Traveling-wave Klystron With Multi Operating Band

Microwave and millimeter wave vacuum devices play an important role in nationaldefense and scientific research. As one of the important vacuum electronic devices,klystron is mainly used in military electronic equipment. The rapid development ofmodern military equipment demands modification of klystron, such as broadening itsoperating band and seeking new structures which can handle high output power.Because the only operating band is easily traced, in recent years,frequency-hopping communication in military field became more important. Thefrequency-hopping communication is realized by constantly changing the carrierfrequency, and the enemy has difficulty to figure out the alteration way. Thus, thecommunications based on frequency-hopping are much safe and reliable.One-dimensional photonic crystal has features of frequency-filtering. It means thatelectromagnetic signals can transit undampedly in its pass-band. To one-dimensionalphotonic crystal which has a certain structure, the transmission coefficient can reach themaximum value of1in the pass-band we commonly call it as, while in some otherbands, the output signal will be completely reflected due to the transmission coefficientclose to0. Based on the transmission characteristics of one-dimensional photoniccrystal, this thesis will load the one-dimensional photonic crystals on both the ends ofthe rectangular waveguide which is the input cavity of the Klystron. As the photoniccrystals have multi pass-band and band gaps, the Klystron based on this structure hasthe possibility of multi operating-bands.Based on the issues and theories we mentioned above, this thesis will study on thestructure and characteristics of one-dimensional photonic crystal and traveling waveklystron. The main topics are:1. figure out an ideal structure for traveling wave Klystron by studying structureand characteristic of one-dimensional photonic crystals; the transmission characteristicsof several different structures of one-dimensional photonic crystals are compared. 2. study the influence of working bands and initial conditions to the performanceof sheet beam traveling wave Klystron, by studying the structure which has noone-dimensional photonic crystals loaded.3. put forward a new structure of traveling wave Klystron which has multioperating bands, by loading a traveling wave klystron with one-dimensional photoniccrystal.Finally, results are compared and conclusions are given.