| 摘要 |
PURPOSE:To detect a fault of a circuit through which a burst signal is transmitted easily with simple circuit constitution accurately by detecting whether or not the level of an output signal of the transmission circuit is within a prescribed range and using an exclusive OR with an input signal to detect the fault. CONSTITUTION:An intermediate frequency band directional coupler 10 (same as 5-7), a diode detector 11 and a DC amplifier 12 are fitted to an output/input section (or transmission frequency converter input section) of a fault detection circuit, a comparator 13 is connected to obtain a rectangular wave in response to an input burst signal. On the other hand, a comparator 14 detecting that the level is over L1 and a comparator 15 detecting that the level is below L2 are fitted to a signal detection circuit of the output side of the transmitter. Thus, when both rectangular wave signals are exclusively ORed by exclusive OR circuits 16, 17, 18, a fault of a device (in this case a transmission frequency converter 2 and a power amplifier 3) is detected independently of the presence of the signal. |
