In order to test the klystrons operated at a frequency of 3.7 GHz in a continuous wave （CW） mode, a type of water load to absorb its power up to 750 kW is presented. The distilled water sealed with an RF ceramic win...In order to test the klystrons operated at a frequency of 3.7 GHz in a continuous wave （CW） mode, a type of water load to absorb its power up to 750 kW is presented. The distilled water sealed with an RF ceramic window is used as the absorbent. At a frequency range of 70 MHz, the VSWR （Voltage Standing Wave Ratio） is below 1.2, and the rise in temperature of water is about 30 ℃ at the highest power level.展开更多
In this paper, we present a design where a bunched relativistic electron beam traversing inside the rectangular dielectric-loaded （DL） waveguide is used as a high power microwave generation device. Two kinds of meth...In this paper, we present a design where a bunched relativistic electron beam traversing inside the rectangular dielectric-loaded （DL） waveguide is used as a high power microwave generation device. Two kinds of methods of calculating the electromagnetic （EM） field excited by a bunched beam are introduced, and in the second method the calculation of EM pulse length is discussed in detail. The desired operating mode is the LSM11 due to its strong interaction with the electron beam. For the designed 7.8 GHz operating frequency, with a 100 nC/bunch drive train of electron bunches separated by 0.769 ns, we find that high gradient （〉 30 MV/m） and high power （〉 160 MW） can be generated. An output coupler is also designed which is able to extract the generated power to standard waveguides with a 94% coupling efficiency.展开更多
A C-band high efficiency and high gain two-stage power amplifier based on A1GaN/GaN high electron mobility transistor （HEMT） is designed and measured in this paper. The input and output impedances for the optimum po...A C-band high efficiency and high gain two-stage power amplifier based on A1GaN/GaN high electron mobility transistor （HEMT） is designed and measured in this paper. The input and output impedances for the optimum power-added efficiency （PAE） are determined at the fundamental and 2nd harmonic frequency （f0 and 2f0）. The harmonic manipulation networks are designed both in the driver stage and the power stage which manipulate the second harmonic to a very low level within the operating frequency band. Then the inter-stage matching network and the output power combining network are calculated to achieve a low insertion loss. So the PAE and the power gain is greatly improved. In an operation frequency range of 5,4 GHz-5.8 GHz in CW mode, the amplifier delivers a maximum output power of 18.62 W, with a PAE of 55.15 % and an associated power gain of 28.7 dB, which is an outstanding performance.展开更多
文摘In order to test the klystrons operated at a frequency of 3.7 GHz in a continuous wave （CW） mode, a type of water load to absorb its power up to 750 kW is presented. The distilled water sealed with an RF ceramic window is used as the absorbent. At a frequency range of 70 MHz, the VSWR （Voltage Standing Wave Ratio） is below 1.2, and the rise in temperature of water is about 30 ℃ at the highest power level.
基金Project supported by the State Key Program of National Natural Science Foundation of China (Grant No 60532010)
文摘In this paper, we present a design where a bunched relativistic electron beam traversing inside the rectangular dielectric-loaded （DL） waveguide is used as a high power microwave generation device. Two kinds of methods of calculating the electromagnetic （EM） field excited by a bunched beam are introduced, and in the second method the calculation of EM pulse length is discussed in detail. The desired operating mode is the LSM11 due to its strong interaction with the electron beam. For the designed 7.8 GHz operating frequency, with a 100 nC/bunch drive train of electron bunches separated by 0.769 ns, we find that high gradient （〉 30 MV/m） and high power （〉 160 MW） can be generated. An output coupler is also designed which is able to extract the generated power to standard waveguides with a 94% coupling efficiency.
基金Project supported by the National Key Basic Research Program of China(Grant No.2011CBA00606)Program for New Century Excellent Talents in University,China(Grant No.NCET-12-0915)the National Natural Science Foundation of China(Grant No.61334002)
文摘A C-band high efficiency and high gain two-stage power amplifier based on A1GaN/GaN high electron mobility transistor （HEMT） is designed and measured in this paper. The input and output impedances for the optimum power-added efficiency （PAE） are determined at the fundamental and 2nd harmonic frequency （f0 and 2f0）. The harmonic manipulation networks are designed both in the driver stage and the power stage which manipulate the second harmonic to a very low level within the operating frequency band. Then the inter-stage matching network and the output power combining network are calculated to achieve a low insertion loss. So the PAE and the power gain is greatly improved. In an operation frequency range of 5,4 GHz-5.8 GHz in CW mode, the amplifier delivers a maximum output power of 18.62 W, with a PAE of 55.15 % and an associated power gain of 28.7 dB, which is an outstanding performance.
