| 摘要 |
PROBLEM TO BE SOLVED: To receive a standard television signal and a high definition television signal. SOLUTION: This receiver adopts a single superheterodyne system for an NTSC signal where a 3rd mixer 22 converts the NTSC signal into an IF signal and an NTSC signal IF filter separates a selected channel from the IF signal and adopts a double superheterodyne system for a high definition television signal where a 1st mixer 10 converts the high definition television signal into a 1st IF signal with a frequency of 10 GHz or over, a 2nd mixer 13 converts the 1st IF signal into a 2nd IF signal whose frequency band is equal to that of the IF signal of the NTSC signal and a high definition television signal IF filter 15 that is a SAW filter separates a selected channel from the 2nd IF signal. A band pass filter with an in-band flatness and a low group delay deviation is adopted for an IF filter 11 to which the 1st IF signal from the 1st mixer 10 is supplied.
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