Reactance of Small Antennas

The voltage difference between the two arms of the antenna is On the right is Fig. 86 from [2]. In general the electric field is related to the scalar and vector potentials by E = −∇V − ∂A/∂t = −∇V + iωA, assuming a time dependence of the form e−iωt. Then, ∫ 2 1 E · dl = V1 − V2 + iω ∫ 2 1 A · dl. However, close to a small linear dipole antenna the electric field is much larger than the magnetic field (see, for example, [3]), and the contribution of the vector potential to the electric field in negligible in this region.