directive antenna

electronics

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 25, 2026

Quick Summary

A directive antenna is an electronic component that radiates or receives signals more effectively in certain directions than in others. This directional capability is crucial in technologies like radar, where a narrow beam of electromagnetic energy is transmitted into space.12

In radar systems, a directive antenna focuses energy in a specific direction to scan for targets. When a target is hit by this beam, it reflects some energy back to the radar system. The antenna then receives this reflected signal, allowing the system to determine the target's range and angular direction. The precision of these measurements depends on the antenna's ability to direct its energy narrowly. For instance, tracking radars use a "pencil" beam for precise target location, while surveillance radars might use a "fan" beam that is narrow in one direction but broad in another.2

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

radar
Directive antennas and target direction
Almost all radars use a directive antenna—i.e., one that directs its energy in a narrow beam. (The beamwidth of an antenna of fixed size is inversely proportional to the radar frequency.) The direction of a target can be found from the direction in which the antenna is pointing when the…
Read More
Almost all radars use a directive antenna—i.e., one that directs its energy in a narrow beam. (The beamwidth of an antenna of fixed size is inversely proportional to the radar frequency.) The direction of a target can be found from the direction in which the antenna is pointing when the…
Read More