Extraction of electromagnetic target poles from multiple scattered fields with damped Min-norm method

In this study, the estimation of complex natural resonance frequencies (target poles) by using damped minimum-norm (DMin-norm) method is presented. The method mainly utilizes from the scattered fields belonging to multiple aspect angle/polarization cases of a target in resonance scattering region. By employing DMin-norm algorithm, the proposed method constitutes a function from which target poles can be efficiently extracted as its roots. However, the method in its conventional form should be executed as many times as the number of scattered fields to collect sufficient number of resonance frequencies. Therefore, the method is further improved in terms of computational time to acquire target poles with a single process for multiple scattered data. The described method is applied to a dielectric sphere having high number of target poles and good agreement between estimated and theoretical poles is observed.