A breast microwave sensing system utilizing a fixed antenna array: system design and feasibility of material characterization using transmission measurements

A new system was built to serve as a tool in transitioning from a pre-clinical breast imaging rotating-radar bed system to a portable, low-cost medical device. This study presents the design of the new microwave sensing system and the feasibility of estimating an average relative permittivity using the transmission coefficient. The system was designed for multistatic operation in air, collecting S-parameter measurements using a 360° static array of 24 Vivaldi antennas. The system operates in the range of 700 MHz to 8 GHz. A two-antenna array setup was used to estimate the relative permittivity of wood by transmission coefficient measurements. The RMSE of the frequency-averaged relative permittivity was $0.1 \pm 0.2$ when using horn antennas, and $0.4 \pm 0.2$ when using Vivaldi antennas.