| Millimeter waves are electromagnetic waves whose wavelengths are between microwave and infrared. They have very wide bandwidth and high resolution since the property of wave length. Wide bandwidth not only can increase the data capacity and the transmission capacity, but also increase the antijamming ability. It also can be used into precision tracking systems and target identification. Compared with infrared and visible light, millimeter wave can provide better transmission property in smoke and fog. While compared with microwave, it is easier to be miniaturized and can be used in the airborne radar such as missile, satellite and airplane.A great concern has been caused because of the special property of millimeter wave. But the development of millimeter wave is vey slow since there is no high power millimeter wave oscillators and amplifiers. Fortunately, after 20th century 90s, under the motivation of the military millimeter wave radar and communication the high power millimeter wave technology, especially the high power vacuum amplifier, have got a great development. The most representative devices are high power gyroamplifiers which mainly are Gyroklystron and Gyro-TWT. The other types are sheet beam klystron and TWT. They have very small structure and they are very light, but they also can provide high power. The development of gyroamplifiers and sheet beam devices have let the millimeter wave be used in radar, guidance, communication, electronic warfare, AW AC and remote sensing etc.. The development of high power millimeter wave amplifiers have great importance to consolidate national defense and the developement of national economy.In this dissertation the high power TE02 mode Gyroklystron, the 30 GHz large orbit second harmonic loss loaded gyrotwt, the electron optica and magnet of W band 74 kV pulse and 54 kV CW sheet beam klystron,220 GHz sheet beam twt had been studied innovativly.In the second chapter, the linear and nonlinear theory of Ka band high power TE02 mode Gyroklystron was studied. According to the linear theory analysis the linear gain, bandwidth and efficiency of Gyroklystron were studied. The high gain and high efficiency working state were pointed out. The bunching parameters were optimized, the higher order mode conversion was studied, the TE02 mode input coupler, bunching cavities and output cavity were designed. A nonlinear self-consistent code was developed, and has been used to optimize the resonance frequency, factor of quality and the lengths of drift sections. The large current MIG and interaction PIC model were built, the simulation gives similar results of nonlinear code. The high frequency components were made, cold test and hot test. It gave 100 kW output power in our first tube.In the third chapter, the 30 GHz large orbit second harmonic loss loaded Gyro-TWT was studied. A compact wide band TE21 mode input coupler was designed according to the ABCD matrix and HFSS simulation. The wide band pillow box input window and multi-layer output window were designed. The most important instability problem of Gyro-TWT was studied by linear theory and nonlinear theory. The start oscillate current of the most possible modes were calculated. The 3D Magic PIC simulation showed a good agreement with theory. It is the first time to show that the linear polarized TE21 mode will change to elliptical polarization. The single depressed collector and transverse output coupler were designed. The theory of CUSP gun was studied and according to this study a low beam spread and beam ripple CUSP gun was designed.In the fourth chapter, the electron optics and new PCM-QM magnet of sheet beam klystron and TWT were studied and designed. The beam transmission of 74 kV WSBK of UC Davis was increased from about 70%to 99.5%though the optimization. The hot test showed that the stable output power is 54 kW. A new PCM-QM magnet was designed for a 54 kV,10 kW W band sheet beam klystron. The room of water cooling was increased more than 80%than the old design. Besides, this new design can be adjusted in experiment for higher beam transmission. A 220 GHz sheet beam twt electron gun and magnet were designed too. The calculation showed that the transmission was higher than 97%. A CPI sheet beam gun was tested and it gave a good agreement with simulation.
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