Method to Estimate in-band Scattering Cross Section of Vivaldi Array Antenna

The in-band scattering of the antenna is the superposition of the antenna mode scattering and structural mode scattering. In this paper, the scattering, resulted from the scattering sources on the edges of the array, is proved to be the main contribution to the structural mode scattering. Moreover, the antenna mode scattering of the array can be estimated through the radiation of the antenna element. Therefore, the in-band scattering cross section (SCS) can be estimated by the superposition of the estimated antenna mode and structural mode scattering. The X-band Vivaldi array antenna is fabricated and measured. The measured monostatic SCS results are in an agreement with the simulations, showing the correctness of the analysis and the effectiveness of the estimation method.