A low-sidelobe
waveguide array antenna for a
millimeter wave vehicle-mounted
radar comprises a lower
metal layer and an upper
metal layer which are matched with each other, a first-stage E-plane
waveguide is connected with a first-stage hole
coupling power divider, the first-stage hole
coupling power divider is connected with a second-stage E-plane
waveguide, and the second-stage E-plane waveguide is connected with a second-stage hole
coupling power divider. The secondary hole coupling power divider and the secondary hole coupling cavity phase shifter are respectively and sequentially connected with the secondary E-plane waveguide through respective rectangular
cut holes and are respectively provided with a
radiation waveguide opening unit, the secondary hole coupling power divider is provided with two
radiation waveguide opening units, and the hole coupling cavity phase shifter is provided with a
radiation waveguide opening unit. Each radiation waveguide opening unit is connected with one
metal horn unit; the metal horn array is composed of a plurality of metal horn units; a
choke groove is arranged between two adjacent rows of metal horn arrays; a dummy array is arranged on one side of the metal horn array. According to the invention, a
surface wave suppression technology of
antenna isolation and
antenna gain can be considered at the same time, and a more compact and flexible-
layout mixed feed mode is adopted.