Near Field Characterization of an Imaging System Based on a Frequency Scanning Antenna Array

This contribution describes the concept of frequency scanning for imaging applications. The designed frequency scanning antenna array, which works in Ku frequency band, is used for the sectoral illumination of the scene under investigation, enabling the recovery of information restricted to the selected area. While the proposed idea simplifies beam scanning techniques with respect to mechanical or electrically-controlled scanning systems, the price-to-pay is the limitation on the amount of scattered field information. The near field radiation of the frequency scanning antenna array is characterized through an equivalent source model to assess accurately the incident field used in the imaging algorithm. This analysis also enables the evaluation of the frequency steering performance of the antenna in the near field, validating its use for the proposed application.