Calculation method and calculation device

A computer-implemented method for improving the accuracy of circuit simulation for a high-frequency element by calculating, from measured S-parameter data, a frequency-dependent scattering-parameter matrix using a six-terminal distributed-constant model that captures parasitic effects unaccounted for by conventional lumped models, the method comprising:

• acquiring, as inputs, a first voltage applied to a first terminal of the high-frequency element, a second voltage applied to a second terminal of the high-frequency element, and a frequency of a high-frequency signal input to the first terminal;
• retrieving values of L parameters of a distributed-constant circuit that were previously extracted by fitting measured S-parameter matrices of the high-frequency element across at least N bias conditions, N being an integer of two or more;
• calculating, using a first model of an intrinsic circuit whose lumped-element values vary as a function of at least one of the first voltage and the second voltage and a second model of the distributed-constant circuit, a 2×2 scattering-parameter matrix of a circuit network between the first and second terminals at the frequency, wherein L is an even integer of two or more, the distributed-constant circuit is interconnected among six terminals comprising the first, second, and third terminals and a fourth terminal for inputting the high-frequency signal to the intrinsic circuit, a fifth terminal for outputting the high-frequency signal from the intrinsic circuit, and a sixth terminal for supplying the reference potential to the intrinsic circuit, and each of L/2 impedance elements has a first end connected to one of the six terminals and a second end connected to a different one of the six terminals and is characterized at the frequency by two real valued impedance parameters comprising a resistance component and a reactance component;
• and
• outputting the calculated scattering-parameter matrix for use in generating a frequency-dependent netlist and for subsequent computer-based simulation of the high-frequency element across a target operating band.

A calculation device for improving the accuracy of circuit simulation for a high-frequency element by generating, from measured S-parameter data, a frequency-dependent distributed-constant model that captures parasitic effects unaccounted for by conventional lumped models, the high-frequency element comprising a first terminal configured to receive a high-frequency input signal, a second terminal configured to output the high-frequency signal, and a third terminal configured to receive a reference potential, the calculation device comprising:

• a memory;
• and
• a processor coupled to the memory, the processor configured to:
• (a) acquire, for each of at least N bias conditions, an S-parameter matrix characterizing small-signal behavior between the first terminal and second terminal, each bias condition being defined by a first voltage applied to the first terminal and a second voltage applied to the second terminal, N being an integer of two or more;
• (b) initialize a first circuit model that represents an intrinsic region of the high-frequency element with lumped-element values that vary as a function of at least one of the first and second voltages;
• (c) initialize a second circuit model that represents a distributed-constant circuit interconnected among six terminals and comprising L/2 impedance elements, each impedance element having a first end connected to one of the six terminals and a second end connected to a different one of the six terminals, the six terminals comprising the first, second, and third terminals and a fourth terminal for inputting the high-frequency signal to an intrinsic circuit, a fifth terminal for outputting the high-frequency signal from the intrinsic circuit, and a sixth terminal for supplying the reference potential to the intrinsic circuit, being an even integer of two or more;
• (d) iteratively adjust, by numerical optimization based on the acquired S-parameter matrices, two real-valued impedance parameters—a resistance component and a reactance component—for each of the L/2 impedance elements until simulated S-parameter matrices generated from the first and second circuit models converge, within a predetermined error bound, toward the acquired S-parameter matrices;
• and
• (e) output the converged resistance and reactance components as extracted physical parameters usable to create a frequency-dependent netlist for subsequent computer-based simulation of the high-frequency element across a target operating band.

A calculation device for improving the accuracy of circuit simulation for a high-frequency element by calculating, from measured S-parameter data, a frequency-dependent scattering-parameter matrix using a six-terminal distributed-constant model that captures parasitic effects unaccounted for by conventional lumped models, the high-frequency element comprising a first terminal configured to receive a high-frequency input signal, a second terminal configured to output the high-frequency signal, and a third terminal configured to receive a reference potential, the calculation device comprising:

• a memory;
• and
• a processor coupled to the memory, the processor configured to:
• receive, as inputs, a first voltage applied to the first terminal, a second voltage applied to the second terminal, and a frequency of the high-frequency signal;
• retrieve values of L parameters of a distributed-constant circuit that were previously extracted by fitting measured S-parameter matrices of the high-frequency element across at least N bias conditions, N being an integer of two or more;
• calculate, using a first model of an intrinsic circuit whose lumped-element values vary as a function of at least one of the first voltage and the second voltage and a second model of the distributed-constant circuit, a 2×2 scattering-parameter matrix of a circuit network between the first and second terminals at the frequency;
• wherein L is an even integer of two or more, the distributed-constant circuit is interconnected among six terminals comprising the first, second, and third terminals and a fourth terminal for inputting the high-frequency signal to the intrinsic circuit, a fifth terminal for outputting the high-frequency signal from the intrinsic circuit, and a sixth terminal for supplying the reference potential to the intrinsic circuit, and each of L/2 impedance elements has a first end connected to one of the six terminals and a second end connected to a different one of the six terminals and is characterized at the frequency by two real valued impedance parameters comprising a resistance component and a reactance component;
• and
• output the calculated scattering-parameter matrix for use in generating a frequency-dependent netlist and for subsequent computer-based simulation of the high-frequency element across a target operating band.