A Fast Newton Algorithm for the Analysis and Design of Microwave Oscillators and VCOs

The paper introduces a second-generation harmonic-balance algorithm providing a very powerful simulation and design tool for microwave VCOs and oscillators of all kinds. The oscillator tuning characteristic is determined by a fast Newton iteration yielding order-of-magnitude CPU time savings with respect to conventional optimisation-based approaches. The program accepts arbitrarily user-defined nonlinear device models, thus allowing the nonstandard behaviour of integrated varactors to be accurately accounted for. An example of application is presented, concerning the simulation of a monolithic broadband VCO tuned by two on-chip planar Schottky varactor diodes.