundation and validating examples are presented.

Delay Extracted Stable Rational Approximations for Tabulated Networks With Periodic Reflections

This letter presents an efficient and stable macromodeling formulation for electrically long high-speed modules characterized by tabulated data. The resulting system of delay differential equations contains a reduced number of delayed rational terms for networks with dominant periodic reflections leading to faster transient simulations. A method is also presented for macromodel stability verification and enforcement.

Passive model-order reduction of RLC circuits with embedded time-delay descriptor systems

In this paper, a new algorithm for passive model-order reduction of RLC networks with embedded general Time-Delay Descriptor (TDD) systems is presented. In addition, a new passivity verification algorithm for TDD systems is developed. Numerical results validating the proposed algorithms are also presented.

Passivity verification and enforcement of delayed rational approximations from scattering parameter based tabulated data

Ensuring the passivity of macromodels obtained from tabulated data has become a critical issue for accurate signal integrity analysis. For delayed rational function based macromodels derived in the admittance domain, the issue of passivity has recently been addressed. In this paper, passivity verification and compensation algorithms for delayed rational function based macromodels derived in the scattering domain are presented. Numerical results validating the proposed algorithms are presented.

Passivity Verification of Delayed Rational Function Based Macromodels of Tabulated Networks Characterized by Scattering Parameters

In this paper, a generalized theory for passivity verification of delayed rational function (DRF) macromodels representing electrically long networks that are characterized by multiport tabulated scattering parameters is presented. In the proposed approach, passivity verification of DRF macromodels is formulated as a quasi-periodic frequency-dependent generalized eigenvalue problem, using which, the necessary search region for passivity violations is reduced to just a single period along the imaginary axis. Necessary theoretical foundations and the related proofs are developed. Further, a computationally more efficient method based on half-Hamiltonian size frequency-dependent generalized eigenvalue problem is developed. Numerical validations for both the full-size and half-size formulations are also presented.

Efficient passivity verification of delayed rational function macromodels from networks characterized by tabulated data

In this paper, an efficient passivity verification algorithm is presented for delayed rational function based macromodels obtained from tabulated scattering parameter data. The proposed approach is based on a new half-size frequency dependent generalized eigenvalue problem, which reduces the necessary search region to a single finite interval along the imaginary axis. Numerical results validating improved efficiency of the proposed algorithm over previous techniques are also presented.

Passive macromodeling of transmission line type interconnects characterized by tabulated data

An algorithm is presented for the construction of a delay extraction-based macromodel for a single set of transmission lines from tabulated H, Y, S, or Z parameters. The algorithm determines a unique logarithm of the exponential stamp of the H parameters. The delay extraction-based passive compact transmission-line macromodeling (DEPACT) algorithm can then be used to construct a passive and causal macromodel for SPICE simulation.