
406 Microwave Engineering
is thus to result in current-density-modulated beam that varies at the same
rate as the grid-signal frequency. Thus, a useful power from the beam can be
extracted. Figure 11.16a and b illustrates the current-modulated (bunched)
electron beam in various stages of formation and dispersion.
11.4.2.3 Energy Extraction
As shown in Figure 11.16, a second cavity, called a catcher cavity is placed
at a point of maximum bunching to take useful energy out from the beam.
The physical location of this cavity is determined by the frequency of the
buncher-grid signal as this signal determines the transit time of the electron
bunc