A W-band high-power predistorted direct-conversion digital modulator for transmitter applications

This letter presents a W-band high-power direct-conversion transmitter using digital predistortion techniques for digital modulation applications. The transmitter is a direct-conversion configuration that employs a reflection-type IQ modulator module and a power amplifier module. With the predistortion function in digital signal processing (DSP), this transmitter demonstrated an output channel power of greater than 19 dBm, and the adjacent channel power ratio (ACPR) was improved by 10 and 18 dB for QPSK and /spl pi//4-DQPSK modulation, respectively. To the best of our knowledge, this is the first demonstration of linearization techniques for W-band high-power digital modulation transmitters.     

A new three-terminal thyristor-based high-power switchingconfiguration with high-voltage current saturation

A new high-voltage power switch configuration having thyristor based on-state current conduction together with high-voltage current saturation characteristics is described. Current saturation is obtained in the new thyristor structure by diverting part of the base current at a predesigned current level to bring the NPN and PNP transistors comprising the thyristor out of their regeneratively-coupled conduction mode. The concept has been experimentally verified by fabricating 1200 V, 175 A devices     

射频宽带大功率放大器模块

利用推挽MOSFET晶体管,通过采用传输线变压器宽带匹配技术,研制出一种宽频带高功率放大器模块。文中给出了测试结果,模块的性能指标良好。     

Photo-injection p-i-n diode switch for high-power RF switching

The high RF power-switching properties of the photo-injection p-i-n switch (PIPINS), an optically controlled RF switch, are investigated. Proper functioning of a PIPINS as a low insertion-loss RF switch requires that it operates as a photoconductor, where the photo-injected charge is much greater than the RF sweep out charge. Insertion loss using 650-mW optical power was <0.4 dB at RF (VHF-UHF) power in excess of 200 W, and devices successfully standoff 200-W incident RF power with the series isolation being determined by the device capacitance (e.g., 225 fF). PIPINS hot-switching measurements are reported for the first time, with output RF power up to 180 W at low duty cycle, rise times of 1 ps, and fall times for a series shunt switch of ≈2.5 μs. The RF power for hot switching a PIPINS is limited by a latch-on effect, which is dependent on a variety of parameters, including duty cycle and repetition period, consistent with thermally generated carriers contributing to the latch-on effect. The switching properties of PIPINS make them a candidate for high RF power applications such as reconfigurable antennas, where electromagnetic isolation of the switch and control lines are critical     

铜蒸气激光器中高压大功率脉冲变压器的研制

为了实现铜蒸气激光器电源的小型化,采用高压大功率脉冲变压器对储能电容进行开关脉冲充电的电路拓扑,通过建立设计和输出模型,采用铁基超微晶材料,研制了高压大功率脉冲变压器,在14kHz下实现了13kV的充电电压,传输功率超过2．3kW。通过控制IGBT的触发脉宽,可实现输出电压和功率的调节。     

级联型变频器在高压大功率电机软启动中的应用

为了解决高压大功率电机软启动技术实现难的问题,文中介绍一种基于单元级联型高压变频器的电机软起动应用方法,利用高压大功率变频器的特点,用其作为高压大功率电机的软启动器,使得高压大功率电机能够平稳、无冲击、大转矩启动。     

The design of high-voltage high-power silicon junction rectifiers

A set of curves is presented. These curves can be easily used to obtain the tradeoff relations between the reverse and the forward voltages of high-voltage p-i-n rectifiers. By using the lifetime as a parameter, those curves can also be used to achieve compromises between the forward voltage and the recovery time.     

大功率半导体激光器恒流源设计

介绍了一种单片机控制的大功率半导体激光器的恒流源电路设计,其输出电流在0-65A连续可调,电流控制精度可达3‰以上.同时,该电路还可以控制半导体激光器的工作温度,并可通过电脑方便地对温度进行设置.     

Susceptibility of lithium-niobate modulator to high-power microwave pulses

The first measurement of the susceptibility of an off-the-shelf lithiumniobate intensity modulator to damage and disruption from high-power microwave pulses is reported. The device tested survived 1 kHz repetition rate pulses at 2.5 GHz centre frequency and 40 μs width up to 200 W peak power. The results are discussed in terms of material parameters and device characteristics.     

A 10-bit wide-band CMOS direct digital RF amplitude modulator

This paper describes a low-distortion wide-band CMOS direct digital RF amplitude modulator, which uses a 10-bit linear interpolation current-steering digital-to-analog converter (DAC) and a Gilbert-cell-based mixer to generate an amplitude modulated RF signal directly. The linear interpolation increases the attenuation of the DAC's image components. The reconstruction filter is, therefore, eliminated. The DAC's differential current signals are directly sent to the mixer, which improves the linearity of the modulated RF signal. Thus, the RF transmitter structure is simplified, and the low distortion is achieved. This modulator is suitable for system-on-chip (SOC) design and is easily scalable. The chip was fabricated in a 0.35-/spl mu/m 3.3-V double-poly triple-metal CMOS process. The core size of the chip is 0.52 mm/spl times/0.68 mm. With a 3.3-MHz modulation signal, a 50-MHz clock, and a 1-GHz carrier, the distortion components are below -53.81 dBc, and the attenuation of the image signal is 47.45 dB. The output power is -6.5 dBm, and the total power consumption is 159.8 mW.     

高功率DPL用声光Q开关组件

文中介绍了应用于高功率DPL调Q的声光Q开关组件,描述了声光Q开关的工作原理,着重介绍了声光Q开关关键指标衍射效率、插入损耗的设计方法,给出了驱动电源的设计框图、调Q同步电路的设计考虑,降低电脉冲下降时间的思路,得到了工作波长1.064μm,通光长度44 mm,光束直径3.5 mm,衍射效率85%,关断DPL连续功率331 W,腔内插入损耗8%,内调制频率500 Hz～10 kHz连续可调,电脉冲下降时间100 ns,电路延时时间50 ns～1μs可调的实验结果.该组件衍射效率高、插入损耗低.已小批量用于激光表演机、大功率激光打标机,激光毛化机等系统中,也可用于激光测距机、激光雷达、激光卫星间通信等方面,具有广阔的应用前景.     

40-Gb/s high-power modulator driver IC for lightwave communicationsystems

A monolithic integrated modulator driver with a data decision function for high-speed optical fiber links is presented. The integrated circuit (IC) was manufactured in a 0.2-μm gate length AlGaAs/InGaAs high electron mobility transistor technology with an f_T of 68 GHz. The modulator driver IC features differential configuration and operates up to 40 Gb/s with a clock phase margin of 210° and an output voltage swing of 2.9 V_p-p at each output. The maximum slew rate of the output signal is 200 mV/ps. The power dissipation of the circuit is 1.6 W using a single supply voltage of -5 V     

A multidimensional variable band flux modulator for four-phase-leg voltage source inverters

This paper presents a multidimensional flux modulator for closed-loop control of the output voltage of a four-phase-leg inverter. The proposed strategy uses flux regulated hysteresis with a rectangular bounding cube in the synchronous d-q-o reference frame, and a simple set of switching rules to ensure the selection of only the nearest active space vectors to the target reference phasor. In addition, the inherent optimal sequencing and central placement of active vectors between successive s result in the modulator having an improved performance as compared to other reported hysteresis schemes. A further enhancement is achieved by adjusting the dimensions of the bounding cube to restrict the switching process to the nearest three active vectors (and vectors) within a constant switching period. Under this constraint, the modulator achieves a harmonic performance virtually identical to the well-known open-loop space vector modulation. But since the modulator is a closed-loop system, it also exhibits excellent robustness to system parameter variations. The performance and practicability of the modulator have been verified both in simulation and experimentally.     

Linearized microring-loaded Mach-Zehnder modulator with RF gain

A linearized modulator based on the Mach-Zehnder interferometer (MZI) loaded with a second-order allpass microring resonator is proposed and analyzed. The device is shown to exhibit much smaller intermodulation distortion than standard Mach-Zehnder modulators, thus greatly enhancing the device dynamic range. Gain effect associated with the microring resonance results in a modulator transfer function with high slope efficiency and large RF gain. Moreover, combined with the use of a highly electrooptic polymer, the high slope efficiency allows for the possibility of realizing modulators with subvolt drive voltage. The detrimental effect of loss in the microring resonators on device performance is also investigated and a design approach to mitigate its effect is presented. The proposed modulator can be linearized to any arbitrary nth order by loading the MZI with a higher order allpass microring resonator.     

A 13-bit, 1.4-MS/s sigma-delta modulator for RF baseband channelapplications

A 13-bit, 1.4-MS/s, sixth-order cascaded sigma-delta modulator oversampling at 16 X is implemented in a 0.72 μm complementary metal-oxide-semiconductor process for use in the baseband path of a radio-frequency receiver. The modulator achieves 77 dB of dynamic range and dissipates 81 mW from a 3.3 V supply. It is characterized for the blocking and intermodulation requirements of a cordless telephone application     

Double-ended thyratrons in high-power burst mode pulse modulator applications

The use of four-gap double-ended thyratrons in a 30- to 100-µs pulse modulator is described. The PFN-type modulator operates at 105-kV peak, charged from the 11-kV public supply, and powers an ill-matched and potentially unreliable load directly at 30 to 70 kV without a pulse transformer. The maximum repetition rate is 200 pps. The completed modulator has been delivered to the customer and successfully recommissioned. Satisfactory operation is reported with 200-MW 6-kJ pulses in bursts of average power up to 400 kW; this is well in excess of the published ratings of the tubes employed. The methods used to obtain this performance are discussed and the main details are given of pulse discharge, energy dump, and switched charge circuits appropriate to the thyratrons used. The possibility of uprating the modulator is mentioned, and certain recent developments in large thyratrons are discussed. These include a new pentode-type electrode system which should give improved performance with simpler deck circuitry. For extended bursts at long pulse lengths the realistic maximum capability of single tubes in current production seems to be about 1-GW peak at 2-MW average power.     

高功率馈源设计研究

在分析高斯场与规则波导模式关系的基础上,分别运用数值求解耦合波方程和级连模匹配技术计算了圆波导H11模在不同形状渐变张角喇叭传输过程中与高次模式的耦合过程。在大量计算分析的基础上选择了其中一条曲线加工了实验馈源,利用实验和仿真的结果验证了数值模拟程序的正确性,从实践上确认了利用耦合波理论和模匹配技术设计高功率光滑变张角圆锥高斯馈源的可行性,为进一步分析设计实用型高功率高效率馈源打下了基础。     

应用数字PWM器件SA4828的大功率直流电源

本文介绍一种智能型、高精度PWR控制器SA4828，其控制实行全数字化产生三相脉宽调制波形．本文采用此器件设计大功率直流电源应用于22KW直流电机测试，对感性负载表现出具有纹波小，响应迅速、硬件电路简洁、控制简单易于编写的优点。     

Effect of high-power RF impulses on the mixer operation

The results of the experimental investigation of mixers operating under the action of high-power interference impulses are presented. The changes in the IF-signal shape occurring as the interference power changes are analyzed.     

A high-power pulsed xenon ion laser as a pump source for a tunable dye laser

An inexpensive pulsed xenon ion laser with peak power outputs up to 4 kW has been constructed and used as a pump source for a tunable rhodamine 6G dye laser with a 0.25-Å bandpass in the yellow-red range of the spectrum. The dye laser is tunable from 5465 to 6300 Å. Over 50 W are obtained at the peak of the tuning range.