Fast Frequency Sweep Using Asymptotic Waveform Evaluation Technique and Thin Dielectric Sheet Approximation

The thin dielectric sheet (TDS) surface integral equation (SIE) combined with the asymptotic waveform evaluation (AWE) technique is proposed to efficiently analyze wideband properties of thin dielectric layers such as radome and composite materials. The TDS SIE is an efficient method for analyzing the thin dielectric layer because the number of unknowns of the TDS SIE is fewer than that of the volume integral equation (VIE) and the condition number of the TDS impedance matrix is small. In addition, the AWE technique based on a Taylor series and the Pade approximation is a well-known method for fast frequency sweep. Therefore, the combination of these two methods makes analysis of the thin dielectric layer efficient in the wide frequency region because the advantages of each method are shown at the same time. In order to determine the valid bandwidth of the approximated results for arbitrary problems using the TDS combined with the AWE, the bandwidth estimation approach for the AWE is applied. The results of the proposed method for closed and open structures agree very well with the exact solutions and reveal the capability for fast frequency sweep.