User's Manual
Table Of Contents
- 195Ea Chapter 0 - Front Cover 195Ea
- 195Ea Chapter 0 - Table of Contents
- 195Ea Chapter 1 - Introduction
- 195Ea Chapter 2 - Starting Out
- 195Ea Chapter 3 - Example Applications
- 195Ea Chapter 4 - Utilities and Features
- 195Ea Chapter 5 - Web Configuration Manager
- 195Ea Chapter 6 - Serial Configuration and Applications
- 195Ea Chapter 7 - Repeating and Mesh Networking
- 195Ea Chapter 8 - Antenna Setup
- 195Ea Apx A - FCC Information
- 195Ea Apx B - Specifications
- 195Ea Apx C - Interface Ports
- 195Ea Apx D - Radio Configuration
- 195Ea Apx E - Security
- 195Ea Apx F - Troubleshooting
CHAPTER 8
ANTENNA SETUPS
Revised: 17 Jan 12 8-12 EST P/N AA107A
FRESNEL ZONE
The Fresnel zone shows the ellipsoid spread of the radio waves around the visual line-of-sight after they leave the antenna (see
figure above). This area must be clear of obstructions or the signal strength will be reduced due to signal blockage. Typically,
20% Fresnel Zone blockage introduces little signal loss to the link. Beyond 40% blockage, signal loss will become significant.
This calculation is based on a flat earth. It does not take into account the curvature of the earth. It is recommended for RF path
links greater than 7 miles to have a microwave path analysis done that takes the curvature of the earth and the topography of the
terrain into account.
Fresnel Zone Radius = 72.1 SQRT [(d1d2) / (F(d1 + d2)]
Units
Fresnel Zone Radius in feet.
d1 and d2 in statue miles
F in GHz