What if we model the dipole as a flat ribbon?

Modeling the Center-Driven Dipole with Microstripes

Round wires can be modeled as flat ribbons with a width equal to 4 times the round-wire radius. In this case, the dipole antenna can be modeled as a 2-mm wide ribbon. The source model requires a slight modification as shown in Figure 8. The source wire ends need to be located some distance away from the ribbon edge, in this case 2.5 mm. The result in Figure 9 shows that the resonant frequency and the impedance at 150 MHz are nearly the same obtained using the round-wire model; however, the simulation time was cut in half.

Fig. 8. Ribbon model

Fig. 9. Comparison between ribbon model and cylinder model