Directional antenna for portable telephones

Advantages of the use of directional antenna patterns for portable telephones are demonstrated. They contribute to (1) reduction of power absorption into the head, (2) reduction of multipath interference, and (3) power saving and increase of battery lifetime. The paper compares directional and omni-directional antennas with the human head existing near them, in terms of radiation patterns and absorbed power. It is pointed out that overall radiation patterns are more or less directive for both types of patterns, while power absorption into the head is much smaller for directional antenna.