Antenna pattern analysis using higher-order FDTD method

Directly applying the conventional FDTD method to open space problems such as the computation of antenna patterns has not been a practical approach yet. Using a fourth-order spatial difference has the effect of lowering the phase error resulting from numerical dispersion, even with much coarser spatial grid size. This feature makes the fourth-order FDTD algorithm an applicable method for antenna pattern analysis. This paper describes a procedure for applying the S24 FDTD algorithm to direct computation of the far-field pattern of antennas. This method has the advantage of consuming less computing resources while maintaining accuracy. Numerical results are compared with those obtained from the near-to-far field transformation and cavity models and show good agreement.