RADIOMETER WITH THREE-POINT MODULATION Russian patent published in 2014 - IPC G01R29/08 

FIELD: radio engineering, communication.

SUBSTANCE: radiometer with three-point modulation comprises series-connected receiving antenna, three-input microwave switch, high frequency amplifier, square-law detector, low frequency amplifier, synchronous filter, synchronous detector, multiplication-division unit and recorder, wherein modulation control signals from a modulation control device are transmitted to control inputs of the microwave switch, synchronous filter and synchronous detector. The device also includes "hot" and "cold" reference matched loads and structurally connected thereto thermal sensors of the "hot" and "cold" reference matched loads, outputs of which are connected to inputs of the multiplication-division unit, and a heating element. The device includes a solid-state "cold" noise source, the output of which is connected to the input of the microwave switch, a thermal sensor for the solid-state "cold" noise source, structurally connected to the solid-state "cold" noise source, the output of which is connected to the input of the modulation control device, a microwave circulator, the first input of which is connected to the output of the microwave switch; the second input of the microwave circulator is connected to the "cold" reference matched load; the output of the microwave circulator is connected to the input of the high frequency amplifier. The circulation direction of the microwave circulator is selected from the second input to the first input and from the first input to the output.

EFFECT: high measurement accuracy.

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