In this paper a new method is proposed for obtaining the complete synchronization curves of injected oscillators or analog frequency dividers, using harmonic balance (HB) commercial simulators. The bifurcation loci on the input power-input frequency plane, globally providing the circuit operating bands can also be obtained. The new method offers an invaluable aid to microwave designers, avoiding the need for specific in-house simulation tools and taking advantage of the flexibility and friendliness of standard commercial software. The method is illustrated by means of its application to the design of a frequency divider by two, obtaining for the first time, to our knowledge, complete synchronization curves and bifurcation loci from a commercial simulator. Under some modifications, the method is applicable to tuned circuits. Simulation and measurements of a MMIC VCO are shown for experimental validation
