S波段大功率注入锁频磁控管的输出特性

在多路注入锁频大功率连续波磁控管的相干功率合成实验中,输出特性分析有利于提升合成效率。搭建了一款S波段20 kW连续波磁控管注入实验系统,该系统包含幅频可调的微波源和移相器,由磁控管信号发生系统、注入锁定系统以及相位差检测系统3个小系统组成。利用外部注入信号,分别对磁控管输出信号的相位稳定度、频谱和相位噪声进行实验分析,实现了对实际磁控管在外部注入前后的特性分析。其中,相位差波动最小不足4°,最大17°,锁频带宽在2.9~13 MHz之间变化,在偏移频率1 MHz内对相位噪声抑制超过40 dB;并对注入锁频信号与输出信号之间的关系进行了总结,为多路大功率磁控管的功率合成提供理论依据。     

S波段15 kW连续波磁控管注入锁频实验研究

注入锁频是磁控管相干功率合成的基础,本文开展了15 kW磁控管的注入锁频实验,研究了注入微波功率与可牵引带宽之间的关系。实现了15 kW磁控管注入锁频,分析了不同注入功率下磁控管可牵引带宽。实验结果表明,磁控管注入锁频牵引带宽随注入功率增大而增加,在165 W注入功率下牵引带宽达到5 MHz。该15 kW磁控管可用于大功率微波相干功率合成,为多支大功率磁控管进行功率合成研究奠定了基础。     

C波段4路磁控管相干功率合成微波源实验研究

针对目前C波段磁控管存在的频率输出不稳定、相位输出随机移动、功率容量的物理限制等一系列问题,设计实现了基于注入锁频和反馈调相技术的C波段4路磁控管相干功率合成微波源。该微波源由三部分构成:4路独立注入锁定的磁控管单元,4路间稳频、锁频、比相的反馈控制单元,测量及显示单元。为更好的对C波段4路磁控管相干功率合成微波源进行研究,在搭建的4路磁控管微波源的平台上,对直流高压源的纹波特性、磁控管的阳极电流、功放的注入功率、4路磁控管之间的相位控制等影响微波源输出特性的相关因素进行了实验研究。最终实现微波源工作带宽:5.788GHz±2MHz;频率稳定度:0.07%;相位调节范围:0°~360°;相位调节精度:±3°;相位噪声:-40dBc/Hz@1kHz;功率合成效率:94.74%;总输出功率>2000W。     

已调信号注入磁控管的仿真研究

为克服磁控管本身固有的频谱较宽、相位噪声大等缺点,注入锁频技术被广泛地应用以获得较稳定的频率和相位差,并有效地降低相位噪声。在以往的注入锁频理论中,外部注入信号通常为一个单频信号,其频率接近磁控管自由振荡频率。而本文将一个幅度调制信号注入磁控管来取代单频信号,此时,磁控管既作为一个振荡器,又作为一个放大器。仿真结果证明,当幅度调制信号的载波频率与磁控管自由振荡频率满足Adler条件时,同样能够实现锁频。此时,磁控管输出信号可以看作为一个包络受外部注入调幅信号控制的被放大的已调信号。在此过程中,实现锁频的同时也实现了信息的传输,有望应用于携能通信中。     

大功率长寿命连续波磁控管注入锁频技术

在工业生产中加热对象往往体积庞大,微波功率不够高将直接影响加热效果,并严重制约生产规模,远不能满足大规模工业连续生产的需求。简单将多只磁控管作为独立微波源进行非相干功率合成,造成了功率合成效率低、难以消除磁控管之间相互问的干扰。严重影响微波源的工作稳定性和工作寿命,甚至直接损坏微波源。普通连续波磁控管是一种复杂幅相特性微波器件,通常其幅度易受工作条件的影响、频率和相位随机变化、幅度和相位变化相互牵连,使得进行相干功率合成具有相当大的难度。而随着注入锁频技术的引入,注入锁频连续波磁控管将能很好的解决这些问题,可实现真正意义上的相干功率合成,为微波能大规模工业应用开辟广阔的前景。     

基于注入锁频理论的扫频磁控管的理论与仿真

为了给需要大功率扫频微波源的变频微波加热、通信干扰等领域提供一种高效低成本的解决途径,在磁控管注入锁频理论的基础上,提出了一种基于磁控管的扫频大功率微波源。首先通过磁控管的等效电路模型对该设想进行了可行性分析,然后在微波仿真软件CST STUDIO SUITE中对磁控管建模并进行particle-in-cell仿真验证。分析了注入比对磁控管高频电压输出以及频谱的影响。磁控管的最高扫频带宽可达21 MHz。     

工业微波磁控管开关电源系统设计

研究了磁控管驱动电源的设计方法.主电路采用谐振拓扑结构,易于实现软开关,利用升压高频变压器的漏感作为谐振电路的一部分,简化了主电路设计.采用磁控管阳极高压和灯丝供电电压分开方案,实现灯丝电流随功率变化,来提高磁控管的使用寿命.使用PWM芯片设计了主控制电路,通过外部给定信号实现电源功率调节.设计的电源具有灯丝电流过小、高压过压、过功率、高压短路和过温等多重保护.在1500W的样机上进行了实验,对设计方法的有效性进行了验证.     

微波磁控管功率合成中基于LabWindows/CVI实现移相控制

为实现基于注入锁频磁控管的微波功率合成,提出一种使用虚拟仪器软件控制注入锁频磁控管相位的方法.基于LabWindows/CVI 软件开发的功率合成自动化操作与控制模块,实现注入锁频磁控管的微波功率合成系统的数据采集、分析处理、反馈控制等功能.系统最小移相步进为5.6°,移相范围为-180°-180°,系统处理速度达到ms 量级.实验表明,控制系统工作准确可靠,满足微波磁控管功率合成控制的需求.     

30kW连续波磁控管的研制

本文叙述了大功率连续波磁控管的研制成果,该管为2450MHz、大功率、水冷、非包装式、全金属陶瓷结构、固定频率连续波磁控管,该管最大工作效率可达72％,最大连续波输出功率可达30kW,主要用于工业加热和等离子体应用,该管的研制成功为国内微波能应用提供了高效率的微波源。     

C波段磁控管注入锁相的实验研究

为了对C波段磁控管进行大功率功率合成,须进行单管锁相研究,本文主要对单管磁控管进行注入锁相实验研究,并讨论了不同注入功率大小对磁控管输出频谱带宽的影响.实验结果表明,通过注入外部信号的方式对C波段磁控管是能够锁相成功的,锁相后输出功率稳定.在实验过程中取得了大量的试验数据,为下一步功率合成实验提供了实验基础.     

Hybrid Integrated 10-Watt CW Broad-Band Power Source at S Band

An S-band CW power source consisting of transistor-amplifier-driven varactor-doubler chains fabricated in hybrid integrated form is described. The source employs a microstrip package for high-power transistors, which has good heat sinking and low parasitic reactance and which permits direct paralleling of transistors. A breadboard model of the power source consisting of hybrid integrated components interconnected by coaxial lines produced a CW output of 9.8 watts at 3000 MHz with a 1-dB bandwidth of 6.7 percent and a dc to RF efficiency ranging from 9 to 14.5 percent over the band. The required RF input power to the module was 600 mW centered at 1500 MHz.     

5.25-W CW near-diffraction-limited tapered-stripe semiconductoroptical amplifier

A broad-area tapered-contact single-pass amplifier emitting at 860-nm wavelength is demonstrated to emit up to 5.25 W continuous wave (CW) in a near-diffraction-limited radiation pattern. The diffraction-limited component of the radiation pattern, comprising greater than 87% of the total power at 5.25-W CW output, is observed to decrease slightly with increasing drive current due to filament formation. The output beam astigmatism is found to saturate at high power output in accordance with gain saturation, which indicates that the high-quality output beam remains stable with respect to small changes in current or injected power     

A 50-GHz silicon IMPATT diode oscillator and amplifier

Recent experimental observations on a silicon impact avalanche transit-time diode oscillator and amplifier CW-operated at 50 GHz are presented. 1) CW oscillation power of 100 mW was obtained at an overall efficiency of 2 percent. The oscillation frequency was continuously tunable over a 1.3-GHz range by a sliding short. 2) Phase-locking has been achieved with a maximum normalized gain-bandwidth product of 0.1. The minimum locking signal power required for a 500-MHz locking bandwidth was 20 dB below the oscillator output. 3) Electronic tuning of the oscillator frequency was demonstrated by placing a millimeter-wave varactor diode in the tuning circuit. The output frequency versus the bias voltage on the varactor diode was linear with maximum frequency deviation of 300 MHz. Frequency modulation of the oscillator by driving the varactor with a sinusoidal source was obtained at a modulation frequency of 50 MHz. 4) Stable amplification with 13-dB gain was obtained, centered at 52.885 GHz with a 3-dB bandwidth of 1 GHz. The maximum output power obtained was 16 mW. Higher gain of about 17 dB was obtained at a reduced bandwidth. The noise figure of the amplifier was 36 dB. Equivalent circuits for the oscillator and the amplifier are derived. The calculated results agree reasonably well with the experimental observations.     

Light-emitting diode emitting at 650 nm with 200-MHz small-signalmodulation bandwidth

State-of-the-art modulation bandwidths are presented for multiquantum well resonant cavity light emitting diodes (RCLED's) emitting at 650 nm. 84-μm size epoxy coated RCLED's have a 1.4-mW (CW) output power and a small signal modulation bandwidth of 200 MHz at 40 mA bias. 150-μm diameter devices yield 3.25-mW and 150-MHz bandwidth at 70-mA bias. An open eye-diagram at 622 Mb/s achieved for the 84-μm device makes it very attractive for SONET OC-12 data communication links     

一种新颖的毫米波集成功率合成器

本文介绍一种结构新颖的毫米波Ｅ面混合集成功率合成器及其设计方法。功率合成器电路由鳍线和Ｅ面线构成,输出端口为标准矩形波导。具有结构紧凑、调试简便的优点。采用两耿氏管,在Ｋａ波段,６３０ＭＨｚ的机械调谐带宽内连续波输出功率大于２００ｍＷ,最大输出功率为２９３ｍＷ。     

High-performance experimental power triodes

The plate current, transconductance, gain-bandwidth product, and power output capabilities of small planar triodes have been increased nearly tenfold over that obtained from present day commercial tubes of comparable size and weight. In the new experimental triodes, the cathode can supply a CW current density of 1.6 A/cm². A closely spaced, rigidly supported grid structure can provide a transconductance of 0.7 mho. The output capacitance is low enough to render a gain-bandwidth product of 22 Gc/s at 1.3 Gc/s. In this frequency range, the CW power output capability is 1 kW, and the pulsed power output capability in a 10-percent bandwidth circuit is 5 kW with 500 μs pulses at a duty factor of 0.07.     

X频段10 kW速调管功放在深空地面站的应用

速调管因具有输出功率大、效率高、成本低、工作稳定可靠的优点,在微波发射系统中占据着重要的地位。近年来,国内速调管功放取得了较大的进展,连续波输出功率从几百瓦提升到十千瓦。采用固态+速调管放大方案,设计一套X频段10 kW连续波速调管功率放大器,工作带宽为95 MHz。该功放应用于深空地面站,是深空探测发射分系统的重要组成部分。文中主要描述了速调管功放的组成、主要技术性能和测试结果。测试数据表明,X频段10 kW速调管功放工作稳定、可靠,且完全符合设计要求     

530～650MHz 20W CW Si-VDMOS场效应晶体管

报道了530~650MHz 20W连续波Si-VDMOS场效应晶体管的研制结果。该器件采用polySi/WN/Au的多层复合栅技术降低栅串联电阻,采用栅下场氧化垫高技术降低反馈电容,采用穿通型硅外延材料优化导通电阻提高器件工作效率,全离子注入自对准工艺等技术,在上述频带内,连续波,28V工作电压下,静态电流50mA,该器件输出功率达20W,效率达49%,增益大于7.5dB。     

A Two-Point Modulation Technique for CMOS Power Amplifier in Polar Transmitter Architecture

A two-point modulation technique is presented that improves the performance of nonlinear power amplifiers (PAs) in polar transmitters. In this scheme, the output amplitude modulation is performed by controlling the current of the PA. The current control technique enables the PA to provide wideband amplitude modulation, as well as high power control dynamic range. In addition, the supply voltage of the PA is adjusted based on the output power level. The voltage supply adjustment substantially improves the effective power efficiency of the PA. The voltage supply control is performed using a second-order sigma-delta dc-dc converter, which presents an efficiency of over 95% in its operational range. The PA operates at 900 MHz with maximum output power of 27.8 dBm and power efficiency of 34% at maximum output power. The proposed PA achieves 62-dB power control dynamic range with amplitude modulation bandwidth of over 17.1 MHz. The circuits are fabricated in a CMOS 0.18 mum process with a 3.3-V power supply.