Research Of 140GHZ Sheet Beam Extended Interaction Oscillator

Terahertz wave has high working bandwidth,good beam directivity,anti-interference and other physical characteristics.It is widely used in many cutting-edge fields,such as 6G communication,ultrafast computing,satellite relay,homeland security and so on.At present,with the rapid development of terahertz technology,the generation and transmission of system power has become the focus of design.As the core device of the system,the output power level of terahertz source directly determines the operation efficiency of the whole system.Therefore,strip electron beam device,as an important method to effectively improve power at high frequency,came into being,and has been regarded as the research frontier in the field of electronic vacuum devices.The combination of banded electron beam and extended interaction oscillator not only solves the problem of large characteristic impedance caused by multi gap high-frequency structure,but also matches the problem of small length of interaction circuit caused by small size of high-frequency extended interaction device,The banded beam can be transmitted in a small high-frequency gap,and the effective beam wave interaction can be carried out under the action of magnetic focusing magnetic field.This thesis is mainly a series of researches on the 140GHz band-beam extended interaction oscillator.The research content mainly includes the research on the high-frequency structure of the 140GHz band-beam extended interaction oscillator,the particle simulation for optimizing the operating point,and the design including the square-circle transition and the circular waveguide radius to further improve the power capacity and perform better power output.The gradual EIO output system,the specific research content is as follows:1.Research and simulate the cold cavity characteristics of the high-frequency structure of the model.Through the analysis of synchronization conditions,dispersion characteristics and electric field distribution characteristics,it is determined that the 2?mode of TM₁₁ is selected as the working mode of the extended interaction cavity in this thesis,and then It can effectively avoid the problem of mode competition,maintain the stable operation of single mode and reduce the complexity of processing.2.Study the effect of particle simulation and high-frequency structures,and the variables are debugged to continuously optimize the simulation results.By analyzing the particle simulation situation under the theoretical working voltage,the electrons do not have effective high-frequency interaction.In order to achieve effective injection-wave interaction under the existing device structure,a single variable is used for the electron injection voltage,current,focusing magnetic field strength and output port position.Debug and then optimize the injection-wave interaction effect to obtain the best output power,the least electronic interception and the efficient injection-wave interaction effect.3.In order to improve the power capacity,an EIO output system combining transition waveguide mode conversion and sapphire sealing window is designed,and the transition waveguide mode converter is simulated and calculated by using the coupled wave theory and the coupled wave equation of the radius circular waveguide,including the mode conversion efficiency.And the transmission efficiency enables very efficient mode conversion and coupling inside the waveguide,improving the energy conversion efficiency,so that the energy can be concentrated on the axis as much as possible.