
466 Microwave Engineering
Figure 12.42a illustrates a uctuating path traversed by a single electron
between the cathode and the anode, whereas as Figure 12.42b shows that the
electron may take several rounds before it falls into the anode.
Figure 12.43 shows the joining of a number of electrons to form bunches.
These bunches now travel in the form of spokes of a wheel in cavity mag-
netron. These spokes of bunches rotate counter-clockwise with the correct
velocity to keep up with the RF phase changes between adjoining anode
poles. Thus, a continued interchange of energy takes place with an RF eld
receiving much more energy than it gives. ...