Method for measuring the temperature of a material by using microwave radiation

A device for measuring the temperature T.sub.x of a given material or object, using microwave radiation, comprising:

• an antenna for receiving signals;
• means for processing the received signals;
• and
• a selectable intercalary electrical line having a length L, of a given impedance as a function of the input impedance of said processing means, electrically connecting said antenna and said processing means, wherein said length L of said intercalary electrical line is selected to be very large in relation to the wavelength of the signals processed so as render the correlation voltage negligible with respect to the signal voltage.

A process for measuring the temperature T.sub.x of a given material or object, using microwave frequency radiation, comprising the steps of:

• receiving microwave radiation emitted via an antenna having a reflection coefficient .vertline.R.sub.o x .vertline..sup.2 ;
• routing the signals received to signal processing means;
• and
• intercalating between the antenna and the signal processing means a line having a length L that is very large in relation to the wavelength of the signals processed, such that the correlation factor of the signal processing means is negligible;
• wherein said routing step further comprises routing via the length L of the intercalary line to an input of the processing means with a power gain .tau..sub.g, an input noise temperature T.sub.e and an output noise temperature T.sub.a, to obtain an output voltage at an output of the signal processing means, wherein the output voltage is characterized by the following equation:
• V.sub.s =g .gamma.[T.sub.x (1-.vertline.R.sub.o x .vertline..sup.2)+T.sub.e .vertline.R.sub.o x .vertline..sup.2 +T.sub.a
• said process further comprising the step of calculating all the parameters periodically, by modifying cyclically the structure of the signal processing means.

A device for measuring the temperature T.sub.x of a given material or object, using microwave radiation, comprising:

• an antenna for receiving signals;
• means for processing the received signals, comprising a direct amplification microwave frequency receiver, followed by a square law detector and preceded by a microwave frequency multi-channel switch;
• and
• a selectable intercalary electrical line having a length L, of a given impedance as a function of the input impedance of said processing means electrically connecting said antenna and said processing means wherein said length L of said intercalary electrical line is selected to be very large in relation to the wavelength of the signals processed so as render the correlation voltage negligible with respect to the signal voltage.