Question

Which of the following is known as Non Radiative region?

(a) Far field region

(b) Near filed region

(c) Radiative Field

(d) Reactive Field

This question was addressed to me in an interview.

Question is taken from Near Field and Far Field topic in section Modern Antennas & Antenna Measurements of Antennas

Answer 1

Right option is (d) Reactive Field

To elaborate: Radiative and reactive field regions are the parts of the near field region.  The Far field region is greater than \(\frac{2D^2}{λ}\)and near field region is less than \(\frac{2D^2}{λ}\). Reactive region is also known as non- Radiative region and is next to antenna. The Radiative region is also known as Fresnel region.