Microwave and Wireless Communications Technology

Summery 225

2. In an M-type

magnetron, the

electron beam travels in a circular path, shock

exciting a series of resonant cavities. The RF wave set up across the entrances to the

cavities interacts with the electron beam to force the electron cloud into a charac-

teristic rotating spoked-wheel shape. As the spokes of this wheel sweep past the res-

onant cavities, they further shock excite the cavities into self-oscillation, causing the

oscillation to be sustained. A coupling loop or waveguide slot is used to extract RF

power from the magnetron.

3. The crossed-field amplifier (CFA) is a magnetronlike device that uses

crossed electric ...