Patent ID: 8401493

Claim:
A frequency synthesizer, comprising: a signal reference circuit that generates a signal reference; a first phase-locked loop circuit path connected to said signal reference circuit and comprising, a first phase-locked loop circuit comprising a phase detector and a voltage controlled oscillator connected thereto and a feedback loop extending from the voltage controlled oscillator to the phase detector and a frequency divider positioned within the feedback loop, and a phase-locked loop output at the voltage controlled oscillator through which an RF signal is generated at a first frequency; an integer frequency divider connected to the phase-locked loop output and operative to receive the signal therefrom and to divide the first frequency of the signal output from the first phase-locked loop circuit by an integer number; a tunable bandpass filter connected to said integer frequency divider that is tuned for selecting a harmonic frequency to obtain a fractional frequency division to produce a local oscillator signal used for a first frequency specific digital television application; a second phase-locked loop circuit path connected to said signal reference and comprising, a second phase-locked loop circuit having an output; a direct digital synthesizer connected to said second phase-locked loop circuit; a mixer connected to said direct digital synthesizer and receiving a digital television service signal for mixing with signals for said direct digital synthesizer and producing a local oscillator signal used for a second frequency specific digital television application; and a television signal frequency divider that receives the digital television service signal and generates a plurality of digital television service signals of different frequencies, and a switch connected between the mixer and frequency divider for selecting a desired frequency to be mixed with signals from the direct digital synthesizer.