Research On Theory And Forward Design Technology Of TWTs

As one of the most influenced microwave vacuum electronic devices, traveling wave tube(TWT) has already a history of over 70 years. Because of its large bandwidth and high power output characteristics, it is widely used in telecommunications and military. And how to get a higher frequency bandwidth has been the pursuit of individual countries TWT direction. Currently, in electronic countermeasures can be achieved in three ultra-wideband coverage 2-40 GHz band traveling wave tube, among which the design of 6-18 GHz TWT is the important part.The paper mainly focuses on the study of the high efficiency of the beam-wave interaction in broadband TWT. It uses MTSS to optimize the design of the high frequency structure of a broadband helix TWT whose frequency band is between 6GHz and 18 GHz, we get a 6-18 GHz spiral broadband TWT which has gain more than 35 dB, electronic efficiency exceeding 20% and output power of more than 400 W.The main contents are as follows:1. Optimized TWT design process. The paper describes the optimized design method and process of the broadband helix TWT, and it summarizes those parameters that affect phase velocity and coupling impedance on high frequency structure.2. According to the design index of the 6-18 GHz ultra-wideband helix TWT, We use the MTSS and conventional pitch hopping interaction distribution circuit to make a 6-18 GHz broadband helix TWT which has gain more than 35 dB, electronic efficiency exceeding 20%, fluctuation of the gain more than 25 Db with non-incentives output.3. The paper proposes an inner diameter hopping technology which enables broadband traveling wave tube input and other incentives, gain ripple small. First, we use small signal theory and relative phase angle and other physical parameters of its theoretical analysis, then conclusion on the causes power saturation of sync. Finally, we come up with a method for the specific design of the inner diameter of hopping interaction.4. The paper has designed a 6-18 GHz helix TWT with the output power of over 400 W, a gain of more than 35 dB, electronic efficiency of over 20% by using MTSS along with the inner diameter hopping technology under the same incentives output. It has proven that the inner diameter hopping technology can improve the efficiency of beam-wave interaction and solve the power saturation position nsynchronous issues when designing the broadband helix TWT.5. When comparing the results including the output power and the gain using the the inner diameter hopping technology and the pitch hopping technology when designing the 6-18 GHz TWT, it has proven that the inner diameter hopping technology has its certain advantages when designing the broadband helix TWT.