Cadence Design Systems, Inc.

Yu Zhu

Xiaolue Lai

Dan Feng

In a circuit simulation tool in a computer system having one or more computer processors and computer-readable storage, a method for characterizing a driven oscillator circuit having an oscillator coupled to a time-varying input signal includes retrieving information provided in a circuit description of the oscillator circuit. The method also includes forming a frequency-domain harmonic balance equation for the oscillator circuit using the retrieved information provided in the circuit description of the oscillator circuit. The harmonic balance equation includes a first differential operator in a frequency domain of the input signal and a product of a differential operator in a second frequency domain of the oscillator and a frequency variable of the oscillator. The frequency variable is independent of the frequency domain of the input signal. The method further includes solving the harmonic balance equation to obtain a waveform description of the oscillator circuit.

Method and system for steady state simulation and noise analysis of driven oscillators

An apparatus and method for performing periodic noise (Pnoise) simulation with full spectrum accuracy is disclosed herein. Noise contributions of a circuit under consideration are identified and separated for different computation treatment. The different computation treatment results in computational efficiency without sacrificing accuracy of simulation results.

Shooting Pnoise circuit simulation with full spectrum accuracy

Embodiments may include methods, systems, and computer-readable storage mediums that may be used to simulate phase noise for an oscillator circuit. In some embodiments, a method of simulating phase noise for an oscillator circuit may include providing an oscillator circuit description. A time-domain representation of a small signal phase noise of the oscillator circuit description may be determined. A shooting Newton matrix representation of the time-domain representation of the small signal phase noise may be generated. The shooting Newton matrix representation may be augmented to include a phase-shift factor and a pinning equation. The augmented shooting Newton matrix representation may be solved to determine a signal output of the oscillator circuit.

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Campbell, CA, United States of America

Yu Zhu