Caiying Wang

Research Progress on C -band Broadband Multibeam Klystron

Several types of C-band broadband multibeam klystrons (MBKs) are under development at the Institute of Electronics, Chinese Academy of Sciences. These MBKs operate at various C-band frequencies and have peak powers of 30-200 kW, average powers of 2-10 kW, and bandwidths of 4%-7%. The design considerations for obtaining high power and wide instantaneous bandwidths and test results for these MBKs are presented in this paper. The main technical problems, including a power sag in the band, high voltage breakdown, and non-operating mode oscillation, are also discussed. Further research work for improving the performance of these MBKs is described

Research Progress on X-Band Multibeam Klystron

The Institute of Electronics, Chinese Academy of Sciences, started developing X-band multibeam klystrons (MBKs) in 2000. Three types of X-band MBKs are currently under research and development; two types operate in the fundamental mode (TM010), and the other type operates in a high-order mode (coaxial TM310). These MBKs operate over the frequency range from 8 to 10 GHz and have peak powers of 50-100 kW, average powers of 2.5-5 kW, and bandwidths of 5%. The design considerations and testing results are presented in this paper. The technological problems, including nonhomogeneity of the RF electric field and low beam transmission, are also described. Further research work on the improvement of these MBKs is discussed.

Research Progress on C-band Broadband Multi-Beam Klystron

Several types of C-band broadband multi-beam klystron (MBK) are currently developing at the Institute of Electronics, Chinese Academy of Sciences (IECAS). These MBKs operate on the frequency range from low end to high end of C-band, and have peak power of 30-200kW, average power of 2-10kW, bandwidth of 4-7%. Careful design and experimental adjustment of the focusing system is very important for raising the DC beam transmission above 90% for C-band MBK with average power of 10kW. Experimental power-frequency characteristics for KC4079L are shown. There is good consistence between them. But there is some difference between the calculated and experimental gain-frequency characteristics

The Recent Research Progress on L-band 100 kW CW Broadband Multi-Beam Klystron

L-band 100 kW CW Broadband Multi-Beam Klystron with bandwidth of 12% is currently being developed at the Institute of Electronics, Chinese Academy of Sciences (IECAS) (Ding et al., 2003). The main technical difficulties for this MBK as shown in this paper are instability and oscillation of parasitic modes in CW state. In past two years, six tubes have been manufactured and tested. The test results and the technical problem met in these tubes will be described in this paper.

Progress of an S-band high average power broadband multi-beam klystron

An S-band high average power MBK producing peak power of 500kW and average power of 30 kW over 10% of relative bandwidth has been designed in Institute of Electronics, Chinese Academy of Sciences (IECAS). Two klystrons are manufactured and have been well tested. Fundamental mode was chosen for RF interaction system, and both calculation and experimental results will also be addressed in this paper.

Research and Development of S-Band High Power Multibeam Klystron

The design, manufacture, and test of an S-band high power multibeam klystron (MBK) are presented in this paper. The test results indicate that the performance of the MBK satisfies the design requirement. Several technical problems, such as the oscillation of high-order modes, a decrease of the beam current under no-driver (oscillating) conditions, and the high-voltage breakdown are also discussed. Some improvements have been taken to overcome these problems. The improved tube has a beam transmission rate over 98%, and operates very stably under DC and RF conditions.

Development of an S-Band High Average Power Multibeam Klystron With Bandwidth of 10%

An S-band high average power multibeam klystron (MBK) producing peak power of 500 kW and average power of 30 kW over 10% of relative simultaneous bandwidth has been designed and developed in Institute of Electronics, Chinese Academy of Sciences (IECAS). The biggest challenges were achieving over 10% relative simultaneous bandwidth performance with higher efficiency at the same time and focusing and transport of the intense electron beam because of the highest level average power in all types of MBKs in IECAS. Two prototypes were manufactured and both have been thoroughly tested. The fundamental mode was chosen for the RF interaction system, 24 beams are used to obtain a beam current of 50 A and the beam voltage is 29 kV. The efficiency is greater than 40% and the gain is greater than 37.5 dB over a relative simultaneous bandwidth of 10%. Both design considerations and experimental results have been addressed in this paper. The experimental results are close to design specifications.

The design of S-band 1.5MW high power multi-beam klystron

A new type of S-band multi-beam klystron (MBK) with peak power of 1.5MW is developing at IECAS. The design of the electron optics system, RF interaction section and broadband output coupling systems of the MBK will be described in this paper. Also some cold measurement results of the tube will be presented.

Development of C-band CW broadband klystron

The design of the electron optics system, RF interaction section and broadband output coupling systems of the klystron will be described in this paper.