Microwave time delay spectroscopic methods and apparatus for remote interrogation of biological targets

摘要

Remote interrogation of biological targets is accomplished in accordance with the present invention by method and apparatus wherein a microwave signal is generated which varies in frequency from a first frequency to a second frequency in a predetermined time period. The signal is divided into two signals, one of which is propagated through a test channel comprising a transmitting antenna for transmitting the signal through the target, and a receiving antenna for receiving the signal transmitted through the target, and the other of which is propagated through a reference channel providing a fixed time delay of propagation. The propagated signals are detected and mixed to produce a time delay spectrum wherein the frequency of each spectral line represents the instantaneous difference in the frequencies of the detected signals.