Near-field Characteristics
The near-field itself is further divided into the reactive near-field and the radiative near-field. The "reactive" and "radiative" near-field designations are also a function of wavelength (or distance). However, these boundary regions are a fraction of one wavelength within the near-field. The outer boundary of the reactive near-field region is commonly considered to be a distance of 1/2π times the wavelength (λ/2π or 0.159 x λ) from the antenna surface. The radiative near-field (also called the "Fresnel region") covers the remainder of the near-field region, from λ/2π out to λ (one full wavelength).
Read more about this topic: Near And Far Field