W波段回旋行波管放大器的模拟与设计

回旋行波管放大器是高功率毫米波雷达发射系统最重要的候选者.通过对回旋行波管放大器中的绝对不稳定性、回旋返波振荡以及电子注-波互作用的研究，讨论了回旋行波管的稳定性、寄生模式的抑制和工作参数的优化等问题，给出了W波段TE₀₁模回旋行波管放大器的模拟设计结果.PIC粒子模拟结果表明，在电子注电压100kV、电流10A、工作磁场3.52T时，94GHz的基波回旋行波管放大器可获得大于250kW的输出功率、40dB的增益、大于25％的效率和约5％的带宽. 关键词： W波段 回旋行波管放大器 模拟 设计     

用于Ka波段行波管的反射式预失真线性化器

采用幂级数法分析得到了线性化器与行波管放大器相反的非线性特性,并建立了预失真放大器的幂级数模型。根据反并联二极管对电路能够产生奇次谐波的特点,利用反并联肖特基二极管对、正交混合电桥、二极管电路的匹配网络等结构,通过对各结构的分析优化,设计了用于Ka波段行波管的预失真线性化器。实验结果表明:该线性化器在29~31 GHz频段范围内能为行波管放大器的载波交调比带来最大19 dB的改善。     

S波段宽带大功率耦合腔行波管冷测实验研究

介绍了一只S波段宽带大功率耦合腔行波管的冷测实验进展.测量了该管的色散特性、同步电压、耦合阻抗等高频特性参数,测量结果与模拟值相一致.     

S波段宽带大功率耦合腔行波管冷测实验研究

介绍了一只S波段宽带大功率耦合腔行波管的冷测实验进展. 测量了该管的色散特性、同步电压、耦合阻抗等高频特性参数, 测量结果与模拟值相一致.     

X波段耦合腔行波管周期永磁聚焦系统

通过对不同耦合腔结构中电子注传输特性的研究,设计了长周期永磁聚焦系统,解决了影响电子注传输的横向磁场,开口磁环和磁场过渡区等问题,运用3维程序对X波段耦合腔行波管电子光学系统进行模拟计算,电子注通过率达到100%,波动9%,与耦合腔行波管实验要求一致。     

X波段大功率耦合腔行波管3维粒子模拟

 为提高行波管的增益和输出波形的稳定性，开展了带高频切断X波段大功率耦合腔行波管的研究工作。以点频7.2 GHz为例，对X波段耦合腔行波管的大信号注波互作用过程进行了3维粒子模拟，该行波管包含一处高频切断及两处微波集中衰减器。数值模拟结果表明：行波管腔数为40、电子束电压为17 kV、电流为0.8 A时，可获得2.0 kW的微波输出功率，增益达23 dB，电子效率达14.7%。     

Ka波段二次谐波回旋速调管放大器输入耦合器的分析与模拟

 对应用于Ka波段二次谐波回旋速调管放大器的一种输入耦合器进行了分析，并利用三维电磁模拟软件HFSS和ISFEL3D对其进行了模拟与设计。研究结果表明，该输入耦合器具有较高的能量耦合效率，并能在Ka波段获得高纯度的TE₀₂₁谐振模式。     

W波段二次谐波回旋行波管放大器的模拟与设计

回旋行波管放大器是一种具有高功率、高频率、宽带宽的毫米波放大器，TE₀₂模二次谐波回旋行波管放大器在保持基波回旋行波管放大器的基础上极大地减小了工作磁场,从而具有广阔的应用前景. 利用两段分布式损耗的互作用结构，有效抑制了绝对不稳定性和回旋返波振荡,避免了模式互作用电路引起的模式畸变，提高了输出功率，在一定程度上克服了谐波互作用较弱的缺点，满足了扩展功率容量和放大器长时间稳定工作的要求. 非线性模拟结果和粒子模型(particle in cell)模拟结果均表明，在工作电压为100k 关键词： W波段 二次谐波 回旋行波管放大器     

Ka波段宽频带行波管放大器线性化研究

线性化器是毫米波通信系统中的关键器件,在改善放大器的线性指标及提高通信质量等方面起着至关重要的作用。现阶段国内行波管放大器（TWTA）线性化技术尚不完善,无法满足通信技术发展的应用需求,因此线性化技术的研究刻不容缓。本文提出了一种新的宽频带模拟预失真线性化器结构,用来改善Ka波段TWTA的非线性特性。仿真结果表明,在26～30 GHz频率范围内,输入功率为?20～10 dBm,线性化器的增益扩张≥5.08 dB,相位扩张≥64.81 °。将线性化器与TWTA进行级联测试,中心频率的增益压缩≤3.12 dB,相位压缩≤2.31 °,三阶互调（IMD3）显著提高。     

S波段宽带大功率连续波耦合腔行波管3维模拟设计

 使用3维PIC粒子模拟软件定量分析了耦合腔行波管的大信号注波互作用行为。使用完整的仿真模型完成了S波段连续波管型的设计，达到如下设计指标：工作频率2.0~2.3 GHz，输出功率4.3 kW，频带内增益波动±0.7 dB。提出了使用大介电常数微扰介质棒减小耦合阻抗计算误差的方法，研究了行波管的冷腔特性，给出了色散、耦合阻抗等参数。     

等离子体-腔混合模耦合腔行波管非线性注-波互作用分析

 用模式展开的方法分析了等离子体-腔混合模耦合腔行波管的非线性注-波互作用过程，导出了其考虑相对论效应的非线性注-波互作用自洽工作方程组。用格林函数法求解各向异性背景等离子体（介电常数张量）下的空间电荷场。编写了计算机模拟软件，用来分析等离子体-腔混合模耦合腔行波管的增益、效率、输出功率、瞬时带宽等重要的非线性特性，计算结果表明：工作在等离子体-腔混合模式下的耦合腔行波管，瞬时带宽达到20%~30%，效率达到50%以上。     

星载X频段1600 W高幅相一致性脉冲行波管放大器

空间高分辨率合成孔径雷达(SAR)系统对大功率脉冲行波管放大器的带宽、输出脉冲能力、幅相一致性提出了更高的要求,基于宽带功率合成的k W级脉冲行波管放大器技术是空间应用的关键技术问题。研究了大功率脉冲行波管放大器宽带高幅相一致性控制技术和宽带功率合成技术,提出了空间用小型化脉冲双路合成行波管放大器集成结构,在3 GHz宽带内,实现了大于95%的合成效率,多台产品相位一致性≤±10°。     

Improving Performances and Reducing Cost for Power Amplifiers in Millimeter Wave

The high power broadband amplifiers are key devices for millimeter wave system and equipment. The significant progresses for broadband amplifier–high power TWT in MMWs are described. Advanced techniques such as enhancing operating bandwidth, reducing cost, increasing efficiency, improving heat transfer capability, suppressing spurious oscillations and raising beam transmission have been developed. These approaches possess important consult value to designer for MMW power amplifiers.     

Analysis of a Novel Ka-band Folded Waveguide Amplifier for Traveling-Wave Tubes

A novel Ka-band folded waveguide （FW） amplifier for traveling wave tubes （TWT） is investigated. The dispersion curve and interaction impedance are obtained and compared to the normal FW circuit by numerical simulation. The interaction impedance is higher than a normal circuit through the whole band. We also study the beamwave interaction in this novel circuit, and the nonlinear large-signal performance is analyzed by a 3-D particlein-cell code MAGIC3D. A much higher continuous-wave （CW） output power with a considerably shorter circuit compared to a normal circuit is predicted by our simulation. Moreover, the novel FW even has a broader 3-dB bandwidth. It therefore will be useful in designing a miniature but high-power and broadband millimeter-wave TWT.     

Engineering Computation and Analysis of Enhancing Efficiency for Folded Waveguide TWT in MMW

Large signal operating equations in TWT have been solved by numerical solve method. The relations between interaction efficiency and design parameters in TWT are analyzed. A fast engineering design method of enhancing efficiency for folded waveguide TWT by velocity resynchronization is described. The computation is shown that the efficiency of Ka-band folded waveguide TWT with double taper can be enhanced over twice as original tube. This method of approach is very useful for tube designer.     

An Open Rectangular Waveguide Grating for Millimeter-Wave Traveling-Wave Tubes

Millimeter-wave traveling-wave tube(TWT) prevails nowadays as the amplifier for radar,communication and electronic countermeasures.The rectangular waveguide grating is a promising all-metal interaction circuit for the millimeter-wave TWT with advantages of high power capacity,fine heat dissipation,scalability to smaller dimensions for shorter wavelengths,compact structure and robust performance.Compared with the traditional closed structure,the open rectangular waveguide grating(ORWG) has wider bandwidth,lower cut-off frequency,and higher machining precision for higher working frequencies due to the open transverse.It is a potential structure that can work in the millimeter wave and even Terahertz band.The rf characteristics including dispersion and interaction impedance are investigated by both theoretic calculation and software simulation.The influences of the structure parameters are also discussed and compared,and the theoretical results agree well with the simulation results.Based on the study,the ORWG will favor the design of a broadband and high-power millimeter-wave TWT.     

Preliminary Design of a Harmonic-doubling Gyrotron Traveling Wave Amplifier

This study proposes a Ka-band harmonic-doubling gyrotron traveling-wave amplifier (gyro- TWT), using distributed wall losses in the input stage and mode-selective interaction circuit in the output stage, to improve the stability of the amplification. Based on a large signal simulation code, a saturated peak power of 163 kW with an efficiency of 15.5%, a gain of 31.1 dB, and a 3 dB bandwidth of 0.9 GHz is predicted for the gyro-TWT driven by 70 kV, 15 A electron beam with a velocity ratio of 1.2 and velocity spread 5% at 33.2 GHz.     

Design of a Novel Folded Waveguide for 60-GHz Traveling-Wave Tubes

The 60-GHz traveling-wave tube(TWT) prevails nowadays as the amplifier for the satellite communication and electronic countermeasures.The folded waveguide(FW) is a promising all-metal slow-wave structure(SWS)for the 60-GHz TWT with advantages of robust performance,fine heat dissipation,considerable power and bandwidth.A novel FW periodically loaded with rectangular grooves is analyzed for the purpose of gaining higher power and gain.The rf characteristics are investigated by numerical simulation,and the nonlinear largesignal performance of such a TWT is analyzed by a 3D particle-in-cell code MAGIC.Compared with normal circuits,relatively higher continuous-wave power(40-56 W) and similar bandwidth(5 GHz) are predicted by simulation.Meanwhile,the designed operation voltage is 10.5kV,which keeps the low-voltage advantage of the popular helix TWT competitor.The novel FW will favor the design of a broadband and high-power 60-GHz TWT.     

Performance and Application of Slow Wave Circuits for Power TWT in Millimeter Wave

In millimeter wave range, high-power traveling wave tube (TWT) is a key device with broadband and high-power amplification. Basis of comparing traditional and new type slow wave circuits for high-power TWT in MMW, analysis and computation of propagating and RF performance for folded wave circuit are carried out. Theoretic calculation and experimental test show that folded wave circuit is an ideal slow wave structure for broadband and high-power TWT in MMW. There is extreme wide application for the circuit in high-power TWT. This development possesses important consult value to designer for MMW power amplifiers.