Human-body temperature measurements using contact radiometer with built-in calibrators

We have studied theoretically and experimentally the accuracy of human-body temperature measurements using a modulation-type contact radiometer in the UHF-EHF ranges. The radiometer uses a nontraditional structure that includes a reflection modulator. Comparing the traditional method of measurements used in the calibration of the temperature scale against external standards of radiation with calibration against the built-in noise generator and standard short-circuitor, we see that the measurement accuracy is approximately the same in both methods. However, the accuracy of the method set forth in this paper is limited mainly by the imperfections of the short-circuiter, whereas the errors of the traditional method are related to the inhomogeneity of the object under study with respect to the reflection factor. Experimental studies were carried out with human-body phantoms in the 8-mm range of wavelengths.