| 摘要 |
PURPOSE:To realize a narrow band with a simple constitution and without using any special power supply nor a bias circuit, by securing the tuning amplifying characteristics for a logical gate circuit by making use of its linear action region and at the same time having a waveform shaping action by making use of the switching action region of said gate circuit. CONSTITUTION:For a circuit 10, the negative feedback quantity is set at 0 with the resonance frequency of a resonance circuit 11 and then varies with other frequencies in response to the resonance characteristics. In other words, the circuit 10 containing resistances 4 and 5, a coil 6, a capacitor 7 and a logic gate circuit 2 has the tuning amplifying characteristics with its amplification degree set at 0 at a frequency region having a large negative feedback quantity. When a signal containing a resonance frequency is supplied, the negative feedback quantity is set at 0 to perform a logical action with limited amplitude. That is, the circuit 2 works in a nonlinear region to the resonance frequency component contained in a rectangular wave to be extracted. Thus the apparent negative feedback loop gain is reduced, and therefore the rectangular waveform is kept at an output. As a result, a waveform having a high degree of sharpness is obtained. |
