Waveguide device, slot antenna, and radar, radar system, and wireless communication system including the slot antenna

A waveguide device comprising:

• a first electrically conductive member having a first electrically conductive surface;
• a second electrically conductive member having a second electrically conductive surface which opposes the first electrically conductive surface;
• and
• a ridge-shaped waveguide member on the second electrically conductive member, the waveguide member having an electrically conductive waveguide face which extends along the first electrically conductive surface so as to oppose the first electrically conductive surface;
• and
• a plurality of electrically conductive rods arranged on both sides of the waveguide member, each electrically conductive rod having a leading end opposing, via a gap, the first electrically conductive surface and a root connected to the second electrically conductive surface;
• wherein,
• the second electrically conductive member has a throughhole;
• the waveguide member is split by the throughhole into a first ridge and a second ridge;
• the first ridge and the second ridge each have an electrically conductive end face, the end faces opposing each other via the throughhole;
• the opposing end faces of the first and second ridges and the throughhole together define a hollow waveguide;
• the hollow waveguide is connected to a first waveguide extending between the waveguide face of the first ridge and the first electrically conductive surface, and to a second waveguide extending between the waveguide face of the second ridge and the first electrically conductive surface;
• a length of the first waveguide and a length of the second waveguide are each longer than a distance between the first electrically conductive surface and the second electrically conductive surface;
• and
• the plurality of electrically conductive rods include rods each having a width increasing toward the root.