Patent ID: 6952569

Claim:
A transmitter comprising: a voltage-controlled oscillator (VCO) that generates a transmit signal having a frequency f Tx ; a modulated signal source that generates an LO signal modulated with audio or data information, the modulated signal having a frequency f LO ; a mixer that mixes the transmit signal with the LO signal to produce an IF signal having a frequency f IF , a first divider that divides the LO signal frequency f LO by an integer M to generate a first comparison signal having a frequency f CF ; a second divider that divides the IF signal frequency f IF by an integer N to generate a second comparison signal having a frequency f CF ; a phase detector coupled to the first and second comparison signals that compares the phases of the signals and outputs a control voltage to the VCO proportional to any phase differences between the signals; a multiplier that multiplies the LO signal by an integer K before the LO signal is supplied to the mixer; and wherein when f LO >f Tx , the relationship between the transmit and LO signal frequency is expressed as f Tx = f LO ⁢ ⁢ KM - N M , and when f LO<f Tx , the relationship between the transmit and LO signal frequency is expressed as f Tx = f LO ⁢ KM + N M .