METHOD AND DEVICE FOR DEMODULATING AMPLITUDE MODULATED RADIO-FREQUENCY SIGNALS Russian patent published in 2009 - IPC H03D1/12 

FIELD: physics.

SUBSTANCE: in the method and device for demodulating amplitude modulated signals, demodulation takes place between the source of amplitude modulated radio-frequency signals and a low-frequency (LF) load and is carried out using a four-terminal network (FTN), double-electrode nonlinear element and a low-pass filter (LPF). Spectra of amplitude modulated signals are decomposed using the nonlinear element, and using the low-pass filter, the information low-frequency signal is separated, amplitude of which varies according to the law of variation of the amplitude modulated input signal. A high-frequency (HF) load is connected between the output of the four-terminal network and the low-pass filter. A nonlinear element is connected between the signal source and the four-terminal network into a longitudinal circuit. The four-terminal networks is made from at least three reactive impedors, parametre values of which are chosen such, that a given amplitude modulation depth is provided for, defined by a given value of the modulus of transmission coefficient of demodulation in the second state of the nonlinear element and defined by the condition of physical realisability of the value of the modulus of transmission coefficient of demodulation in the first state of the nonlinear element.

EFFECT: provision for given values of modulus of transmission coefficient of demodulation in two states of a nonlinear element (NE), defined by two extreme values of the level of input amplitude modulated signal.

2 cl, 3 dwg