RADIO WAVE DOPPLER CHANNEL WITH SERVICEABILITY SELF-TEST SYSTEM, PREDOMINANTLY FOR SECURITY DETECTOR Russian patent published in 2001 - IPC

FIELD: radio protection equipment. SUBSTANCE: radio wave Doppler channel with serviceability self-test system, predominantly for security detector, has SHF generator whose one output is coupled to transmitting antenna, whose another output is connected to one of inputs of balance mixer which other input is linked to receiving antenna. Output of balance mixer is connected to input of low-frequency filter whose output is linked to input of low-frequency amplifier which output is connected to one of inputs of processor. One of outputs of processor is connected to SHF generator and phase modulator of reflected SHF signal. Processor can incorporate digital Fourier filter with frequency equal to frequency of modulator. Channel can incorporate control changing effective range of radio wave channel which is in the mix of low-frequency amplifier and its output is connected via unit controlling position of control changing effective range to another input of processor. EFFECT: determination of fact of masking of radio wave channel, detection of unauthorized and involuntary change of range of efficiency of this channel caused by malfunction. 2 cl, 2 dwg