Mechanical antenna downtilt and its impact on system design

Abstract

Mechanical antenna downtilting has been an effective way to reduce interference by confining the signal in its own coverage cell. It can reduce co-channel interference significantly when a notch is developed in the direction of the co-channel cell. We define the condition for the antenna pattern to develop a notch and discuss the impact of downtilt on the system design. We also introduce the concept of significant and optimal notch. Computer simulation of different antenna patterns is done to illustrate the notch developing process.