| 摘要 |
A television tuner for three frequency ranges (I, II, III) comprises a common antenna connection (4) for corresponding input filter circuits. The input filter circuits (1, 2, 3) of the two higher frequency ranges can be connected to and disconnected from the antenna connection by means of switches (11, 12). The switches (11, 12) are each located between the antenna connection (4) and the associated input filter circuit (2, 3). To improve matching of the input filter circuit (3) and to simplify the configuration of the circuit, the antenna connection (4) is arranged in the proximity of an input filter circuit (1, 2) of the two lower-frequency frequency ranges (I, II). In addition, the switch (12) for the highest frequency range (III) is connected to the end of a coupling conductor (5) which is spaced closest to the antenna connection (4). Both ends of the coupling conductor (5') are connected to ground by means of a respective capacitor (5a, 5b) and the coupling conductor is coupled with an input circuit conductor (6') of the input filter circuit (3) of the highest frequency range (III).
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