A radio-frequency (RF) apparatus capable of transmitting RF signals
includes transmitter path circuitry. The transmitter path circuitry
includes a voltage-controlled oscillator (VCO) that generates an output
signal. The frequency of the output signal of the VCO circuitry is
adjustable in response to a first control signal and a second control
signal. The transmitter path circuitry also includes a first feedback
circuitry and a second feedback circuitry that are responsive to the
output signal of the VCO circuitry. The first feedback circuitry provides
the first control signal to the VCO circuitry. The first control signal
coarsely adjusts the frequency of the output signal of the VCO circuitry
to a desired frequency. The second feedback circuitry supplies the second
control signal to the VCO circuitry. The second control signal fine tunes
the frequency of the output signal of the voltage-controlled oscillator
circuitry to the desired frequency.