| 摘要 |
PURPOSE:To obtain RF signals of two different bands selectively from a terminal by providing a series circuit comprising a coil and a unidirectional switch element supplying a bias current to a series circuit comprising unidirectional switch elements such as diodes and blocking the passing of the RF signals of a broadcast band. CONSTITUTION:A voltage VB is applied in the reception of an FM broadcast, diodes 28, 30 are turned on and the other end of a primary coil 25a is brought nearly to a ground potential, the RF signal from ab antenna connection terminal INA2 is transmitted from the primary coil 25a of a transformer 25 to a secondary coil 25b and then fed to a capacitor 13. On the other hand, since no voltage VB is fed at the reception of an AM broadcast, the diodes 28, 30 are turned off and the RF signal from the antenna connection terminal INA2 is fed to an output terminal OUT1 via a capacitor 24, the primary coil 25a, a capacitor 26 and a coil 27. |
