Low sidelobe level 8 mm wave band dielectric rod antenna

The invention relates to dielectric rod antennas, in particular to a low sidelobe level 8 mm wave band dielectric rod antenna. The low sidelobe level 8 mm wave band dielectric rod antenna solves the problems that an existing dielectric rod antenna is large in size, the impedance bandwidth range is small, and the sidelobe level is quite high. A first dielectric circular truncated cone section, a first dielectric cylinder section, a second dielectric circular truncated cone section, a second dielectric cylinder section and a third dielectric circular truncated cone section are sequentially connected into a whole, a conversion dielectric transition section is in a shape of a bullet, the large end of the conversion dielectric transition section is fixedly connected with the large end of the third dielectric circular truncated cone section into a whole, the outer diameter of the large end of the conversion dielectric transition section is coincident with the outer diameter of the large end of the third dielectric circular truncated cone section, a swallow-tail conic cutting section is fixedly installed on the conversion dielectric transition section in the length direction of the dielectric rod antenna and located at the tail of the dielectric rod antenna, a rectangular waveguide is fixedly installed on the conversion dielectric transition section and the swallow-tail conic cutting section in a sleeving mode in the length direction of the dielectric rod antenna, and the conversion dielectric transition section and the swallow-tail conic cutting section are located in the rectangular waveguide. The low sidelobe level 8 mm wave band dielectric rod antenna is used in a passive millimeter-wave imaging system.