FIELD: physics.
SUBSTANCE: invention can be used for demodulating (DM) phase-shift keyed, as well as phase modulated (PM) signals by converting a phase modulated signal into an amplitude-phase modulated (APM) signal through formation of a slop of the amplitude-frequency curve of the demodulator with given ratio of moduli m21 of transmission coefficients at two given frequencies f1, f2, corresponding to extreme values of variation of frequency of the input phase modulated signal and subsequent amplitude demodulation. Phase modulated signals are demodulated without using a reference oscillation generator and a parallel oscillatory circuit, with conversion of phase modulated signals into amplitude-phase modulated signals using the high-frequency part of demodulation with given amplitude modulation depth of amplitude-phase modulated signals in the high-frequency load. Phase modulated signals undergo demodulation in the method and device for demodulating phase modulated signals. Demodulation takes place using a linear reactive four-terminal network (FTN), a double-electrode nonlinear (NLE) element, a low-pass filter (LPF) and a selective load. The phase modulated signal is converted to an amplitude-phase modulated signal by transmitting it to the right- and left-side slope of the amplitude-frequency curve (AFC). The low-frequency component of the amplitude-phase modulated signal is transmitted to a differentiating or integrating circuit. The spectrum of the amplitude-phase modulated signal is decomposed to low- and high-frequency components using the nonlinear element. Using the low-pass filter, the information low-frequency signal is separated, amplitude of which varies according to the law of variation of the phase of the phase modulated input signal. The double-electrode nonlinear element is connected between the four-terminal network and the high-frequency load into a transverse circuit. The four-terminal network is made from at least reactive impedors, parametres of which are chosen from the required values of amplitude modulation depth of the amplitude-phase modulated signal.
EFFECT: increased noise-immunity of the receiver.
2 cl, 4 dwg
