Figure 1-13.E field of a voltage standing wave across a
1-wavelength section of a waveguide.
H FIELD.The magnetic field in a
waveguide is made up of magnetic lines of force that are caused
by current flow through the conductive
material of the waveguide. Magnetic lines of force, called H lines,
are continuous closed loops, as shown in figure
1-14. All of the H lines associated with current are
collectively called a magnetic field or H field. The
strength of the H field, indicated by the number of H
lines in a given area, varies directly with the amount
Figure 1-14.Magnetic field on a
single wire. Although H lines
encircle a single, straight wire, they behave differently when the wire is
formed into a coil, as shown in figure
1-15. In a coil the individual H lines tend to form around each turn of wire.
Since the H lines take opposite
directions between adjacent turns, the field between the turns is cancelled.
Inside and outside the coil, where the
direction of each H field is the same, the fields join and form
continuous H lines around the entire coil.