Gas Leakage Analysis And Design Of Sealing Structure Of High-Power Radial Line Helical Array Antenna

High-power microwave radiation is one of the important research content of high-power microwave technology. In recent years, Domestic scholars have proposed a new type of high-power microwave radiation antenna—high-power radial line helical array antenna. Under the premise of ensuring good radiation, it has fulfilled high-power capacity, high efficiency, small size and circularly-polarized directional radiation. To achieve the power capacity requirements of high-power radial line helical array antenna, usually need to process its internal with vacuum or pneumatic. In a recent application, Inflating and sealing the antenna probe coupling region to improve the reliability of the entire antenna. Actually, taking any form of sealing treatment is difficult to achieve absolute seal. More or less, there are some leaks. Specific leakage characteristics are related with the sealing structural performance, the pressure difference, the concentration difference, the leakage area, the gas properties and other factors. Gas leakage characteristics directly determine the field strength breakdown threshold of inflatable area, effect the power capacity and efficiency of antenna. Therefore, it is necessary to study the gas leakage characteristics of the seal structure of high-power radial line helical array antenna.The gas leakage of the seal structure of high-power radial line helical array antenna occurs under the condition of leakage paths unknown. For this case, in this paper, the equivalent area method is used to replace the seal structure of the array antenna. Then, numerical simulation, theoretical analysis and experiment are used to study the gas leakage of the seal structure in the actual operating conditions. The results show that: in no pressure difference conditions, the relationship between the oxygen concentration of the array antenna and leakage time are the nonlinear, leakage port location and inside structure have a certain influence on the distribution of the oxygen concentration, the influence is more obvious in the initial stages; in pressure difference conditions, the relationship between the gas pressure of the array antenna and leakage time are the nonlinear, the pressure leaks more rapidly in the initial stage, as time increases the pressure leak more slowly, and the numerical simulation is more accurate than the theoretical analysis. Numerical simulations are consistent with the experimental trends, proving the correctness of the numerical simulation, and numerical simulation is faster, more cost-effective and can obtain internal gas parameter distribution.At last, this paper does the design and stress analysis of the seal structure of high-power radial line helical array antenna by referring the GB and related literature. And attemptting to discover a rapid method that can analyze the leakage characteristics of seal structure of array antenna that has been designed. And on the basis of conductance calculation, combined with the previous research findings, obtained the equivalent area calculation method of sealing structure that works on the no pressure conditions; on the basis of conductance calculation and leak source model, combined gas equation of state and the previous research, obtained the equivalent area calculation method of sealing structure that works on the pressure conditions. Applying the above calculation method to obtain the equivalent area, then using the equivalent area to do the numerical simulation. If the result does not satisfy the requirements, maybe considered to optimize the sealing structure. Iterating the process until the result is good, then it can obtain the reasonably designed seal structure.