Connection structure of waveguide, waveguide connector, mode converter, and waveguide unit

A connection structure of a waveguide, the connection structure connecting a waveguide used for transmitting a radio wave of a millimeter wave frequency or a frequency higher than the millimeter wave frequency, to another member, wherein

• the waveguide includes
• a rod-like dielectric, and
• an outer conductor formed by braiding a plurality of flat foil yarns into a braid shape around the rod-like dielectric, the plurality of flat foil yarns having conductivity,
• a three-dimensional component, which is the other member, includes
• a connection surface at least partially including a conductive region to which a connection enlarged portion of the outer conductor is connected in a state where the three-dimensional component is connected with the waveguide,
• an insertion hole which is open on the connection surface, and has conductivity over an entire circumference of an inner surface, a portion of the rod-like dielectric exposed at the connection enlarged portion of the waveguide being inserted into the insertion hole in the state where the three-dimensional component is connected with the waveguide, and
• a corner which forms an opening edge of the insertion hole over an entire circumference on the connection surface, the corner having conductivity and being conducted with the inner surface of the insertion hole, and
• in a state where the waveguide and the other member are connected with each other, the connection enlarged portion is electrically conducted with the inner surface of the insertion hole through electrical connection with the connection surface and the corner, and smooth connection is made at the corner.