  Although the MUltiple SIgnal Classification (MUSIC) algorithm has
demonstrated suitability as a microwave imaging technique for detecting
anomalies, there is a fundamental limit that it requires a switching device to
be used which permits an antenna to transmit and receive signals
simultaneously. In this paper, we design a MUSIC-type imaging function using
scattering parameter data to find small anomaly and explore its mathematical
structure. Considering the investigated structure, we confirm that the imaging
performance is highly dependent on the antenna configurations and suggest an
arrangement of antennas to enhance imaging performance. Simulation results with
synthetic data are displayed to support theoretical result.
