Apparatus and method for generating a modulated clock signal including harmonics that exhibit a known sideband configuration

Patent, 2004

An apparatus and method are provided that helps address the electromagnetic compatibility issues arising from the integration of digital circuitry and analog circuitry within a wireless mobile terminal (for example). Basically, the apparatus includes a clock generator capable of generating an unmodulated clock signal and a modulator capable of generating a modulated clock signal having selected clock pulses omitted from the unmodulated clock signal. The modulated clock signal includes a fundamental frequency and a plurality of harmonic frequencies that exhibit a known sideband configuration. The known sideband configuration can be selected such that there would be less harmonic content in a band where co-located analog circuitry could be adversely affected by electro-magnetic interference from the modulated clock signal.