1. Give the details about Near field & Far field of the antenna.

Near Field and Far Field of an Antenna:

1. Near Field: The near field is the region that is very close to the antenna. In this region, the electromagnetic field of the antenna is complicated and does not have a simple relationship with the distance from the antenna. The near field is further divided into two regions: the reactive near field and the radiating near field.

   • Reactive Near Field: This is the region closest to the antenna. In this region, the electric and magnetic fields are out of phase by 90 degrees, and the power alternates between the electric and magnetic fields, but does not radiate away from the antenna. The boundary of this region is approximately given by a distance of λ/2π from the antenna, where λ is the wavelength of the signal.

   • Radiating Near Field: This is the region beyond the reactive near field but still relatively close to the antenna. In this region, the power begins to radiate away from the antenna, but the field still does not have a simple relationship with distance. The boundary of this region is approximately given by a distance of 2D^2/λ from the antenna, where D is the largest dimension of the antenna.

2. Far Field: The far field is the region beyond the near field where the electromagnetic field of the antenna is essentially independent of distance and the field pattern is independent of the distance from the antenna. In this region, the electric and magnetic fields are in phase and the power radiates away from the antenna. The boundary of this region is approximately given by a distance of 2D^2/λ from the antenna. The far field is the region typically of most interest in antenna theory because it is the region in which the antenna radiates power.