| 摘要 |
A cable input selector is provided to enable first and second shielding circuits to connect an antenna input terminal or a cable input terminal to a switch IC or disconnect the antenna input terminal or the cable input terminal from the switch IC according to a selection signal applied from a control terminal, thereby improving shielding properties between the antenna input terminal and the cable input terminal when the cable input selector is off. A cable input selector comprises an antenna input terminal(31) and a cable input terminal(32), an output terminal(33), a control terminal(34), a switch IC(Integrated Circuit)(35), and first and second shielding circuits(43,44). Each of high frequency broadcasting signals of predetermined schemes is applied to each of the antenna input terminal and the cable input terminal. The output terminal outputs a high frequency broadcasting signal selected out of the high frequency broadcasting signals inputted to the antenna input terminal and the cable input terminal. A selection signal indicating whether to select any high frequency broadcasting signal is inputted to the control terminal. The switch IC applies a broadcasting signal inputted from one of the antenna input terminal and the cable input terminal to the output terminal according to the selection signal applied from the control terminal. The first and second shielding circuits are equipped respectively between the antenna input terminal and the switch IC and between the cable input terminal and the switch IC, and are operated in a connection status or a disconnection status according to the selection signal to connect the antenna input terminal or the cable input terminal to the switch IC or disconnect the antenna input terminal or the cable input terminal from the switch IC. |
