Broadband millimeter wave four-ridge horn probe

The invention discloses a broadband millimeter wave four-ridge horn probe which mainly solves the problems that an existing high-frequency probe is narrow in bandwidth and poor in directional diagram symmetry. The loudspeaker comprises a loudspeaker shell (1), four ridge pieces (2), a waveguide back cavity (4), two coaxial probes (5) and a short circuit plate (8), the ridge pieces are fixed in the waveguide back cavity, the two coaxial probes penetrate through air cavities of a first ridge piece and a second ridge piece respectively and stretch into a third ridge piece and a fourth ridge piece which correspond to each other, orthogonally staggered placement of the two coaxial probes is formed, and the short circuit plate (8) is fixed on the waveguide back cavity. A square structure is adopted at the open circuit position of the loudspeaker shell, and a plurality of gaps (6) with unequal adjacent intervals are formed in the loudspeaker wall. The ridges, close to the arc portions, of the four ridge pieces are p