| 摘要 |
1,203,870. Function generators. BENDIX CORP. 9 Dec., 1969 [4 Jan., 1968], No. 58343/68. Heading G4G. [Also in Division H4] Apparatusfor generating a constant false alarm rate video signal in response to an input signal containing noise, in which the rate per second at which signal level exceeds threshold due to noise is held constant for noise variation, comprises (Fig. 1) plural tandem identical video amplifiers 10-1 to 10-5 receiving signal input at 9 with outputs passing to fullwave detectors 12-1 to 12-5, whose outputs are fed in succession to a chain of alternate adders 16-2 to 16-5 and unilateral video amplifiers 14-1 to 14-4, whose output is capacitance coupled to 19. The video amplifiers from 10-5 to 10-1 produce successively diminishing adder inputs containing video and D.C. components; the latter being capacitance filtered; so that if input noise increases the output of each amplifier stage is increased for successive blocking from 10-5 to 10-1, so that the associated detectors generate only D.C., while the detectors of unblocked amplifiers yield both A.C. and D.C. to the adder. Thus the A.C. component remains constant and the D.C. component increases with noise, so that a constant A.C. signal is produced after D.C. filtration irrespective of noise input. In a more sophisticated modification (Figs. 2A, 2B, not shown), the video amplifiers comprise differential transistors followed by transistor followers; the fullwave detectors pairs of shunt diodes interconnected by transistor followers, and series resistance adders fed from the outputs of the diode transistor followers and from the preceding differential transistor adder amplifiers. Power supplies to the several amplifiers and intermediate D.C. levels are Zener stabilized and isolated. |
