System and method for dividing the carrier center frequency of an rf modulated signal by a non-integer divisor

An apparatus comprising:

• a digitally-controlled oscillator (DCO) circuit configured to output a phase-modulated carrier output signal having a carrier center frequency that is a non-integer multiple of a desired carrier center frequency;
• an injection-locked ring oscillator (ILRO) configured to generate a plurality of phases of a phase-modulated carrier output signal at a plurality of outputs of the ILRO;
• a fractional frequency division circuit coupled to the plurality of outputs of the ILRO, the fractional frequency division circuit configured to sequentially-select, using a multiplexer (MUX), successive outputs of the plurality of outputs corresponding to successive phases of the plurality of phases to generate a decoupled fractional frequency output signal having a center frequency equal to an integer multiple of the desired carrier center frequency;
• and
• an integer frequency division circuit coupled to the fractional frequency division circuit and configured to generate, based on the decoupled fractional frequency output signal, a desired phase-modulated carrier output signal, the desired phase-modulated carrier output signal having a generated carrier center frequency equal to the desired carrier center frequency.