A Microwave Radiometer for Deep Noninvasive Diagnostics of Thermal Fields Inside a Biological Object

摘要

A microwave radiometer for a wavelength of 10.5 cm with a frequency band of received signals of 200 MHz is described. It allows one to perform remote noninvasive temperature measurements deep in a biological object. The use of a modified null-reception method as the basis of the instrument operation made it possible to reduce the influence of the reflectance at the location of the contact between an applicator antenna and a body on the measurement accuracy and increase the dynamic characteristics during mapping of a biological object. At a storage signal time of 1 s, the measurement accuracy was 0.047 K. The output-signal changes were within 0.1 K when the reflectance was varied from 0.1 to 0.5.