Sector antenna apparatus and vehicle-mounted transmission and reception apparatus

摘要

The apparatus (1) has a horn antennas for radiating high-frequency signal beams (B) in different directions, and an antenna changeover switch for switching between the horn antennas. The first horn antenna emits beam radiation in a high-angular-resolution direction, and has a larger aperture providing a narrow beam width. The second horn antenna emits beam radiation in a low-angular-resolution direction, and has a small aperture providing a broad beam width. An independent claim is also included for the vehicle-mounted transceiver comprising the sector antenna apparatus.