| 摘要 |
PROBLEM TO BE SOLVED: To provide an intermediate-frequency coupling circuit for a television tuner which eliminates an inductor for impedance matching by increasing the degree of trap attenuation of a lower contiguous channel frequency component of a selected channel without increasing the degree of attenuation of the selected channel. SOLUTION: The intermediate-frequency coupling circuit 1, connected between an intermediate-frequency amplification stage 5 and a filter 6 for video signal selection, is composed of a parallel circuit composed of a series-connected impedance matching resistance 11 and a second capacitor 14 connected in parallel to a series circuit of an inductor 12 and a 1st capacitor 13 and such a trap circuit for lower contiguous channel removal that the series circuit has series resonance to a selected channel frequency component and the parallel circuit has parallel resonance to the lower contiguous channel frequency of the selected channel.
|
