Exemplary embodiments of the invention provide a reference signal
generator having a controlled quality ("Q") factor. An exemplary
apparatus to generate a harmonic reference signal includes a reference
resonator, such as an LC-tank, which generates a first reference signal
having a resonant frequency, and a plurality of reactance modules
couplable to the reference resonator. Each reactance module comprises one
or more reactance unit cells, and each reactance unit cell comprises a
reactance element coupled in series to a switching element. In exemplary
embodiments, the reactance element is a capacitor having a predetermined
unit of capacitance, and the switching element is a transistor having a
predetermined resistance when in an off state. The ratio of capacitance
to resistance is substantially constant for all reactance modules of the
plurality of reactance modules.