Question

What is first Fresnel Zone?

Answer 1

1. The elliptical region between the transmitter antenna and the receiver antenna, this region is determined by the distance between the antennas and the frequency of the wireless wave. This is called Fresnel Zone.
   
2. The difference between the direct path and the indirect path that touches a single point on the edge of the Fresnel zone is called First Fresnel Zone.
3. To establishing Fresnel zones, first determine the RF line of sight.
4. Which in simple terms is a straight line between the transmitting and receiving antennas.
5. First Fresnel zone formula is $r_{1max}=\sqrt{\frac{c*D}{4*f}}$
   Where $f$ represents wireless beam frequency, $\mathrm{c}$speed of light in air, and $D$ is the distance between the antennas.
6. In radio communications, a Fresnel zone is one of a number of concentric ellipsoids.
7. These concentric ellipsoids define volumes in the radiation pattern of a circular aperture.