Microwave heating device

A microwave heating device comprising:

• a heating chamber configured to accommodate a heating target object;
• a microwave generator including a substrate, the microwave generator being configured to generate a microwave onto the substrate;
• a waveguide mounted with the microwave generator;
• and
• a coaxial connector including a center conductor, an insulator, an external conductor, and a positioning member,
• wherein:
• one end of the waveguide is connected to the heating chamber;
• the center conductor is a single conductor including a first end and a second end, the first end being connected to the substrate of the microwave generator and the second end projecting into the waveguide;
• the first end of the center conductor is closer to the microwave generator;
• the second end of the center conductor is closer to the waveguide;
• an air gap is defined between the center conductor and the insulator;
• the positioning member includes a first flange, a second flange, and a third flange;
• the first flange projects from a first part of a surface of the insulator and contacts a first part of the center conductor;
• the second flange projects from a second part of the surface of the insulator and contacts a second part of the center conductor;
• the third flange projects from a third part of the surface of the insulator and contacts a third part of the center conductor;
• and
• the air gap includes:
• (i) a first space between the first flange and the second flange;
• and (ii) a second space between the second flange and the third flange.