Research on vibration characteristic analysis and optimization design of coaxial structure in microwave source

Background The typical high power microwave generation section adopts a coaxial structure consisting of a cathode lead rod and a high frequency structure, whose coaxiality directly affects pulse width and power.

Purpose For vehicle-mounted microwave sources, vibration resistance and coaxial retention are critical for practical applications. This study aims to solve the vibration problem of the coaxial structure in microwave source.

Methods This paper establishes a dynamic model of the coaxial structure. Furthermore, the coaxial performance is analyzed under highway random vibration via simulation and experiment, and two structural improvement schemes are proposed in this paper.

Results Results show that the relative displacement of original structure reaches a maximum of 1.5mm under the excitation of the highway spectrum, which fails to meet requirements. In addition, the material improvement scheme and the conical insulation plate improvement scheme can reduce the 3σ total RMS value of relative displacement from 1.29mm to 0.141mm and 0.0144mm respectively. Therefore, both schemes can satisfy coaxiality demands under random vibration.

Conclusions The proposed methods provide a reference for microwave source coaxial structure design and improvement.