METHOD OF DEMODULATING PHASE MODULATED RADIO-FREQUENCY SIGNALS AND DEVICE TO THIS END Russian patent published in 2009 - IPC H03D3/26 

FIELD: physics; radio.

SUBSTANCE: invention relates to wireless communication and can be used for demodulating phase-shift keyed, as well as phase modulated signals through transformation of a phase modulated signal to an amplitude-phase modulated signal through formation of the slope of the amplitude-frequency characteristic of the demodulator with given ratio of modules m₂₁ of transmission coefficients at two given frequencies f₁, f₂, which correspond to extreme values of change of frequency of the input phase modulated signal and subsequent amplitude demodulation. The method and device for demodulating phase modulated signals involves transmission of a phase modulated signal a demodulator, made from a linear reactive four-terminal network, two-electrode non-linear element and a selective load. The phase modulated signal is transformed to an amplitude-phase modulated signal through transmission of this signal to the right or left slope of the amplitude-frequency characteristic. The low-frequency component of the amplitude-phase modulated signal is transmitted to a differentiating or integrating circuit respectively. Using the non-linear element, the spectrum of the amplitude-phase modulated signal is broken down to high-frequency and low-frequency components. Using a low-pass filter, the information low-frequency signal is picked up, the amplitude of which varies according to the law of variation of the phase of the phase modulated input signal. The non-linear element is connected between the phase modulated signal source and the four-terminal network into a longitudinal circuit. The four-terminal network is made from at least two reactive two-terminal networks, resistance of which is chosen under the condition which provides for given amplitude modulation depth M₂₁ of the amplitude-phase modulated signal at m₂₁>1 or , at which for m₂₁>1 and f₁>f₂, the left slope of the amplitude-frequency characteristic is formed, for f₁<f₂ - the right slope is formed, and for m₂₁<1 and f₁>f₂ the right slope is formed and for f₁>f₂ the left slope is formed.

EFFECT: provision for demodulation of phase modulated signals without use of a reference oscillation generator and a parallel oscillatory circuit, with transformation of a phase modulated signal to an amplitude-phase modulated signal using the high frequency part of demodulation at given amplitude modulation depth of amplitude-phase modulated signals on a high-frequency load, which increases noise immunity of the receiver.

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