The Design And Realization Of Ultra-wideband Miniaturized TWT Slow-wave Circuit

Ultra-wideband miniaturized TWT with large bandwidth, small size, high efficiency and low operating voltage advantages. At present, this ultra-wideband continuous wave traveling wave tube has a clear demand, but domestic in the ultrawideband continuous wave traveling wave tube technology research and abroad, there is a big gap. Therefore, the ultra-wideband miniaturized TWT research has important practical significance.Ultra-wideband helix slow-wave circuit design is the development of ultra-wideband miniaturized TWT focus. For the slow-wave circuit characteristics and technical difficulties, the paper miniaturized ultra-wideband TWT slow-wave circuit is analyzed theoretically, using three-dimensional high-frequency calculation program MAFIA and Ukraine 2.5D large-signal process HFA slow for three kinds of ultra-wideband wave circuit simulation calculations to determine the slow-wave circuit UWB initial program. Then parameters were optimized, taking into account the key components process control, complete ultra-wideband miniaturized TWT slow-wave circuit development.This paper mainly works includes:1, a typical broadband helical slow-wave circuit structure were analyzed and compared to determine the T- shaped clamping lever loaded slow wave circuit structure, and to determine the composition of the material slow-wave circuit, comprising: a narrow strip of molybdenum with spiral, boron nitride clamping lever, diffuse oxygen-free copper shell and tube loading.2, the use of three-dimensional high-frequency calculation program MAFIA and Ukraine 2.5D large-signal process HFA, computing load in the form of typical broadband slow-wave structure, analysis and comparison of its dispersion characteristics, coupling impedance. And the simulation results into 776 factory independent research program into the calculation of large-signal and coupling assembly according to the input impedance matching can experience worthy of their situation and the correction value to determine T-shaped ridge head support rod clamp load variable pitch slow-wave circuit basic scheme.3, on the slow-wave circuit structure of the basic details of the key program simulation and optimization, including the T-shaped clamping rod size, precision loaded shell and tube inner diameter, helix transition phase velocity results, to be consistent with the simulation results and theoretical analysis, the comprehensive consideration harmonic suppression situation, and ultimately determine all of the circuit parameters.4, in order to ensure to meet the design target values of key parts of the manufacturing process and assembly process control.5, for ultra-wideband miniaturized TWT slow-wave circuit tubing series of environmental assessment test test done on the parameters of the traveling wave tube test.After testing, the use of slow-wave circuit designed in this paper miniaturized ultra-wideband TWT at 4.5-18 GHz band output power Pout ≥ 45 W, gain G ≥ 31 dB, the second harmonic ratio ≤-2.3dBc. Test results show that the slow-wave circuitdesign fully achieve the desired design goals.