Xingqun Zhao

Research on traveling wave tube body temperature distribution

The paper describes simulation result of traveling wave tube(TWT) body temperature, and establishes a temperature measurement system based on the fiber bragg grating(FBG) sensor array. By quasi-distributed FBG sensing, the system can measure TWT body temperature distribution accurately.

Electromagnetic band gap substrate for planar microstrip meander line travelling wave tube

Novel dual-square electromagnetic band gap (EBG) substrate is investigated to improve the performance of planar microstrip meander line travelling-wave tube (MML-TWT). According to the simulation results, this EBG structure can improve coupling impedance double and extend bandwidth from 9.5GHz to 10.5GHz. This structure also can be fabricated in one-dimensional for the MML-TWT. In other words, it has same transverse dimension of MML-TWT, which is important to fabricate the planar travelling wave tube.

Measurement experiment of residual gas inside vacuum electronic devices based on Rayleigh scattering

We performed an experiment demonstration for verifying the measurement method based on Rayleigh scattering to test the residual gas in a storing vacuum electronic devices (VED), using high pulse power ultraviolet laser and CCD detector. The normalized intensities of scattered light are obtained before and after degassing the test tube. The experimental results validate the measurement method we proposed before.

Testing-based estimation method for inner temperature distribution of TWT collector and output terminal

A testing-based estimation method for inner temperature distribution of collector and output terminal is proposed without placing temperature sensors inside the traveling wave tube. The inner temperature distribution is estimated based on testing body temperatures, with an iteration solving the thermodynamic parameters of the thermal model. The results indicated that the method has good feasibility and accuracy.

Performance degradation simulation for M-type cathode based on ion bombardment

Simulation of M-type cathode performance degradation is studied based on ion bombardment with interdiffusion effect considered. Sputtered volume, sputter distribution and ion spot occurrence time can be estimated, with estimated sputtered volume close to former researches. For M-type Re-coated cathode with 300nm-thick film, ion spots were estimated to appear after 2.06×105 hs working.

Temperature dynamic response of slow-wave structure of space traveling wave tube

The thermal condition of slow-wave structure is very important to the normal and stable work of the space traveling wave tube. This paper theoretically analyzes dynamic response of helical slow-wave structure, and simulates it with the help of ANSYS., The dynamic response of temperature under different pulse duration and duty cycle is acquired through analysis and simulation.

P4-18: Cold testing platform for Electromagnetic Band Gap waveguide

A high space resolution platform has been built to measure the cold test parameters of Electromagnetic Band Gap (EBG) waveguide. The space resolution of this platform can be reached to 4µm and controlled by FPGA and computer through LABVIEW. An EBG waveguide is fabricated for measurement. The mode field of cross section and propagate constants have been simulated by our coding and tested by this platform‥

Microstrip Meander-Line Slow Wave Structure Based on Electromagnetic Band Gap Surface

An Electromagnetic Band Gap Structures (EBGS) has been used in the Microstrip Meander-Line Slow Wave Structures (MML-SWSs) in order to improve their performance. The EBGSs can be used as the substrates to support the MML-SWSs, which replace the ceramic substrates in traditional ones. The simulation results show that the minimum loss of the MML-SWSs used EBGS is half of the traditional one.