Apparatus and method for reducing harmonic interference generated by a clock signal

In a device that includes a signal generator and a filter, wherein the signal generator produces a first signal including a fundamental frequency component and harmonic frequency components having power levels, wherein the filter filters a second signal over a predetermined frequency bandwidth to produce a filtered signal, and wherein the filtered signal is susceptible to interference from at least one of the harmonic frequency components having a frequency within the predetermined frequency bandwidth, an apparatus for substantially reducing the interference of the at least one harmonic frequency component with the filtered signal, the apparatus comprising:

• a frequency spreading signal generator for producing a frequency spreading signal;
• and
• a signal modulator for modulating the first signal with the frequency spreading signal to produce a modulated signal including modulated harmonic frequency components, wherein the power level of at least one modulated harmonic frequency component, corresponding to the at least one harmonic frequency component interfering with the filtered signal, is spread over a frequency bandwidth greater than the predetermined frequency bandwidth causing the power level of the at least one modulated harmonic frequency component within the predetermined frequency bandwidth to decrease, whereby the interference of the at least one harmonic frequency component with the filtered signal is substantially reduced.