Digital CATV tuner
OwnerSyuuji Matsuurainventor
Life of this patent
Estimating the term…
Abstract
In the digital CATV tuner, gain of a reception signal of a plurality of frequency bands is controlled by a PIN AGC circuit, a reception signal for each of the frequency bands selected from the reception signal is high-frequency amplified by a high-frequency amplifier circuits, a local oscillation signal corresponding to the frequency band to be received from the plurality of the local oscillation signal from local oscillation circuits and the high-frequency amplified reception signal for each of the frequency band are mixed by a mixer to output an intermediate frequency signal, and a digital signal component is obtained from the intermediate frequency signal. Therefore, various characteristics can be improved.
Claims4
A digital CATV tuner receiving a reception signal including a digital signal of a plurality of frequency bands, comprising:
- a gain control circuit controlling gain of said reception signal of the plurality of frequency bands;
- an input tuning circuit selecting a reception signal for each of the frequency bands from said reception signal output from said gain control circuit;
- a high-frequency amplifier circuit high-frequency amplifying said reception signal for each of the frequency bands selected by said input tuning circuit;
- a plurality of local oscillation circuits each outputting a local oscillation signal corresponding to each of said frequency bands;
- a local oscillation switching circuit selecting a local oscillation circuit corresponding to a frequency band to be received from said plurality of local oscillation circuits;
- a mixer circuit mixing said reception signal for each of the frequency bands high-frequency amplified by said high-frequency amplifier circuit, and said local oscillation signal from said local oscillation circuit selected by said local oscillation switching circuit to output an intermediate frequency signal;
- and
- a digital filter obtaining a digital signal component from said intermediate frequency signal output from said mixer circuit.
Dependencies are inferred from the claim text.