Fast and Accurate Wide-Band Analysis of Antennas Mounted on Conducting Platform Using AIM and Asymptotic Waveform Evaluation Technique

The adaptive integral method (AIM) in conjunction with the asymptotic waveform evaluation (AWE) technique is presented for wide-band analysis of antennas in the presence of electrically large conducting platforms. In the AWE technique, the Padé approximation solution obtained by matching the coefficients of the Taylor series (namely, moments) is utilized to achieve fast frequency sweeping. Besides the calculation and storage of the high order frequency derivatives of impedance matrices, the AWE technique requires repeatedly solving the linear system for the moments. Thus the AIM is employed to reduce matrix storage and to accelerate all the matrix-vector multiplications in both the linear system for the moments and the iterative solver. Furthermore, a localized self-box inclusion (SBI) preconditioner is used to accelerate the solution procedure of the linear system for the moments. Finally, three numerical examples are given and discussed. The input admittance and return loss of the antennas over a given frequency band are obtained by AIM and AIM-AWE method, respectively. The good agreements show that the proposed hybrid technique can greatly reduce the computation time without loss of accuracy.