一种S波段固态发射机的设计

介绍一种S波段固态发射机的设计,本发射机是脉冲工作,空间合成式,输出脉冲功率8Kw,工作比为10%.     

高稳定激光二极管抽运Nd:YLF再生放大器

设计并实现了一种放大纳秒激光脉冲的高稳定的激光二极管(LD)抽运Nd:YLF再生放大器.为了获得高稳定的输出,再生放大器工作在饱和状态.此时,再生放大器输出稳定性最好,而且注入激光脉冲能量波动引起的输出激光脉冲波动被抑制.由于增益饱和效应,再生放大器输出脉冲出现时域波形失真,附加后缀脉冲能够减弱时域波形失真.放大器工作波长1053 nm,工作频率1 Hz.输入240 pJ的3 ns方波激光脉冲,输出激光脉冲能量4.2 mJ,总增益大于107,不稳定度小于1%(均方根),方波扭曲1.33.为3 ns方波激光脉冲引入其本身幅度0.75倍的后缀脉冲,输出激光脉冲方波扭曲由1.33降至1.17.     

CMOS wireless phase-shifted transmitter

A fully integrated phase-shifted (PS) transmitter is presented in this paper. The PS transmitter employs switching power amplifiers, operates without mixers, and provides an intermodulation distortion-free output spectrum, making it a suitable choice for mobile communication systems. The RF blocks of the PS transmitter include a local oscillator, phase shifters, and switching class-F power amplifiers with wide-band matching networks. The PS transmitter is implemented in a standard single-polysilicon, six-metal 0.18-/spl mu/m CMOS technology and occupies an area of 3 mm/sup 2/. It operates from a 1-V supply and provides better than 42 dBc adjacent channel power ratio with an output bandwidth of 50 MHz at 8 GHz. The PS transmitter RF front-end provides 22 dBm of average output power with a 38% average power added efficiency.     

A 3-5 GHz BPSK transmitter for IR-UWB in 0.18μm CMOS

This paper presents a transmitter IC with BPSK modulation for an ultra-wide band system.It is based on up-conversion with a high linearity passive mixer.Unlike the traditional BPSK modulation scheme,the local oscillator (LO) is modulated by the baseband data instead of the pulse.The chip is designed and fabricated by standard 0.18μm CMOS technology.The transmitter achieves a high data rate up to 400 Mbps.The amplitude of the pulse can be adjusted by the amplitude of the LO and the bias current of the dri...     

3–5 GHz FSK-OOK ultra wideband transmitter based on memristive ring oscillator

The compatibility of a memristor with CMOS technology has attracted the attention of many researchers to explore its application further. In this work, an ultra low-power and low-complexity ultra wideband (UWB) chirp transmitter based on memristive ring oscillator (RO) is designed in 0.18 µm TSMC CMOS technology. The Chirp waveform was chosen because of its low side-lobes and large time-bandwidth product, which allows for more spectrum use. OOK and FSK modulation are supported by the proposed UWB chirp transmitter. The chirp frequency is controlled linearly with time across the pulse duration using memristors. The binary data "1" and "0" are encoded using distinct chirp frequencies in FSK TX. The simulation results show a maximum TX output pulse of 457 mV _Vpp with a pulse width of 21 ns. The overall DC power consumption for a pulse repetition frequency (PRF) of 20 MHz is 0.328 mW, equivalent to an energy consumption of 16.4 pJ/pulse. The simulated output amplitude for OOK TX is 453 mV Vpp with a pulse width of 48 ns and a PSD of ? 10 dB over a frequency range of 3.2 to 4.8 GHz. The overall power consumption at 10 MHz PRF is 0.136 mW, which corresponds to an energy consumption of 13.6 pJ/pulse.

     

Analysis and Design of a W-band Coherent Pulsed Transmitter Using a New Timing Scheme

This paper presents the analysis and design of a new W-band pulsed transmitter using injection-locking to achieve pulse-to-pulse coherence and power amplification. First, a new timing scheme is introduced to solve the asynchronous problem that commonly exists in multistage injection-locked transmitters. Then the pulsewidth of one stage in the transmitter is intentionally made somewhat longer than that of the next stage, and thus, the rising edge noise of the output pulse is minimized. Finally, a high coherent peak power can be achieved without using complex power combing techniques. To verify our analysis, a W-band pulse transmitter is designed and fabricated that operates at a 78 ns pulsewidth, 50 μs pulse period, and 600 MHz locking bandwidth. The experiment shows that a coherent peak power of 22.3 ± 0.9 W was achieved at 94.2 GHz.     

Line strip spot-diffusing transmitter configuration for optical wireless systems influenced by background noise and multipath dispersion

In this letter, we propose and evaluate a novel optical wireless configuration that employs a multibeam transmitter in conjunction with a narrow field-of-view direction diversity receiver. Such a configuration overcomes the drawbacks and combines the advantages of both types of optical wireless links, including line-of-sight and diffuse transmission. A multibeam transmitter placed on the communication floor was adopted to produce multiple diffusing spots on the middle of the ceiling in the form of a line strip. The design goal is to reduce the effect of intersymbol interference and to improve the signal-to-noise ratio (SNR) when the system operates under the constraints of background noise and multipath dispersion. Simulation results show that our line strip multibeam transmitter (LSMT) with only three branches diversity gives about 23 dB SNR improvement over the conventional system. The results also show that the multipath dispersion, which induces pulse spread, is significantly reduced when the LSMT with diversity detection is used.     

A 132 Mb/s, 1bit 4224 M samples/s sub-sampling, low-complexity and energy-efficient BPSK transceiver for all-digital 3–5 GHz IR-UWB

In this paper, a 3–5 GHz impulse radio ultra wideband BPSK transceiver is presented. A new all-digital architecture is applied in the proposed transceiver. The transceiver has no mixer and low complexity. The transmitter employs a RLC network response filter to achieve the adjustable pulse parameters, which includes pulse width, pulse bandwidth and pulse amplitude. Considering the low duty ratio, a proposed on/off output buffer in the transmitter is applied to save the power consumption. To simplify the receiver, the radio frequency input signal is amplified and sampled directly by a 1bit 4224 MHz sub-sampling ADC. The ADC comprises by 16 paralleled comparators for low power. Each comparator operates at 264 MHz and can be self-calibrated. The transceiver is implemented in SMIC 0.13 μm CMOS process at the supply of 1.2 V. The measured results show the adjustable parameters: the pulse amplitude is from 110 to 370 mV, the pulse width is from 900 to 1,600 ns and the pulse bandwidth is from 2.0 to 2.78 GHz. The data rate is 132 Mb/s between the transceiver. The transmitter and the receiver only consume 18.2 and 330 pJ/pulse, respectively. The receiver sensitivity is ?75 dBm at the bit error rate of 10^?3.     

A fully integrated differential impulse radio transmitter

This paper presents a fully integrated differential impulse radio transmitter for ultra-wideband (UWB) applications. The design features low power dissipation, simple hardware, and a precise differential pulse shape. The transmitter employing the time hopping pulse position modulation (TH-PPM) scheme supports eight simultaneous users’ access with 2.5-ns hopping time allocated in a frame time of 20 ns. A differential 5th-derivative Gaussian pulse generator (PG) is designed for the first time to regulate the pulse shape so as to automatically satisfy the Federal Communications Commission (FCC) spectrum mask. The transmitter in a 1.8-V 0.18-μm CMOS process is realized in an IC area of 629 μm × 797 μm for its all digital circuit design. The measured digital pulse width of the TH-PPM pulse train is 2.5 ns and the measured 5th-derivative Gaussian pulse has a peak-to-peak amplitude of 154 mV and a pulse width of 820 ps. The power dissipation of the transmitter is 23 mW.     

Ultra-wide-band transmitter for low-power wireless body area networks: design and evaluation

The successful realization of a wireless body area network (WBAN) requires innovative solutions to meet the energy consumption budget of the autonomous sensor nodes. The radio interface is a major challenge, since its power consumption must be reduced below 100 /spl mu/W (energy scavenging limit). The emerging ultra-wide-band (UWB) technology shows strong advantages in reaching this target. First, most of the complexity of an UWB system is in the receiver, which is a perfect scenario in the WBAN context. Second, the very little hardware complexity of a UWB transmitter offers the potential for low-cost and highly integrated solutions. Finally, in a pulse-based UWB scheme, the transmitter can be duty-cycled at the pulse rate, thereby reducing the baseline power consumption. We present a low-power UWB transmitter that can be fully integrated in standard CMOS technology. Measured performances of a fully integrated pulse generator are provided, showing the potential of UWB for low power and low cost implementations. Finally, using a WBAN channel model, we present a comparison between our UWB solution and state-of-the-art low-power narrow-band implementations. This paper shows that UWB performs better in the short range due to a reduced baseline power consumption.     

An Energy-Efficient All-Digital UWB Transmitter Employing Dual Capacitively-Coupled Pulse-Shaping Drivers

This paper presents an all-digital, non-coherent, pulsed-UWB transmitter. By exploiting relaxed center frequency tolerances in non-coherent wideband communication, the transmitter synthesizes UWB pulses from an energy-efficient, single-ended digital ring oscillator. Dual capacitively coupled digital power amplifiers (PAs) are used in tandem to attenuate low frequency content typically associated with single-ended digital circuits driving single-ended antennas. Furthermore, four level digital pulse shaping is employed to attenuate RF sidelobes, resulting in FCC compliant operation in the 3.5, 4.0, and 4.5 GHz IEEE 802.15.4a bands without the use of any off-chip filters or large passive components. The transmitter is fabricated in a 90 nm CMOS process and occupies a core area of 0.07 mm$^2$ . The entirely digital architecture consumes zero static bias current, resulting in an energy efficiency of 17.5 pJ/pulse at data rates up to 15.6 Mb/s.      

输出大啁啾脉冲的展宽脉冲锁模光纤激光器

报道了一种大啁啾脉冲输出的全光纤展宽脉冲锁模激光器,以非线性偏振旋转(NPR)实现自启动锁模。激光器其余部分为全单模光纤(SMF)结构,提供很大的正色散,光栅对提供色散补偿,输出展宽脉冲。实验中得到了重复频率36.96MHz,单脉冲能量1.81nJ的稳定锁模脉冲序列,使用频谱分析仪观测得到脉冲序列一次谐波信噪比(SNR)达到80dB。直接输出脉冲有很大的正啁啾,脉宽为2.17ps,经过腔外压缩可获得70fs的脉冲。这种能压缩到百飞秒量级的大啁啾脉冲非常适用于光纤啁啾脉冲放大(CPA)系统。     

The future of terrestrial broadcasting-the short-wave supertransmitter

The author discusses the development of single-sideband broadcasting and the short-wave super transmitter. The use of pulse duration modulation to reduce energy costs is discussed. Other energy saving methods such as dynamic amplitude modulation are also discussed. The author describes single-tube-equipped 500 kW transmitter technology     

Distributed Waveform Generator: A New Circuit Technique for Ultra-Wideband Pulse Generation, Shaping and Modulation

A new circuit technique, the distributed waveform generator (DWG), is proposed for low-power ultra-wideband pulse generation, shaping and modulation. It time-interleaves multiple impulse generators, and uses distributed circuit techniques to combine generated wideband impulses. Built-in pulse shaping can be realized by programming the delay and amplitude of each impulse similar to an FIR filter. Pulse modulation schemes such as on-off keying (OOK) and pulse position modulation (PPM) can be easily applied in this architecture. Two DWG circuit prototypes were implemented in a standard 0.18 $muhbox{m}$ digital CMOS technology to demonstrate its advantages. A 10-tap, 10 GSample/s, single-polarity DWG prototype achieves a pulse rate of 1 GHz while consuming 50 mW, and demonstrates OOK modulation using 16 Mb/s PRBS data. A 10-tap, 10 GSample/s, dual-polarity DWG prototype was developed to generate UWB pulses compliant with the transmit power emission mask. Based on the latter DWG design, a reconfigurable impulse radio UWB (IR-UWB) transmitter prototype was implemented. The transmitter's pulse rate can be varied from 16 MHz range up to 2.5 GHz. The bandwidth of generated UWB pulses is also variable, and was measured up to 6 GHz (${- 10} {rm dB}$ bandwidth). Both OOK and PPM modulation schemes are successfully demonstrated using 32 Mb/s PRBS data. The IR-UWB transmitter achieves a measured energy efficiency of 45 pJ/pulse, independent of pulse rate.      

用1553nm激光脉冲触发GaAs光电导开关的研究

用1553nm飞秒光纤激光器触发半绝缘GaAs光电导开关的实验表明,当光电导开关处于3.33～10.3kV/cm的直流偏置电场并被脉冲宽度200fs且单脉冲能量0.2nJ的激光脉冲照射时,开关表现为线性工作模式,开关输出峰值电压为0.8mV.分析表明,开关对波长为1553nm触发激光脉冲表现出的弱光电导现象起因于半绝缘GaAs材料EL2深能级的作用.     

Influence of a step-tapered undulator field on the optical pulseshape of a far-infrared free-electron laser

The optical output of the free-electron laser for infrared experiments (FELIX), which operates in the regime of strong slippage, consists of picosecond pulses. Depending on the amount of cavity desynchronization, the optical pulse can develop substantial structure in the form of multiple subpulses. We present second-order autocorrelation measurements of the subpulses at several far-infrared wavelengths while applying a step-taper in the undulator field. The operation with a step-tapered undulator prevents the electrons from reabsorbing the optical field energy, leading to a smooth optical pulse. For different settings of the undulator the measured pulse shape and corresponding power spectrum are discussed. It is possible without decreasing the small-signal gain to produce a smooth high-power optical pulse during the whole saturated part of the machine pulse in an FEL oscillator with a reverse-step tapered undulator     

MARX发生器在脉冲雷达发射机中的应用

作为一种高压高功率脉冲源,MARX发生器已经在一些领域得到了广泛应用。文中首先将典型的MARX发生器与常用的高压脉冲调制器在性能方面进行了比较,认为该技术在脉冲雷达发射机中也有应用价值;然后,对电感隔离MARX发生器电路进行了详细分析,并重点讨论了该电路在改变脉冲宽度和改变重复频率时的工作状态,给出了在脉冲雷达发射机中应用时的优选工作模式;最后,在一部X波段中频相参脉冲多普勒天气雷达发射机中进行了尝试,获得了满意的结果。     

呼吸脉冲锁模的光子晶体光纤飞秒激光器

报道了一种掺Yb偏振型大模场面积光子晶体光纤(LMA-PCF)飞秒激光器。作为增益介质的光子晶体光纤的单模场面积比传统光纤高一个数量级,有效地降低了非线性系数,使激光器获得高能量输出。激光器基于线形腔结构,利用半导体可饱和吸收镜实现自启动锁模。光纤激光器利用光栅对进行腔内色散补偿,使其运转在呼吸脉冲锁模状态,即在谐振腔的零色散点附近实现锁模。当腔内净色散呈反常色散时,激光器获得了平均功率为400mW,重复频率为47MHz(对应于8.5nJ的单脉冲能量),脉冲宽度为500fs的稳定的锁模脉冲输出,经腔外色散补偿,脉冲压缩至98fs。当腔内净色散呈正常色散时,激光器输出的单脉冲能量为10.6nJ,脉冲宽度为1.76ps,经腔外色散补偿,脉冲压缩至160fs。     

Phase Lock for Correlation Detection of a Periodic Pulse

The detection of the presence of a periodic pulse with uncertain pulse rate and low duty cycle is a common biotelemetry problem. Modern phase-lock and correlation techniques have provided more efficient means of making the presence decision than that provided by energy detection methods. A local signal is cross correlated with the input in a phase-locked loop (PLL) to provide phase reference. Upon lock, a local duplicate signal is generated and correlated with the input. A decision threshold operates on the correlator output. The PLL with filter F(s) = (s+a)/s and three appropriate nonlinearities are analyzed for acquisition time and maximum frequency error that will lock.     

OC-192 transmitter and receiver in standard 0.18-/spl mu/m CMOS

This paper presents the first fully integrated SONET OC-192 transmitter and receiver fabricated in a standard 0.18-/spl mu/m CMOS process. The transmitter consists of an input data register, 16-b-wide first-in-first-out (FIFO) circuit, clock multiplier unit (CMU), and 16:1 multiplexer to give a 10-Gb/s serial output. The receiver integrates an input amplifier for 10-Gb/s data, clock and data recovery circuit (CDR), 1:16 demultiplexer, and drivers for low-voltage differential signal (LVDS) outputs. An on-chip LC-type voltage-controlled oscillator (VCO) is employed by both the transmitter and receiver. The chipset operates at multiple data rates (9.95-10.71 Gb/s) with functionality compatible with the multisource agreement (MSA) for 10-Gb transponders. Both chips demonstrate SONET-compliant jitter characteristics. The transmitter 10.66-GHz output clock jitter is 0.065 UI/sub pp/ (unit interval, peak-to-peak) over a 50-kHz-80-MHz bandwidth. The receiver jitter tolerance is more than 0.4 UI/sub pp/ at high frequencies (4-80 MHz). A high level of integration and low-power consumption is achieved by using a standard CMOS process. The transmitter and receiver dissipate a total power of 1.32 W at 1.8 V and are packaged in a plastic ball grid array with a footprint of 11/spl times/11 mm/sup 2/.