| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a digital STB tuner capable of outputting a signal suitable for QAM demodulation. <P>SOLUTION: A PIN attenuator circuit 30 in the digital STB tuner 1 is connected to an output side of a high pass filter 5, and a PIN attenuator circuit 31 is connected to the input side of high frequency amplifier input tuning circuits 9 to 11. A buffer amplifier 30 is connected between the PIN attenuator circuits 30 and 31. The PIN attenuator circuit 30 attenuates a received signal to prevent a buffer amplifier 32 from being saturated. Further, the PIN attenuator circuit 31 attenuates the signal to prevent high frequency AGC circuits 12 to 14 from being saturated. <P>COPYRIGHT: (C)2003,JPO</p> |
