| In recent years,research has been intensely focused on millimeter wave technology.In the field of wireless communication,the high-band millimeter wave,W-band(75-110GHz)can provide greater transmission bandwidth and communication capacity than the low-frequency band.In addition,due to its strong penetrating ability,millimeter waves can penetrate cloud layer to achieve all-weather communication.Therefore,it is of great military and economic significance to research and develop high-performance and highpower millimeter-wave signal sources.As the most widely used vacuum electronic device in the millimeter wave band,traveling wave tubes(TWT)have the power capacity of large amounts,the wide operating bandwidth,and the capacity to adjust to varying environments,and the output power in the millimeter wave frequency range is much greater than that of solid-state devices.The beam-wave interaction in slow-wave structure,under vacuum conditions,is the mechanism of action that enables the signal to be amplified.High power output,which is conducive to enhancing the overall performance of the satellite communication system,can be achieved by research on the millimeter-wave TWT as a satellite communication uplink RF front-end device,with a solid-state device as the front-stage input.Research on continuous wave TWT working in the W band has high application value.This thesis designs a continuous wave TWT with a folded waveguide as a slow wave structure,which has a working frequency range of 91-97 GHz.The gain of the TWT reaches more than 30 d B,and the saturated output power exceeds 100 W.The main work as follows:1.The electron gun and periodic permanent magnet(PPM)focusing system were designed from theoretical calculation and software simulation;then assembling electron optical system and electron channel tube to test the emission current of the electron gun,and the electron optical system meeting the requirements was verified.2.Based on the equivalent circuit theory,the dispersion,coupling impedance and loss characteristics of the folded waveguide slow-wave structure are investigated by using HFSS.Next,according to the experimental results of the electron optical system;use FWGTWT software to calculate the beam-wave interaction,design a 100 W output scheme,and then use CST software to verify the design;on the basis of the 100 W design scheme,there is a design A high-voltage solution was proposed,and the efficiency was improved through phase velocity shifted to achieve 200 W output.3.The transmission system of the TWT is designed.Transitional waveguide,attenuator and energy transfer window use HFSS to analyze the structural parameters and simulate the transmission characteristics to meet the requirements of use.4.Process the components of the traveling wave tube and assemble them;use a vector network analyzer to test its transmission characteristics;build test platform to debug the electron transmit rate of TWT,and then test the saturated output power and gain,record results and analysis. |
