Microwave Tomography Based on Phase Difference from Small-Interval Antenna Slippage

Multi-target echo positions in two dimensions can be achieved by combining time-domain signals of vector network analyzer (VNA) (using two ports and two antennas) and orderly variation of optical path contributed from singleantenna slippage. In this study, the positioning formulas are derived from the concept that is similar to Bragg's law of X-ray diffraction. To effectively obtain multi-echo two-dimensional image, an approach similar to Klimontovich equation in plasma physics is adopted. The proposed method has successfully been verified by a series of randomly arranged three-target experiments. The image reconstruction results precisely showed the positions of the targets.