Kenneth S. Kundert’s research while affiliated with Cadence Design Systems, Inc. and other places

... The authors themselves have performed extensive simulations to achieve an understanding of the behavior of the semiconductor structure in an MOS transistor at such a high frequency [27,28]. To this end, Harmonic Balance (HB) analysis [29], which precisely describes the nonlinear processes stemming from the nonlinearities of semiconductor equations, was adopted. Despite its potential, this approach has received so far little attention from the THz community. ...

Reference:

Design Optimization of a THz Receiver Based on 60 nm Complementary Metal-Oxide-Semiconductor Technology

... The chosen approach is based on the circuit simulation method named "harmonic balance-harmonic Newton" [19] . [19] is proposed to determine suitable initial values in advance. ...

Reference:

Frequency-selective Optimization of Periodic Gate Control Signals in DC/DC Converters for EMI-reduction

... To circumvent these difficulties, mixed frequency-time approaches(MFT) [2,3] have been proposed. The methods in [2,3] exploit the fact that many circuits of engineering interest have a strongly nonlinear response to only one input, such as the clock in the case of a switched-capacitorcircuit, or local oscillator in the case of a mixer, but respond only in a weakly nonlinear manner to other inputs. ...

Reference:

Efficient Computation of Quasi-Periodic Circuit Operating Conditions via a Mixed Frequency/Time Approach.

... Außerdem sind Leitungsgleichungen im Frequenzbereich beschrieben und lassen sich im Zeitbereich nur schwer formulieren. Weil normalerweise immer nur der eingeschwungene Zustand einer Schaltung von Interesse ist, hat sich für Mikrowellenschaltungen die Berechnung nach dem Prinzip der harmonischen Balance (Harmonic Balance [5]) durchgesetzt. Bei dieser Methode wird die Schaltung in einen linearen und einen nichtlinearen Teil zerlegt. ...

Reference:

Monolithische GaAs FET- und HBT-Oszillatoren mit verbesserter Transistormodellierung /

... Fortunately many circuits of interest are designed to operate near a time-varying, but quasi-periodic, operating point. Some of these circuits can be analyzed by assuming one of the circuit inputs produces a periodic response that can be directly calculated by steady-state methods [4], thus avoiding long transient simulation times. Any other (time-varying) circuit inputs are treated as small-signal by linearizing the circuit around the periodic operating point. ...

Reference:

Efficient Computation of Quasi-Periodic Circuit Operating Conditions via a Mixed Frequency/Time Approach.

... This leads to a class of methods which here will be referred to as harmonic balance methods. Harmonic balance methods can be formulated in both the time and the frequency domain, with the main difference being that the solution variables are time samples in the former, and Fourier coefficients in the latter [10,26]. Within the electronics community, harmonic balance is most often formulated in the frequency domain [10], and the modern version of harmonic balance is acredited to Nakhla and Valch [34]. ...

Reference:

Minimizing Aliasing in Multiple Frequency Harmonic Balance Computations

... Energy harvesting technologies for wireless sensors on transmission lines are evolving rapidly, enabling real-time monitoring and predictive maintenance [18]. Innovative approaches for transmission line simulation using S-parameter data [19] and parameter identification through state estimation [20] have enhanced modeling accuracy. Advanced fault diagnosis and prognosis techniques, including artificial intelligence methods, improve network reliability [21]. ...

Reference:

State-of-the-art techniques and algorithms for swift and precise fault detection and protection in transmission lines

... We find the model reduction approach of this time-varying system (1) by a reformulated LTI discretization of (1) using the Euler discretization method [3], [4]. Let us consider the differential algebraic state-space form of a LTI multi-input and multi-output (MIMO) system Eẋ(t) = Ax(t) + Bu(t), ...

Reference:

Efficient system reduction modeling of periodic control systems with application to circuit problems

... For these weakly nonlinear systems it is possible to apply time-varying Volterra series as an extension to the standard description, as in [4][5], where no time-varying aspect is considered. The quasiperiodic boundary conditions for a Volterra description can, in principle, be obtained using a method very similarly to either of the two methods proposed for steady-state simulation ; namely [1][3], or [2] . In this paper, we choose the latter approach since it provides a more straightforward finitedifference formulation as well as other benefits [2]. ...

Reference:

Modeling nonlinear communication ICs using a multivariate formulation

... However, this process requires a long simulation time with a very short time step. Another classical approach for predicting the behavior of STM-based non-reciprocal circuits is the harmonic balance (HB) method [14], where the circuit is split into a linear subcircuit and a nonlinear subcircuit. In the HB method, the elements in the liner section are expressed with their frequency domain admittance or impedance, and the analysis is done in the Fourier domain [15]. ...

Reference:

Attention-Based Deep Neural Network for High-Dimensional Microwave Modeling of Non-Reciprocal Bandpass Filters