Study On The Novel Slow-wave Structures For V-band Traveling-wave Tube

As an important atmospheric attenuation window, the V-band has been shown great potential on both military and civil areas. At present, the development and utilization of this band in our county lags relatively behind compared with USA, Japan and Europe. In order to meet the requirement of complex military communication and information countermeasure, and to further improve the theory and key technology level on millimeter-wave vacuum electronics, researches on this band are of great significance in both theory and practice. The dissertation is based on the V-band traveling-wave tube and puts emphasis on the research of two kinds of novel all-metal slow-wave structures. And the application potentials of these structures in V-band traveling-wave tube are analyzed. The main work and innovations of this dissertation are as follows:1. The folded waveguide slow-wave structure is employed to design the V-band CW traveling-wave tube, including the slow-wave structure, the interaction circuit, the high-frequency coupling structure and the magnetic focusing system, etc. And the experimental study on the V-band traveling-wave tube is conducted firstly in domestic.2. In order to improve the output power of the folded waveguide traveling-wave tube, a novel sheet beam folded waveguide is proposed. And design of the V-band high-power traveling-wave tube is completed by employing this structure and sheet electron beam as the interaction circuit. From the research results, it can greatly increase the interaction area by adopting the sheet electron beam, which can acquire more output power without increasing the current density. Meanwhile, it has little effect on the bandwidth and electron efficiency of the tube if proper size of the beam channel is chosen. Therefore, it provides a good idea for the development of V-band high-power traveling-wave tube.3. A novel wideband high-power slow-wave structure called V-shape folded rectangular groove is proposed innovatively, and the interaction circuit for the V-band traveling-wave tube is designed by employing this structure. The research results show that it can increase the interaction area without variation of good working performance, which can adopt the sheet electron beam with larger area to acquire more output power. Meanwhile, it is a typical two-dimensional structure and don’t need to machining the beam tunnel, which can be fabricated and assembled easily. Therefore, as a very potential wideband high-power millimeter-wave structure, the V-shape folded rectangular groove waveguide will play a positive role in the development of wideband high-power millimeter-wave radiation sources.4. In order to solve the energy coupling problem between external circuit and the reentrant double staggered ladder line coupled-cavity slow-wave structure, a well-matched input and output coupler is proposed. And design of a100watts V-band coupled-cavity traveling-wave tube is completed by employing this structure. Compared with the folded waveguide traveling-wave tube, it has more output power and higher electron efficiency under the condition of the basiclly same voltage. And the working bandwidth of the tube can be expanded to the same level of the folded waveguide travel ing-wave tube by tuning the beam voltage. Therefore, it provides another optimal scheme for the development of V-band high-power traveling-wave tube.5. A well-matched input and output coupler is proposed for the three slot ladder line coupled-cavity slow-wave structure, and the interaction circuit for the V-band traveling-wave tube is designed by employing this structure and a5:1aspect-ratio sheet electron beam. From our calculations, when the cathode voltage and beam current are set to13.2kV and300mA, the three slot ladder line coupled-cavity traveling-wave tube can produce saturated output power of over320watts, the corresponding saturated gain and electron efficiency can reach over32.56dB and8%, respectively. This structure provides a good scheme for the development of V-band wideband high-power traveling-wave tube.