Method for measuring the spectral distribution of electromagnetic radiation intensity and spectrometer of millimetric and far-infrared ranges for effecting same

A spectrometer of millimetric and far-infrared ranges for measuring the spectral distribution of electromagnetic radiation, comprising:

• an electromagnetic radiation modulator disposed in the path of said electromagnetic radiation and having an input, a first output and a second output, said input receiving the electromagnetic radiation to be investigated;
• an electromagnetic radiation receiver comprising superconducting weak links, for conversion of the spectral distribution of electromagnetic radiation to an electric signal by means of a direct integral Hilbert transform, the resistance R [ohms] and operating temperature T [K] of said links selected to meet the condition RT<740 f.sub.1, where f.sub.1 [cm.sup.-1 ] is the required spectral resolution, said receiver having a first input, a second input and an output, said first input being optically coupled to said first output of said electromagnetic radiation modulator;
• a phase-sensitive detection unit having a first input, a second input and an output, said first input being connected to said second output of said electromagnetic radiation modulator and said second input being connected to said output of said electromagnetic radiation receiver;
• a processing unit for subjecting the electric signal measured as a function of a direct integral Hilbert transform parameter to an inverse integeral Hilbert transform, said processing unit having a first input, a second input and an output which serves as the output of the spectrometer, said first input being connected to said output of said phase-sensitive detection unit;
• a control unit having a first output and a second output, said first output being connected to said second input of said electromagnetic radiation receiver and said second output being connected to said second input of said processing unit.

A spectrometer for determining the frequency spectrum of microwave or infrared radiation signals, comprising:

• means for modulating the radiation to be measured;
• a frequency scannable receiver for receiving the output of said modulating means;
• a control unit for applying a variable scanning voltage to said receiver, the value of said scanning voltage being proportional to a Hilbert transform parameter;
• a phase detector having an input coupled to the output of said receiver;
• means for coupling a reference signal from said modulator to said phase detector, whereby the output of the phase detector is a direct Hilbert transform of the spectral distribution of said radiation signals when said scanning voltage is scanned through the entire frequency range of said signals;
• means coupled to the output of said phase detector for obtaining the spectral distribution of said radiation signals by deriving the inverse integral Hilbert transform of said phase detector output.