METHOD AND DEVICE FOR MEASURING TEMPERATURE USING MICROWAVE RADIATION

摘要

The invention concerns a radiometric method for measuring the temperature of an object (2) such as a material or a body for use by manufacturers of radiometric devices and used in medicine, agri-food and industrial sector, which consists in: sensing the microwave radiation of said object (2) via an antenna (3) which has an antenna-unknown material reflection coefficient rho ; processing the waves (12) sensed by the antenna with processing means consisting of an amplifier (5) and a detector (6), said amplifier being connected to the antenna by a given characteristic impedance line (4) and transmitting a noise in input which is then reflected by the antenna with an initial shift phi i, producing a correlation effect of the noise which is in the detector output in the form of a correlation voltage of the noise Vcor which perturbs the temperature measurement. The invention is characterised in that it consists in: injecting by inductive coupling a constant noise in the given characteristic impedance line (4) which is commuted on the antenna (3) and on at least a reference (22) whereof the reflection coefficient value is known, to determine the value of the antenna-material reflection coefficient rho ; modifying the structure of the elements of the radiometer and accurately adjusting the physical and/or dimensional characteristics of said elements to eliminate the component of the correlation noise voltage Vcor in the temperature measurement of the material, whatever the initial shift phi I and the value of the antenna-material reflection coefficient rho .