A Portable Through-Wall Microwave Imaging System

A microwave imaging system requires the design and implementation of an imaging algorithm, a sufficiently sensitive/accurate vector network analyzer, and antennas. This work presents a simple imaging algorithm, design and implementation of a low-cost VNA and antennas that are able to operate at 4 - 6 GHz. The commercial VNAs are of general purpose and are too expensive for microwave imaging applications. The design trade-offs applied to VNA are presented and implemented circuits are demonstrated. Using the presented VNA, a hand-held imaging system is implemented that extracts scattering parameters to create the target image. S-parameters obtained from the preselected filters with the designed VNA are provided to demonstrate the quality of the design. Target images are created for a couple of commonly used walls to demonstrate the overall system performance.