| 摘要 |
PURPOSE:To detect interference in spite of electric field intensity by varying the bias voltage of a rectifier circuit responding to the electric field intensity. CONSTITUTION:The titled device is constituted of a logarithmic detection circuit 1 which performs the logarithmic detection of the signal of a reception wave including a disturbing wave, and the rectifier circuit 9 with constitution where the DC bias voltage is varied corresponding to the DC component of the logarithmic detection circuit 1, and which takes out only a high frequency component from a logarithmic detecting signal from the circuit 1, and obtains a DC value corresponding to the amplitude of the component. When a noise component is superposed in a weak electric field, the bias voltage of a full-wave rectifier circuit 7 is decreased by the output of a DC amplifier 8. In such a way, it is possible to prevent an integral value from being increased due to the noise component, and to take out only the size of the high frequency component due to the interference. |
