An Enhanced Gap Source Model

An enhanced gap source model is introduced by combination with Rao-Wilton-Glisson (RWG) basis functions. For decades, the stability of the delta gap source model remains a big problem. The RWG basis with triangulation and the feeding-edge model have been widely used in numerical analysis of antennas. Since the feeding-edge model uses a single RWG edge as the driving source and neglects the gap width effect, the resulting current undergoes sharp transition across the gap and thus the model is highly sensitive to the choice of the feeding edge. Consequently, the feeding-edge model suffers instability in calculations of current and input impedance. To circumvent these pitfalls, this enhanced gap source model uses multiple RWG edges and impulsive function to formulate the feeding behavior. This new gap source model exhibits significant improvements on both accuracy and stability. Numerical results are included to illustrate improved accuracy and stability of this new model by virtue of several typical antennas.