Tuner suitable for integration and method for tuning a radio frequency signal
AssigneeSilicon Laboratories Inc.
InventorRichard A. Johnson
Life of this patent
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Abstract
A tuner (200) includes a direct digital frequency synthesizer (206) and a mixer (220). The direct digital frequency synthesizer (206) has an output terminal for providing a digital local oscillator signal having a frequency chosen to mix a desired channel to baseband. The mixer (220) has a first input terminal for receiving a tuned radio frequency signal, a second input terminal coupled to the output terminal of the direct digital frequency synthesizer (206), and an output terminal for providing an in-phase baseband signal.
Claims40
A tuner comprising:
- a direct digital frequency synthesizer having an output terminal for providing a digital local oscillator signal having a frequency chosen to mix a desired channel to baseband;
- and
- a mixer having a first input terminal for receiving a tuned radio frequency signal, a second input terminal coupled to said output terminal of said direct digital frequency synthesizer, and an output terminal for providing an in-phase baseband signal.
A tuner comprising:
- a first mixer having a first input terminal for receiving a tuned radio frequency signal, a second input terminal for receiving a first digital local oscillator signal having a frequency chosen to mix a desired channel to baseband, and an output terminal for providing an in-phase baseband signal;
- a second mixer having a first input terminal for receiving said tuned radio frequency signal, a second input terminal for receiving a phase-shifted first digital local oscillator signal, and an output terminal for providing a quadrature baseband signal;
- means for processing at least one of said in-phase baseband signal and said quadrature baseband signal at baseband to provide a processed in-phase signal and a processed quadrature signal;
- and
- an up conversion mixer having a first input terminal for receiving said processed in-phase signal, a second input terminal for receiving said processed quadrature signal, a third input terminal for receiving a second digital local oscillator signal having a predetermined frequency, a fourth input terminal for receiving a phase-shifted second digital local oscillator signal, and an output terminal for providing a tuned intermediate frequency signal.
A method for tuning a signal comprising the steps of:
- generating a digital local oscillator signal having a frequency chosen to mix a desired channel to baseband;
- receiving a tuned radio frequency signal;
- and
- mixing said tuned radio frequency signal with a digital local oscillator signal having to provide an in-phase baseband signal.
A method for tuning a signal comprising the steps of:
- receiving a tuned radio frequency signal;
- -mixing said tuned radio frequency signal to baseband using a first digital local oscillator signal and a phase-shifted first digital local oscillator signal to form an in-phase baseband signal and a quadrature baseband signal, respectively;
- processing at least one of said in-phase baseband signal and said quadrature baseband signal at baseband to form a processed in-phase signal and a processed quadrature signal;
- mixing said processed in-phase signal and said processed quadrature signal to an intermediate frequency using a second digital local oscillator signal and a phase-shifted second digital local oscillator signal, respectively, to form first and second intermediate frequency signals;
- and
- combining said first and second intermediate frequency signals to form an intermediate frequency output signal.
Dependencies are inferred from the claim text.