Adaptive selection of sampling interval in frequency domain for estimating the poles of scatterers

In this paper, the matrix pencil (MP) method has been utilized for estimating the complex natural resonances from IFFT of calculated frequency responses. The novelty is that frequency sampling interval is investigated. The responses are usually computed by the accurate method of moments (MoM) in frequency domain, which is time-consuming. So, the frequency sampling interval's effect on results should be analyzed, and a scheme for adaptive choice of frequency sampling interval is proposed in this paper. The scheme is validated by a special example, a perfect conducting sphere. Lastly, poles of a complex radar target, a missile model, are calculated by the proposed method and compared with other available data.