Xiaobao Su

The Education, Research and Development of Microwave Electronics and Microwave Tubes in China

The paper gives an overview of the education and research and development of microwave electronics and microwave tube in China. A brief historic account of these technologies is also provided.

A Multi-Objective Genetic Algorithm for Optimizing Dispersion and Coupling Impedance in Helix TWTs

Optimization techniques have been used in traveling wave tubes design for the slow-wave circuit phase velocity taper and collector stages (Wilson, 2001; Chevalier et al., 2003). In the slow-wave circuit design, the objective function aims to minimize the difference between dispersions versus different frequency, and maximize the on-axis interaction impedance in a specified bandwidth. This is a double-objective optimizing problem. Unfortunately, the objective functions are conflicting. The small difference between dispersions comes with the decrease of interaction impedance. The single-objective optimization, therefore, is not suitable to pose this problem. However, to our knowledge, these multi-objective optimization techniques have not been applied to general slow-wave circuit design until now. The expression of evaluating interaction impedance in the sheath helix model was also presented

4.5: Recent results on a X-band 70W space traveling wave tube

X band TWT usually is used for satellite based data transmitting systems. Institute of electronics, Chinese academy of sciences has developed high efficiency X band space traveling wave tubes(TWT) with CW output power 70 watts.

Influence of interface status on heat dissipation capability of collector for travelling wave tube

In the paper, Influence of interface status (ratio of brazing area and fit clearance) of brazed collector parts on contact heat resistance was theoretically analysised. And by ANSYS simulation, influence of ratio of brazing area and fit clearance on heat dissipation capability of collector for travelling wave tube was studied.

High power and efficiency power combining of space TWTAs with waveguide magic-T for Satellite communication

A high efficiency power combining demonstration is presented in this paper of 2 X-band TWTAs based on magic-T corporate combiner. A low loss, amplitude and phase balanced, high isolation and power waveguide magic-T combiner is designed. Power combining efficiencies of greater than 90% and output power of more than 85W over a 0.7GHz frequency band are successfully demonstrated by introducing phase shifter and variable attenuator within input end. Such combiner can also be taken as an element within a corporate combining architecture of more TWTAs for much high efficiency and power outputting for satellite communication.

A simple sample-and-hold circuit for TWT power detecting

A simple sample and hold circuit for 6-18GHz TWT power detecting is proposed in this paper. This circuit has a simple circuit structure and long holding time. Through a combined test with TWT, the efficacy of the circuit is validated.

P1–32: Thermal analysis of the gridded electron-gun

ANSYS, the finite-element analysis software, is used to simulate the temperature field in steady state and the thermal deformation of the gridded electron gun. The temperature distribution characteristic of the grids are shown here. TWTCAD is used to calculate the performance variation of the electron optics under the thermal deformation which is showed.