Which antenna type specifically radiates or receives energy in only two primary directions?

The bidirectional antenna is designed to specifically radiate or receive energy in two primary directions. This type of antenna focuses its energy in a linear pattern, typically covering a specific area or path in two opposite directions while rejecting signals from the sides. This functionality is crucial in applications where communication is required in two distinct areas or toward specific points with minimal interference from other directions.

In contrast, the omnidirectional antenna radiates energy uniformly in all directions in a horizontal plane, making it ideal for broadcasting signals broadly rather than in just two directions. The multidirectional antenna, while it may engage in more than two directions, does not limit itself to only two primary patterns of radiation or reception. Microwave antennas are specially designed for transmitting and receiving microwave frequency signals, and they can have various directional characteristics, but they do not specifically focus on just two primary directions as the bidirectional antenna does.