Patent ID: 9035682
Filing Date: 2015-05-19
Classification: H03C,H03L

Abstract:
1. A single port frequency modulator, comprising: a reference oscillator that produces a reference signal at a reference frequency; a phase detector that compares the reference signal to a modulation signal to produce a control signal; a loop filter that filters the control signal to produce a filtered control signal; a voltage controlled oscillator that produces an intermediate signal having a frequency dependent on the filtered control signal; an integer loop that multiplies the frequency of the intermediate signal to produce a multiplied intermediate signal, wherein the frequency of the multiplied intermediate signal is higher than the frequency of the intermediate signal by a multiplication factor which is an integer or an integer plus one half; an output divider that divides the frequency of the multiplied intermediate signal to produce a desired output signal at a desired output frequency; a multi-modulus feedback divider block that divides the frequency of the multiplied intermediate signal by a sequence of divider input numbers to produce the modulation signal that is provided to the phase detector; and a fractional-N modulator that provides the sequence of divider input numbers to the multi-modulus feedback divider block responsive to an integer input, a fractional input, and a modulation input provided to the fractional-N modulator; wherein single port modulator is comprised in a radio device having a receive mode and a transmit mode, the feedback divider block includes programmable divider that produces the modulation signal, the single port modulator further comprising a divider switch that selectively provides the intermediate signal, through a receive prescaler, to the programmable divider in a receive mode, and the multiplied intermediate signal, through a transmit prescaler, to the programmable divider in a transmit mode, wherein a power consumption reduction is achieved in the receive mode.