Methods and systems for producing a low-power, low-phase noise oscillating signal using a self-injection locking oscillator. Preferred embodiments include, for example, producing, using an oscillator, a signal having a base frequency component and an Nth harmonic component, wherein N is a selected integer and N>1; filtering said signal through a bandpass filter with Q factor ≥5, said filter configured to pass said Nth harmonic component as a filtered Nth harmonic component; and injecting said filtered Nth harmonic component into said oscillator to thereby self-injection lock said base frequency of said signal.