| 摘要 |
PURPOSE:To obtain a burst detection pulse from an obtained burst wave through a waveform shaping device by using an adder, an attenuator and a delay line having a length being a half period (t= tau/2) of the burst wave, delaying the burst wave at the delay line by tau/2 and feeding back the result again to the input side through the attenuator. CONSTITUTION:The waveform (a) of a burst signal is given to an adder 11 and the output of the adder 11 is inputted to a delay line 12 having a length being an odd number [t=(2k-1).tau/2] of the half period of the burst wave. Moreover, the output of the delay line 12 passes through an inverse amplifier 13 and is attenuated by an attenuator 15 having an attenuation ratio eta (eta<=1), goes to a waveform retarded by (t) and attenuated by eta, and is fed to the other input of the adder 11. The burst wave delayed by (t) at the delay line 12 and the burst wave not retarded are added by the adder 11 and then fed to the delay line 12 again, a positive feedback loop is established and the burst wave is increased at every circulation of the loop and becomes the vaveform (d). The increased burst wave is extracted from the output of the adder 11 and inputted to a waveform shaping device 14 to obtain a burst detection pulse (e).
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