US Patent 7480331 Method and device for pulse width modulation

A method and a device are proposed for the conversion of a quantized signal into a pulse width modulated signal, wherein dependent on a signal value of the quantized signal in each case a pulse duration of a pulse is determined within a period of the pulse width modulated signal, in which the pulse width modulated signal assumes a first value, while in the remainder of the period it assumes a second value, and wherein a phase position of the pulse is varied within the period of the pulse modulated signal from period to period in such a manner that energy of the pulse width modulated signal is distributed across a broad frequency spectrum. In one case, this takes place by means of parallel switched SD modulators and a vector controller.