10‐Gbit/s Wireless Communication System at 300 GHz

A 10‐Gbit/s wireless communication system operating at a carrier frequency of 300 GHz is presented. The modulation scheme is amplitude shift keying in incoherent mode with a high intermediate frequency (IF) of 30 GHz and a bandwidth of 20 GHz for transmitting a 10‐Gbit/s baseband (BB) data signal. A single sideband transmission is implemented using a waveguide‐tapered 270‐GHz highpass filter with a lower sideband rejection of around 60 dB. This paper presents an all‐electronic design of a terahertz communication system, including the major modules of the BB and IF band as well as the RF modules. The wireless link shows that, aided by a clock and data recovery circuit, it can receive 2⁷?1 pseudorandom binary sequence data without error at up to 10 Gbit/s for over 1.2 m using collimating lenses, where the transmitted power is 10 μW.     

60GHz全双工OFDM-ROF系统的实验研究

研究了基于光外部调制的方式产生60GHz光毫米波的全双工光纤无线(ROF)通信系统。实验利用29GHzRF源产生58GHz的光载毫米波,2.5Gbit/s OFDM信号作为下行数据信号调制到光载毫米波上并传输光纤20km,在基站与用户单元实现3.3m的无线传输。同时实现了下行信号中心载波重利用作为上行信号的光载波,2.5Gbit/s的OOK信号作为上行数据信号调制到光载波上经20km上行链路光纤传输至中心站。     

Recovery of 80 GHz optical clock from 160 Gbit/s data using regeneratively modelocked laser diode

An 80 GHz optical clock signal was successfully recovered from a 160 Gbit/s data stream using a regeneratively modelocking scheme of a semiconductor modelocked laser (MLLD). To handle an 80 GHz electrical signal, the MLLD integrated with a high-mesa electroabsorption modulator and a W-band UTC-PD module are used in this scheme.     

40 Gbit/s differential distributed modulator driver realised in 80 GHz SiGe HBT process

A 40 Gbit/s, fully differential distributed SiGe HBT driver is presented. The IC is realised in a low-cost 80 GHz production process, and is intended to operate as a modulator driver in a 40 Gbit/s fibre-optic communication system. Resulting from the differential chip architecture, no off-chip low-frequency transmission line termination networks are required, which significantly alleviates the chip mounting process. Mounted in a coaxial test fixture, an eye opening of 2 1.25 V_pp at 40 Gbit/s operation is measured.     

11 GHz ultrawide-bandwidth monolithic photoreceiver using InGaAspin PD and InAlAs/InGaAs HEMTs

A very-wide-bandwidth long-wavelength monolithically integrated photoreceiver is presented which comprises an InGaAs pin PD and a transimpedance amplifier. The receiver uses epilayers grown by one-step MOVPE. The InGaAs channel high-electron-mobility field effect transistor (HEMT) employs an Si planar-doped carrier supplying layer to obtain larger transconductance and uniform threshold voltage. The 0.5 μm gate length is used for HEMTs to enhance the speed of operation. This receiver shows a very wide bandwidth of 11 GHz, and opened eye for a 15 Gbit/s NRZ signal. This is the first demonstration of a long-wavelength monolithic photoreceiver receiving a 15 Gbit/s light signal     

9.7 GHz small-signal bandwidth of three-quantum well GaInNAs/GaAs laser diodes operating at 1.35 /spl mu/m

High frequency characterisation of three-quantum well GaInNAs/GaAs lasers operating at 1.35 /spl mu/m is reported. A relaxation frequency as high as 7.4 GHz and a 9.7 GHz small-signal bandwidth are demonstrated, indicating the potential for high bit rate (10 Gbit/s) direct modulation of these dilute nitrides on GaAs devices.     

Design of 10 GHz eight-phase voltage controlled oscillator in 90 nm CMOS

A novel 10 GHz eight-phase voltage-controlled oscillator(VCO) architecture applied in clock and data recovery(CDR) circuit for 40 Gbit/s optical communications system is proposed.Compared with the traditional eight-phase oscillator,a new ring CL ladder filter structure with four inductors is proposed.The VCO is designed and fabricated in IBM 90nm complementary metal-oxide-semiconductor transistor(CMOS) technology.Measurement results show the tuning range is 9.2 GHz～11.0 GHz and the phase noise of-108.85 dBc/Hz at 1 MHz offset from the carrier frequency of 10 GHz.The chip area of VCO is 500 μm× 685 μm and the power dissipation is 17.4 mW with the 1.2 V supply voltage.     

A novel scheme to generate multiband millimeter wave signals for 40 GHz full duplex radio-over-fiber system

This paper proposes a new scheme to generate frequency-diversity binary phase shift keying (BPSK) signals for radio-over-fiber (RoF) system. As is well known, the frequency diversity technology has the anti frequency selective fading characteristic and RoF system is a practical solution to increase the capacity and mobility of future-proof contents delivery and serve both fixed and mobile users. In this paper, our proposal can generate 20 GHz and 40 GHz millimeter-wave (mm-wave) signals simultaneously with the data rate of 1.25 Gbit/s employing only one electrical optical phase modulator (EOPM) and one Mach-Zehnder modulator (MZM) at the central station. With one additional MZM at the base station, the full duplex transmission can be accomplished. As the downstream data is phase modulated, the optical signal can be re-used to load the upstream data and no laser diode (LD) is needed at the base station, which simplify the structure of the base station. The 20 GHz electrical carrier is also generated which can be used to demodulate the BPSK signal. The whole scheme can be used in the future duplex RoF system.     

10 GHz optical receiver using a travelling-wave semiconductor laser preamplifier

A 1.5 ?m optical receiver with a bandwidth of 10 GHz has been demonstrated. The receiver used a travelling-wave semiconductor laser preamplifier and had an equivalent input noise of 1 pA/?Hz) with a 3 dB bandwidth of 10 GHz. The estimated sensitivity at 15 Gbit/s was ?27 dBm.     

全光纤波分复用传输系统实验研究

本文报道了一种新颖的波分复用系统－全光纤集成型系统：光发射机由全光纤激光器构成，光传输过程中各节点的上／下载由光纤光栅ADM承担，传输中继则由掺饵光纤放大器完成，在这一全光纤系统上，首次成功地实现了1．2Gbit/s的非归零码、1．2Gbit/s的归零码和2．5GHz、5GHz的模拟信号经100km的传输和下载。     

Theoretical model of optical fiber secure communication system with chaotic multiple-quantum-well lasers

Chaotic synchronization of injected multiple-quantum-well lasers of optical fiber system and a theoretical model of optical fiber chaotic secure communication system are presented by coupling a chaotic multiple-quantum-well laser synchroniza- tion system and a fiber channel. A new chaotic encoding method of chaos phase shift keying On/Off is proposed for optical fiber secure communications. Chaotic synchronization is achieved numerically in long-haul fiber system at wavelength 1.55 μm. The effect of the nonlinear-phase of fiber is analyzed on chaotic signal and synchronization. A sinusoidal signal of 0.2 GHz frequency is simulated numerically with chaos masking in long-haul fiber analog communication at wavelength 1.55 μm while a digital signal of 0.5 Gbit/s bit rate is simulated numerically with c1haos masking and a rate of 0.05 Gbit/s are also simulated numerically with chaos shift keying and chaos phase shift keying On/Off in long-haul fiber digital communica- tions at wavelength 1.55 μm     

W波段高速远距离无线实时通信

由于高频和宽频带的特性,W波段毫米波可支持高速率、远距离无线传输,在未来无线通信中是一项很有前景的技术。为研究W波段毫米波的无线传输特性,建立了W波段无线信道模型,进行链路分析,并基于光生毫米波技术进行了实验研究。结果显示,可以成功搭建1.485 Gb/s, 90 GHz的W波段实时通信系统,并成功实现了高清无压缩视频无线传输265 m。迄今为止,这是高清视频信号在W波段实时无线传输的最远距离。     

40 Gbit/s/GHz clock recovery and frequency multiplyingAlGaAs/GaAs-HEMT-IC using injection-synchronised narrowband ring-VCOsand auxiliary PLLs

An IC technique for clock recovery and frequency multiplication was developed by combining a preprocessor, an injection-synchronised narrowband ring voltage controlled oscillator, and a phaselocked loop. A 40 Gbit/s/GHz IC was realised using 0.2 μm GaAs HEMTs. A multiplying factor as high as 64 was reached. The DC consumption is 900 mW     

Ultra-compact 350 GHz gain-bandwidth product 40 Gbit/s predriver IC in SiGe bipolar technology

An ultra-compact 0.36 mm/sup 2/ differential wideband amplifier fabricated using SiGe technology is presented. Measurements show an on-wafer gain of 20.8 dB and a 3 dB cutoff frequency of 32.0 GHz. The mounted amplifier's gain is 19.5 dB. The circuit is intended to operate as a predriver in a 40 Gbit/s fibre-optic communication system.     

基于宽谱光源OFDM信号传输技术

提出了一种新型的基于ASE宽谱光源的OFDM传输技术,该技术实现了3.0 GHz带宽、1 GHz带宽、16QAM、512个载波、速率2 Gbit/s的OFDM信号20 km以内无误码传输。对系统的矢量信号特性EVM和系统工作点的关系也进行了讨论。     

基于相位调制器倍频技术产生56GHz毫米波的光载无线通信系统

提出并实验研究了一种基于光相位调制器(PM)倍频技术产生56GHz毫米波的光载无线通信(RoF)系统。在中心站,通过28GHz射频(RF)信号驱动PM产生了56GHz光毫米波,并将下行的2.8Gb/s开关键控(OOK)信号调制到该光载波上,然后经过20km标准单模光纤(SSMF)传输至基站,最后由天线进行发射。用户终端接收后,采用相干解调恢复出基带信号。实验结果表明,56GHz光载毫米波信号经SSMF传输20km后其功率代价小于1dB,通过无线方式传输1.1m后其功率代价小于2.5dB。     

8 Gbit/s wireless data transmission at 250 GHz

8 Gbit/s wireless data transmission using a 250 GHz millimetre-wave carrier signal is demonstrated. Photonic devices and technologies, including an electro-optic modulator and J-band uni-travelling-carrier photodetector (UTC-PD) module, were used for the transmitter. In addition, a high-efficiency Schottky barrier diode detector monolithically integrated with a ring slot antenna was developed and fabricated for the receiver on the same epi-layer as the UTC-PD.     

A 77 GHz mHEMT MMIC Chip Set for Automotive Radar Systems

A monolithic microwave integrated circuit (MMIC) chip set consisting of a power amplifier, a driver amplifier, and a frequency doubler has been developed for automotive radar systems at 77 GHz. The chip set was fabricated using a 0.15 µm gate‐length InGaAs/InAlAs/GaAs metamorphic high electron mobility transistor (mHEMT) process based on a 4‐inch substrate. The power amplifier demonstrated a measured small signal gain of over 20 dB from 76 to 77 GHz with 15.5 dBm output power. The chip size is 2 mm × 2 mm. The driver amplifier exhibited a gain of 23 dB over a 76 to 77 GHz band with an output power of 13 dBm. The chip size is 2.1 mm × 2 mm. The frequency doubler achieved an output power of –6 dBm at 76.5 GHz with a conversion gain of ?16 dB for an input power of 10 dBm and a 38.25 GHz input frequency. The chip size is 1.2 mm × 1.2 mm. This MMIC chip set is suitable for the 77 GHz automotive radar systems and related applications in a W‐band.     

采用两个级联外部调制器产生四倍频光载毫米波的光纤无线通信系统

研究了一种采用两个级联外部调制器基于光载波抑制原理产生四倍频毫米波的光纤无线通信(ROF)系统.在中心站利用电混频器产生副载波复用信号,通过第一个外部调制器产生两倍射频(RF)信号的光载毫米波信号,再通过第二个外部调制器产生四倍射频信号的光载毫米波.实验显示采用频率为10 GHz的射频信号源和2.5 Gbit/s的数据基带信号混频通过两个级联外部凋制器后产生毫米波的频率为40 GHz,并且在单模光纤中传输距离达20 km,功率代价小于2 dB.     

Optical transmission using PSK-modulated subcarriers at frequencies to 16 GHz

The use of a 1.3 ?m InGaAsP constricted mesa laser to transmit microwave subcarriers at frequencies from 3 GHz to 16 GHz is described. The subcarriers are phase-modulated at 2 Gbit/s and the error rate is measured for transmission over 34 km. The effect of laser intensity noise on the system transmission is described.