Frequency domain steady-state simulation of oscillators

by Duan, Xiaochun

The focus of this work is on developing algorithms for frequency domain

steady-state analysis of oscillators. Convergence problems associated with the

frequency domain harmonic balance simulation of oscillators have been examined.

Globally convergent homotopy methods have been combined with the harmonic

balance method for robust high-Q oscillator simulation. Various homotopy

options are evaluated leading to an algorithm that is applicable to a wide variety

of oscillator circuits. Two new approaches have also been developed for the

simulation of ring oscillators using the harmonic balance method. These include a

single-delay cell method and a multiple-probe method. The new methods that

have been proposed are robust compared to traditional methods and readily

converge for a wide range of single-ended and differential oscillators. They

enable harmonic balance simulation of “difficult-to-converge” oscillator circuits.