An integrated circuit comprises a dual port modulator and a voltage controlled oscillator (VCO). The dual port modulator has a first input for receiving a transmitter modulation signal, a first output for providing a fractional portion of a high port modulation signal, a second output for providing a integer portion of the high port modulation signal, and a third output for providing a low port modulation signal. The VCO is coupled to the dual port modulator and has a first input for receiving the fractional portion of the high port modulation signal, a second input for receiving the integer portion of the high port modulation signal, a third input for receiving a tuning signal based on the low port modulation signal, and a first output for outputting an RF signal. The dual port modulator provides a signed single bit signal for generating the fractional portion of the high port modulation signal.