Monostatic Pulsed Ultrawideband Radar Antenna for Studying Biological Rhythms of the Human Body and Internal Inhomogeneities of Dielectric Objects

This paper presents a study of the prerequisites and the original way of transition from a quasi-monostatic antenna system to a monostatic one as applied to ultrawideband pulsed contact radar subsurface sounding at shallow depths. For this purpose, the joint application of ultrawideband electric “Bow-Tie” and magnetic “Bi-Quad” antennas is investigated. The mutual arrangement proposed in this work allows reducing to zero the distance between the centers of the antennas in the plane orthogonal to the direction of signal emission-reception. The results of full-scale tests with the corresponding processing of the obtained ensembles by the example of probing the human body for the detection and determination of the parameters of biological rhythms and a tree trunk 58 cm in diameter showed satisfactory results for the radar with a central frequency of 1.5 GHz. At the same time, the suppression of the useful signal received due to the application of the described design was only 2.3 dB at an acceptable level of the direct signal, which does not lead to overloading of the radar stroboscopic receiver input.