Frequency domain steady-state simulation of oscillators

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.