| 摘要 |
PROBLEM TO BE SOLVED: To eliminate an abnormal surge voltage without deteriorating the electrical characteristic of a high frequency amplifier circuit covering up to a specific high frequency band by connecting in series at least two pairs of diodes which are connected in parallel to each other with their polarities set opposite to each other and connecting these pairs of diodes between the input or output side of the high frequency amplifier circuit and the ground. SOLUTION: Three pairs of diodes 4a which are connected in parallel to each other with their polarities set opposite to each other are connected in series between an output line 2 of a high frequency amplifier circuit 1 used to a CATV(cable television), etc., and the ground. In such a constitution, a protection circuit 4 is obtained. Meanwhile, a protection circuit 5 is also obtained by connecting in series two pairs of three diodes 5a in the forward direction and connecting these pairs of diodes 5a in parallel to each other with their polarities set opposite to each other. As a result, the circuit 1 can be protected from the abnormal serge voltage without deteriorating its distortion and impedance characteristics covering up to a high frequency band of 1000 MHz. |
