Switching radiometer

The structure and algorithm of a switching radiometer intended for measuring the intensity of biological objects´ UHF EM radiation are discussed. The proposed switching radiometer automatically keeps the temperature of the equivalent load terminating resistor equal to the applicator antenna temperature irrespective of its position on the biological object. The equality between the applicator antenna and equivalent load resistance is maintained at any object temperature. This ensures a balance between the noise levels of the applicator antenna and the antenna equivalent, as well as consistency of the microwave amplifier self-noise when the antenna is switched to its equivalent. Thus, the applicator antenna self-noise is corrected and the spurious modulation of the microwave amplifier self-noise is eliminated, offering increased accuracy of EM radiation power measurements deep inside biological objects displaying varying temperatures or intensities of pathological processes.