| High-power klystron occupies an important position at the microwave tube. Because of the great output power, high gain, long-life, high-stability characteristics, it has obtained a wide range of applications in radar, communications, high-energy particle accelerators and industrial heating, et al.Broadband, high power, high efficiency is the development trend of the klystron amplifier, and double-gap coupled-cavity as a show band, enhance efficiency, improve peak power and average power effective means has been widely used in multi-beam klystron and high-power klystron, use of the double-gap coupled-cavity can improve the R/Q of the klystron output gap and increase the output bandwidth to 1.5-2 times. Secondly, by reducing the voltage of single gap and the loss of power of per unit wall, it can improve the klystron peak power and average power capacity. In addition, use of the double-gap coupled-cavity can improve the electron interaction with the high-frequency field of klystron output gap and improve the efficiency.Although high-power klystron with the merits of the above, its development cycle and costs also quite surprising, therefore, in order to shorten the development cycle, reduce costs and improve the performance of the devices, the use of computer-aided design (CAD) is more and more widely, at present, almost all the design of new developed klystrons would be helped by CAD technology. The design of multi-beam klystron (MBK) can be seen as a example of application of CAD. Currently several commercial software has been used for the design of SBK and MBK, such as MAFIA, MAGIC, HFSS and ANSYS. More important, particle simulation (PIC) also can be analyzed by MAGIC and MAFIA. Unfortunately, in our country we have no independent intellectual property rights in klystron analysis software.Beam-wave interaction analysis and calculation of vacuum electron devices is an important part of CAD software, because just in this stage, electronic kinetic energy released, and the energy can be transformed into the microwave energy. But today most of the researches on klystron with double-gap output cavity were use of the existing simulation software, it always needs long time, in order to study the beam-wave interaction process of klystron especially in the double-gap output cavity, we present a single period , one dimensional time integral model development a rapid analysis procedures. Use the procedure we calculated the electronic-cluster graphics, it shows that the calculated results and the MGAIC results are in good agreement. Because this procedure needs a short time to operation, we also study the influence of the parameters of the beam-wave interaction.Several important and valuable results are achieved and listed as follows:1. Using CST software analysis the electromagnetic field of a single gap and double-gap resonator, and have derived the solution of double-gap coupled-cavity's gap impedance and the impact of its resonant frequency by the size of coupling joints2. In one-dimensional theoretical analysis, we present a single period, one dimensional time integral model development a rapid analysis procedure of double-gap output cavity klystron, and only considered the electronic disc's axial movement, all procedures based on the principle of time integral.3. In two-dimensional theoretical analysis, this paper started with klystrons'radial and axial interaction equations with the use of limited thickness of the electronic ring model and will deal with the process of beam-wave interaction based on the principle of time integral, and the main innovation of this article is the analysis of double-gap output cavity's beam-wave interaction.4. To as an example of a S-band klystron for a detailed numerical analysis, and compared with the results of related documentation and the MAGIC procedures and results showed that: programs are basically consistent with the actual situation. |
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