US Patent 7132863 Digital clock frequency doubler

A digital clock frequency doubler for increasing an input frequency of an input clock signal includes an input block, and a generator block. The input block receives the input clock signal, and generates a pulse signal having an ON period equal to the input clock signal period. The generator block is coupled to the input block. The generator block receives the pulse signal and divides a period of the pulse signal by a period of a high frequency digital signal and then generates an output clock signal with an output frequency that is about two times the input frequency.