| 摘要 |
FIELD: physics. ^ SUBSTANCE: device for incoherent reception of amplitude telegraphy (AT) signals has cascade-connected band-pass filter, intermediate frequency amplifier connected in an automatic gain control circuit, amplitude detector, low-pass filter and threshold element. The automatic gain control circuit comprises cascade-connected count pulse generator with fixed threshold, pulse counter, adder, register and digital-to-analogue converter, as well as a logic OR element and an XOR element, wherein the initial state of the pulse counter is characterised by a number M=f0 Ts, where f0 is the AT signal-carrier frequency, Ts is duration of the element of the AT signal. Use of discrete elements in the automatic gain control circuit enables to keep parameters of the receiver constant on the interval of each elementary transmission of the AT signal and their measurement at the boundary between transmissions in accordance with results for continuous analysis of the ratio of the signal level and interference at the output of the intermediate frequency amplifier. ^ EFFECT: higher noise immunity of receiving amplitude telegraphy signals. ^ 2 dwg |
