Television tuner with double quadrature mixing architecture
AssigneeMStar Semiconductor, Inc.
InventorsFucheng Wang, Chao-Tung Yang, Yi Lu
Life of this patent
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Abstract
A television tuner employs a double quadrature mixing architecture to frequency-translate VHF/UHF TV signals to various standard IF frequencies. In the television tuner, a quadrature mixer converts the input television signal into a first in-phase signal and a first quadrature-phase signal according to a first reference signal, and a double quadrature mixer converts the first in-phase signal and first quadrature-phase signal into a second in-phase signal and a second quadrature-phase signal according to a second reference signal, and a polyphase filter filters the second in-phase signal and second quadrature-phase signal to produce an output signal.
Claims19
A television tuner for frequency-translating a television signal, comprising:
- a first local oscillator for generating a first reference signal with a fixed frequency;
- a quadrature mixer for receiving and converting the television signal into a first in-phase signal and a first quadrature-phase signal according to the first reference signal;
- a second local oscillator for generating a second reference signal which has a frequency tunable according to a desired channel to be frequency-translated;
- a double quadrature mixer for receiving and converting the first in-phase signal and first quadrature-phase signal into a second in-phase signal and a second quadrature-phase signal according to the second reference signal;
- and
- a polyphase filter for receiving and filtering the second in-phase signal and second quadrature-phase signal to generate an output signal.
Dependencies are inferred from the claim text.