METHOD FOR RADIO LOCATION OF OBJECTS WITH RADAR-ABSORBENT COATING Russian patent published in 2014 - IPC G01S13/02 

FIELD: radio engineering, communication.

SUBSTANCE: method involves irradiating an object with microwave transmitter pulses and recording the reflected echo signal with a receiver, wherein irradiation is carried out at two close frequencies and the echo signal is recorded at difference frequency thereof. Generation of the difference frequency occurs in the composite coating material owing to its nonlinearity. Due to that the transmitter operates in the centimetre wavelength range and the receiver operates in the metre wavelength range, there is virtually no absorption of the echo signal by the thin coating layer, wherein the accuracy of determining coordinates of a target does not deteriorate since the azimuth and elevation angle are situated in the direction of the short-wave and narrow-directed antenna of the transmitter.

EFFECT: high sensitivity and range of action.