One of the significant and practical applications in the field of condensed energy physics is the generation of the microwave by the electronic emission from a cathode in a vacuum tube, and in turn collimating and directing the electron beam by the aid of an electric or magnetic field. The most well-known technique for performing it, is the thermionic or cold method depending upon the vacuum tube, and the wanted microwave power. The wavelength of these waves usually lies between 1 mm to 1 m or in the frequency interval of 3 till 300 GHz. The close correspondence between microwave engineering, especially in high powers, and plasma physics has caused that most of the simulations can be utilized in both domain commonly. PIC and FDTD techniques, and Mote Carlo method for designing vacuum tube, are the common backgrounds.
s a matter of fact, practical microwave systems consists of a microwave generator like vacuum tube, and a distributor like antenna. Therefore, each of these components should be study separately. On account of some differences in design, analysis and simulation, we’d better survey each of them in detail.
