Near field distributions around free ends of dielectric waveguide

Circular and rectangular dielectric waveguides with slanted and roof ends are studied. The near field is measured by microwave simulation. It is shown that the near field is characteristic of the shape of the free end of the waveguide. The measurement data are compared with theoretical results obtained from an approximate analysis made under an assumption about the field distribution in the waveguide cross section. This simple analysis obtains the field distribution characteristic of the end shape.