Thermal Deformation Of The Performance Parameters Of The Helix Traveling Wave Tube

With the development of vacuum electronic technology, the requirement for the performance of Traveling-Wave Tube (TWT) from military electronic industry and commercial use becomes much higher. TWT plays an important role as high power and wide band microwave generator and microwave amplifier. The higher requirement for TWT is also being promoted by modern satellite communication, space communication, phase array radar etc., from the aspect of smaller size, longer age, higher reliability and so on.The working frequency of TWT is very high, thus, the size of TWT slow-wave structure is very fine. This brought much difficulty for the design. Nowadays, more and more computer simulation technology is brought into TWT design work for saving cost and improving design efficiency. It can be applied in each link of TWT design work. The main work of this thesis is simulation of the thermal characteristic, the thermal distortion and cold test characteristic for helical TWT slow wave structure with ANSYS, which is a finite element software. Then the redevelopment upon this software was performed.The relative theory basis of thermal calculation was shown. Then the details of simulating the thermal characteristic of TWT slow-wave structure with ANSYS were given. The results from theoretical calculation, experiment and stimulation are consistent and this proves it is acceptable to apply ANSYS Code to the thermal analysis of helical TWT slow structure. The result of thermal analysis for helical slow-wave structure had been achieved in the form of temperature contour figure and heat flow density vector figure. This result implied the temperature distribution clearly and could be used for analyzing the reliability of TWT and its improvement. So the higher output power can be achieved. On the basis of thermal analysis, the method with the coupled analysis of thermal-structure in ANSYS is introduced. The result of thermal distortion is got. The theory and calculation way about the dispersion and interaction impedance characteristic are listed in detail. Applying the CSTMWS and ANSYS to simulate the dispersion and interaction impedance and the difference between them is analyzed. Using the nodes'coordinates to update the element model, the eigenfrequency of the thermal distortion of slow structure is solved in ANSYS code. The data from the same platform is comparable and it is useful for the TWT's designer to compete the thermal design.The special software used for helical TWT slow structure thermal analysis was made base on the ANSYS simulation. This software is simple to manipulate and can provide enough precision. Therefore, it is a convenient tool for TWT designer, giving them more design efficiency and saving cost.