WAVEGUIDE HORN ANTENNA, ANTENNA DEVICE, AND RADAR DEVICE

摘要

A waveguide horn antenna comprising, formed on a conductor member (2), a feed waveguide (3) and a radiating waveguide (1) having a radiation direction perpendicular to the electromagnetic wave propagation direction of this feed waveguide (3). The radiating waveguide (1) comprises a horn type waveguide (12) consisting of a tapered waveguide opening to the outside from the conductor member (2) and having its sectional area gradually increasing toward the opening, and a logarithmic spiral waveguide (11) that connects the horn type waveguide (12) with the feed waveguide (3) and has a shape of extending in a 270æ rotation from the connection surface with the feed waveguide (3) up to the connection surface with the horn type waveguide (12) while surrounding the circumference of the feed waveguide (3). The logarithmic spiral waveguide (11) has its side wall formed in a logarithmic spiral shape when viewed from a plane direction perpendicular to the signal propagation direction of the feed waveguide (3) and is formed in a shape of linearly extending in the signal propagation direction of the feed waveguide (3).