130MW大功率线型脉冲调制器的设计与研究

为解决国家同步辐射实验室直线微波源末级放大器速调管来源及满足后期升能的需要．研制了6台大功率线型脉冲调制器,作为E3730A速调管的阴极脉冲调制器,该调制器采用恒流充电高压逆变电源为调制器人工线（PFN）充电,输出130MW脉冲功率。对该调制器的设计原理进行了介绍,对其放电电路、放电开关、充电电路的工程实现进行了分析,详细讨论了旁路电路的作用及工程设计,指出采用同轴电缆传输高压充电能量必须采用旁路电路的必要性,最终给出了调制器的研制结果及应用情况。     

400MHz PSK卫星通信调制器的设计

卫星数据通信往往采用PSK调制方式传输数据信号,本文介绍采用DDS芯片AD7008组成的400MHz卫星通信PSK调制器的电路设计方法,利用集成DDS调制芯片AD7008方便地实现PSK调制,再采用锁相环路把调制信号搬到400MHz载频上,最后给出了该PSK调制器的性能指标。     

基于DDS的π/4-DQPSK调制器设计

π/4-DQPSK调制方式广泛应用于无线通信领域,而全数字合成技术应用于卫星通信和移动通信领域。简要介绍了DDS原理和π/4-DQPSK调制原理。提出了一种新颖的全数字中频π4-DQPSK调制器,该调制器采用DDS技术和先进的FPGA技术。给出了该调制器的硬件实现,并从原理上进行了必要的分析。实验结果表明:提出的设计方案能很好地实现π/4-DQPSK调制,与一般的调制器相比,具有可重新配置、灵活性好、工作更加稳定等优点。     

小型化高压固态脉冲调制器

针对高峰值功率发射机调制器的技术要求,介绍了常用的线型调制器和固态刚管调制器电路拓扑,讨论了不同调制器的特点和适用场合。介绍了小型化高压固态脉冲调制器的电路拓扑,分析了影响调制器性能的主要因素。该调制器基于单个大功率绝缘栅双极型晶体管模块和初级采用多组导线并联绕制的脉冲变压器,并采用能量回馈电路来箝位脉冲变压器的反峰电压。文中给出了调制器的输出脉冲波形,并指出了该调制器的适用场合。     

一种宽适应高电位脉冲调制器的实现方法

介绍了一种宽适应高电位脉冲调制器的实现方法。调制器由初级脉冲形成电路、隔离变压器、次级脉冲恢复电路组成。采用CPLD将初级脉冲分离形成开启、关断和截尾脉冲,通过变压器隔离传输,并利用MOSFET极间分布电容的充电延时特性,最终输出调制脉冲。还介绍了该调制器的设计实例,给出了性能测试结果。     

10.6μm碲化镉电光调制器的实验研究

介绍了一个采用国产材料自行研制的碲化镉电光调制器的特性，给出了对该调制器的调制特性及频率响应实验曲线，对各实验结果及调制器性能改善进行了分析。     

结构简单的双信道偏振位移键控光通信系统

提出采用两个光相位调制器组成一个电-光偏振调制器实现双信道偏振位移键控(PolSK)光通信系统方案,并进行了仿真验证.分析了系统的工作原理,给出了关键点的信号的琼斯矢量和星座图,并通过系统仿真计算出了偏振接收、解复用后的双信道数据信号的时间波形.该系统在发射机端,采用平行相位调制方式实现了双信道数据的复用,在接收机端,...     

宽带数字调制器设计实现

针对现代数字通信系统中广泛使用的宽带数字调制,分析了其矢量合成原理,并采用统一的FPGA硬件平台、算法软件实现、IF/RF矢量调制器来实现。文中给出了实现电路原理,对实际的幅度与相位不平衡给出补偿解决办法。最后给出了多进制相移键控(MPSK)调制器测试数据,其性能优良,可以满足多频段扩跳频数据传输要求。     

300 kW线型调制器的设计

介绍了一个300 kW线型调制器的设计原理。阐述了采用电流互感器作为触发方式的优点,给出了调制器的均压、反峰、阻尼和保护电路的设计方法,最后简要介绍了串联可控硅的散热方法和调制器工作时的测试波形。实际应用结果表明该调制器性能稳定可靠。     

几种全固态刚管调制器的对比

随着固态开关器件串并联技术的发展,采用多个全固态开关管串并联实现大功率全固态刚管调制器的技术越来越成熟.文中介绍了近年来大功率全固态刚管脉冲调制器的发展情况,分析了各种类型的刚管调制器特点和关键技术,给出了几种调制器的典型波形,分析了各自的应用场合,同时对各种调制器的优势进行了总结,对应用前景进行了展望.     

脊波导结构LiNbO3调制器的分析与设计

本文利用保角变换法对脊波导结构调制器进行了分析,特别针对在制做脊波导时的非理想矩形的情况,对它造成的偏差进行了计算,在此基础上得出了脊型共面波导结构调制器的等效折射率,特性阻抗,调制带宽和驱动电压等特性。在速度匹配,阻抗匹配,半波电压以及制做的困难程度等折中考虑下对调制器的各项参数进行了优化。结果表明了这新型结构在保持较大特性阻抗的同时,有效的降低等效折射率,大大地提高了调制带宽,迎合了更高速光纤通信的要求。     

High-speed and low-driving-voltage X-cut LiNbO3 opticalmodulator with two step backside slot

A newly designed low-driving-voltage X-cut lithium niobate optical modulator with a two step backside slot is proposed. This modulator was fabricated with micro-machining technology utilising excimer laser ablation. The modulation bandwidth of this modulator achieves 25 GHz and the driving voltage is 2.8 V at 1 kHz     

Micro Fabry Perot light modulator for flat panel display

A new type of Fabry Perot light modulator for displays based on micro-electro-mechanical system technology is proposed. Multiple beam interference theory is used to design the modulator and analyze its characteristics. If Fabry Perot cavity length is one-quarter of the incident wavelength, the transmitted light is blocked by the modulator, and the modulator, which is illuminated from its backside, appears black. If the Fabry Perot cavity length is 0 or one-half of the incident wavelength, light may transmit the Fabry Perot modulator from its backside, and the modulator appears bright. Hence, the modulator may be used for flat panel displays. In this paper one Fabry Perot light modulator based on surface microma-chining technology is introduced. The designed modulator has a contrast ratio of 150 and can theoretically be driven by a voltage of 2.4 V.     

一种低电压的Sigma-Delta ADC新结构

介绍了一种低电压Sigma-Delta ADC新结构,该结构采用了二阶单位增益ΣΔ调制器和一阶传统ΣΔ调制器相结合的方式,既可以从系统级降低对运放直流增益等非理想因素的要求,又可以减少加法器的个数、降低电路的复杂度。在此基础上,采用HJTC0.18μm1.8V/3.3V1P6M混合信号工艺,实现了一种1V工作电压的ΣΔ调制器,经测试动态范围可以达到69.5dB。     

Very low-voltage digital-audio ΔΣ modulator with 88-dBdynamic range using local switch bootstrapping

A 1-V 1-mW 14-bit ΔΣ modulator in a standard CMOS 0.35-μm technology is presented. Special attention has been given to device reliability and power consumption in a switched-capacitor implementation. A locally bootstrapped symmetrical switch that avoids gate dielectric overstress is used in order to allow rail-to-rail signal switching. The switch constant overdrive also enhances considerably circuit linearity. Modulator coefficients of a single-loop third-order topology have been optimized for low power. Further reduction in the power consumption is obtained through a modified two-stage opamp. Measurement results show that for an oversampling ratio of 100, the modulator achieves a dynamic range of 88 dB, a peak signal-to-noise ratio of 87 dB and a peak signal-to-noise-plus-distortion ratio of 85 dB in a signal bandwidth of 25 kHz     

Direct quadrature phase shift keying modulator using six-port technology

A direct quadrature phase shift keying modulator based on six-port technology is presented. The modulator comprises a six-port circuit, a switch matrix and open and short terminations. Using this modulator, direct phase shift keying modulation was achieved. Six-port technology has the advantage of signal integrity, low power consumption and physical scalability to attain different frequencies of operation and extendibility to M-ary phase shift keying. Experiment results demonstrate performance with an output phase difference from 0.8 to 4.5/spl deg/ and an amplitude difference from 0.5 to 2.7 dB. A data throughput of 200 Mbits was attained.     

Single-loop delta-sigma modulator with swing suppression

A single-loop higher-order delta-sigma modulator with a new loop topology is presented. The loop-filter is composed of both feedback and feedforward paths. No active summing element is required in the modulator implementation. The modulator has low integrator output swings and a high input dynamic range, resulting in relaxed op-amp requirements even for low-voltage operation. Simulation results of a fourth-order modulator having the proposed loop filter are also given     

一种12位开关电流型Σ-△调制器

开关电流电路（ＳＩ）是近年兴起的一种模拟电路。文中引用了新型的两步采样开关电流技术（Ｓ＾２Ｉ）,对该电路中减小时钟馈漏效应的几种方法进行了分析。利用差分平衡结构的Ｓ＾２Ｉ存储单元设计了平衡Ｓ＾２Ｉ积分器,并在此基础上设计出一种平衡差分结构的二阶∑－△调制器。该调制器能够完全与标准ＣＭＯＳ数字工艺兼容。利用标准１．２μｍ数字ＣＯＭＳ工艺的ＨＳＰＩＣＥ模型参数进行了分析,该电路信噪比达到７３．３ｄＢ,     

Impedance Transformations For The Generalized Reflection Modulator

A procedure is given for obtaining the impedance transformer which will produce a prescribed pair of phasor reflection coefficients by transformation from a given pair of impedance states terminating the transformer. The transformer may be used in a general two-state reflection modulator: as a phase shifter with phase change at constant amplitude or as an amplitude modulator with level shift at constant or variable phase. The condition governing the reflection coefficients available from a given pair of impedance states is given. Examples and limitations are discussed.