Patent ID: 6895063

Claim:
A digital tuner comprising a single frequency changer of one of a zero intermediate frequency changer and a near-zero intermediate frequency changer, said frequency changer comprising: an oscillator arrangement; a first multiplier having a first input for receiving an input signal in a first frequency band, and a second input connected to said oscillator arrangement; and said oscillator arrangement comprising a first oscillator for supplying a first signal in said first frequency band to said second input of said first multiplier, said first oscillator having a control input a second oscillator for producing a second signal in a second frequency band outside said first frequency band, said first and second oscillators forming part of a first phase-locked loop which comprises a first programmable divider, a first comparator having an output, a first input connected via said first programmable divider to said first oscillator, and a second input connected to said second oscillator, and a first control loop connected between said output of said first comparator and said control input of said first oscillator, said first control loop comprising an amplifier and a loop filter whose bandwidth is at least as large as the bandwidth of the input signals supplied to an antenna input, and a fixed frequency reference oscillator, said first oscillator being phase-locked to said second oscillator, and said second oscillator being phase-locked to said reference oscillator.