Compact transmitter and receiver modules with optoelectronic-integrated circuits for optical LAN's

Compact transmitter and receiver modules with monolithic optoelectronic-integrated circuits, i.e., OEIC's, are demonstrated, and 400- and 800-Mbit/s transmission experiments are successfully carried out over up to 4 and 2 km, respectively, with these modules, for the first time. The design of the monolithic-integrated circuits and the compact module structure are presented. The soldering technique based on the use of YAG laser simplifies the packaging procedures, and an efficient and simple scheme for coupling between OEIC's and fibers make the OEIC modules compact. Both modules are attractive for applications in high data-rate communication systems, particularly in local area networks, CATV systems, and intra-office links.     

Embedded TiNxOy thin-film resistors in a build-up CSP for 10 Gbps optical transmitter and receiver modules

Integral passive components provide efficient circuit miniaturization while maintaining high performance and reducing assembly costs. The development of practical integral passive components, however, requires advances in the areas of materials, low-cost processes, and structural design. We have developed new TiNxOy thin-film resistors, as well as a termination resistor-embedded CSP, and a process for fabricating integral passive components. Our TiNxOy films exhibit a sheet resistivity in the range of 30-5k /spl Omega//square. To keep costs low, we have made the fabrication process compatible with that for MCM-D/L. Resistors as small as 25 /spl mu/m square have been successfully produced with this process. The chip scale package (CSP) with embedded resistors has been designed for 10 Gbps optical transmitter and receiver modules. A fabricated version shows excellent return loss for its termination resistor, less than -20 dB in the frequency range of 50 MHz-14 GHz, and its resistors showed high reliability in constant voltage stress tests, with less than 5% change in resistance at 800 mW/mm/sup 2/ over 1000 hours.     

用于计算机光互连的集成化发送器和接收器

从对计算机光互连的实用要求出发，实现了用集成化的发送器和接收器经光纤连接器组成收发对后，能很好地在４×４多处理机系统内用光互连代替电互连。着重探讨了发送器和接收器的结构、设计，以及工艺改进途径，对互连器件的配套选择、性能测试作了一定工作，使之能方便使用。     

Compact 10-Gbit/s optical transmitter and receiver circuit packs

Compact wideband 10-Gbit/s optical transmitter and receiver circuit packs are realized using high speed analog and digital GaAs IC's as well as a highly thermally conductive board and appropriately designed small function block modules that employ multichip packaging and resonant cavity mode damping. To achieve a compact receiver, the receiver circuit employs a clamp and peak-detector IC in the high speed analog equalizer amplifier to obtain a constant output direct current level for any mark density imbalance in the number of ones and zeros in the signal and a variable phase-shifter IC in the timing circuit. Realized circuit pack size is 200×280×15.24 mm and the power consumption of each pack is about 25 W     

2.5 Gbit/s光发射模块消光比与光接收误码特性

改变2．5Gbit/s光发射模块消光比（EX）,对作为标准接收用的光接收机灵敏度进行了测试。实验表明,EX小于9．0时,光接收灵敏度较差;EX大于15．0时,由于眼图中交叉点偏低或光脉冲波形畸变,可能导致光接收灵敏度恶化;EX在9．0－12．0范围时,光接收灵敏度最佳。     

消光比对10Gb/s光接收模块灵敏度的影响

10Gb/s光通信用光接收模块前端常采用APD-TIA组件.理论表明,具有该组件的10Gb/s光接收模块的光灵敏度,主要取决于光纤耦合效率、APD偏置电压、光倍增、过剩噪声和暗电流和消光比等.测试表明,当其它相关因素不变,消光比由5.0dB变到11.0dB时,光接收灵敏度发生2.0～5.0dBm的优化,指出了获得较佳光...     

GE-PON用光收发模块应力接收灵敏度探讨

介绍了GE-PON用光接收模块应力接收灵敏度相关的国际标准、技术指标和测量原理,报告了10光收发模块的应力接收灵敏度的实测结果,讨论了应力接收灵敏度测试的代价和类似标准的差异.     

Smart optical receiver with automatic decision threshold settingand retiming phase alignment

The requirements for a smart optical receiver are discussed, and a design architecture suitable for introducing ICs based on automatic decision threshold setting and retiming phase alignment using digital/analog signal processing feedback is proposed. With the proposed architecture, the decision threshold level and the retiming clock phase of received data in the decision circuit are automatically adjusted to the optimum position. This obviates the need for decision threshold level and retiming clock phase adjustments in production testing, and it reduces the power penalty (receiver sensitivity degradation) on the received optical waveform variation. The power penalty caused by temperature and supply-voltage variations and aging in installation is also reduced. The performance of the proposed architecture is estimated; the power penalty as compared with the manual optimum adjustment is less than 0.4 dB, and the robustness to avalanche photodiode multiplication factor variations and crosstalk are improved     

A low-power 2.4-GHz transmitter/receiver CMOS IC

A 2.4-GHz CMOS receiver/transmitter incorporates circuit stacking and noninvasive baseband filtering to achieve a high sensitivity with low power dissipation. Using a single 1.6-GHz local oscillator, the transceiver employs two upconversion and downconversion stages while providing on-chip image rejection filtering. Realized in a 0.25-/spl mu/m digital CMOS technology, the receiver exhibits a noise figure of 6 dB and consumes 17.5 mW from a 2.5-V supply, and the transmitter delivers an output power of 0 dBm with a power consumption of 16 mW.     

On transmitter gain/phase imbalance compensation at receiver

This letter explores the benefits of compensating for transmitter gain and phase imbalances in a receiver for quadrature communication systems. It is assumed that the gain and phase imbalances are introduced at the transmitter only. The Gram-Schmidt orthogonalization procedure is used at the receiver to compensate for the imbalances. Computer simulation has been performed to study a coherent differential QPSK communication system. It has been found that the bit error rate performance is improved significantly if the transmitter phase imbalance is compensated for. However, no improvement can be obtained if the transmitter gain imbalance is compensated for     

Front/back tracking InGaAsP diode laser transmitter modules

Variations in the detected power for movement of a single-mode and a multimode fiber in front of various 1.3-μm InGaAsP diode lasers are measured and compared to the signal obtained from the back-facet monitor. A model to explain the nonlinear relationship between the detected front and back-facet powers is given. This work has application in the design and understanding of stable light sources, biasing of transmitter modules, the fiber attach process, and the interpretation of tests which check the integrity of the fiber attachment     

Joint transmitter receiver diversity for efficient space divisionmultiaccess

The beamforming problem is studied in wireless networks where both the transmitters and receivers have linear adaptive antenna arrays. Algorithms are proposed that find the antenna array weight vectors at both the transmitters and receivers as well as the transmitter powers with one of the following two objectives: (1) to maximize the minimum signal-to-interference-and-noise ratio (SINR) over all receivers and (2) to minimize the sum of the total transmitted power satisfying the SINR requirements at all links. A numerical study is performed to compare the network capacity and the power consumption among systems having a different number of antenna array elements in a code division multiple access network     

Iterative transmitter and receiver optimization for CDMA networks

Optimization of the capacity of a single-cell code-division multiple-access (CDMA) system, both from the perspective of the maximum number of users that can be served at a required quality of service level and from the information theoretic perspective, has been recently shown to be achieved by the same joint transmit and receive strategies. We propose an alternating minimization based iterative algorithm that updates the transmitters and the corresponding receivers of the users. The algorithm is suitable for online implementation, and the objective function is suitable for extension to multicell networks, both of which are in contrast with the previously proposed algorithms. We show that the algorithm is provably convergent to the optimum signature sequences and the corresponding receivers.     

Low-noise optical receiver for high-speed optical transmission

This paper describes the design of a low-noise optical receiver using Si bipolar transistors for high-speed optical transmission. The conventional common emitter-common collector circuit (CE-CC pair) and Darlingtou circuit (transimpedance amplifiers with parallel feedback) are studied. Optimal CE-CC pair collector-biasing current for attaining minimum noise current with a 400-MHz bandwidth is 2.7 mA, and less than 1.2 mA for the Darlington circuit. It is confirmed that the Darlington circuit is better than the CE-CC pair in signal-to-noise ratio by about 1.5 dB. The low-noise Darlington optical receiver with a Ge-avalanche photodiode has achieved an optical sensitivity of -41 dBm for a 400 Mbit/s RZ pulse with a bit error rate of 10^-10. This is a 2.5-dB improvement in optical sensitivity over that of the conventional CE-CC receiver.     

Si-analog IC's for 20 Gb/s optical receiver

Two Si-Analog IC's, a preamplifier IC and a decision IC, for a 20 Gb/s optical receiver have been developed using SiGe-base bipolar transistors having a 60 GHz maximum cutoff frequency. The preamplifier employing a dual feedback loop increases the -3 dB bandwidth up to 19 GHz. A decision IC, composed of a gain controllable amplifier with a bias stabilization circuit and D-F/F, operated at up to 20 Gb/s with a 200-mVp-p input sensitivity     

Optimum transmitter/receiver design for a narrowband overlay in noncoordinated subscriber lines

Transmitter/receiver optimization for a generic narrowband overlay communication scenario is addressed. The overlay and existing legacy systems are assumed to occupy the same frequency bands for spectral efficiency, thus introducing cochannel interference; however, the new and legacy systems are assumed to be noncooperative, as is appropriate for some pragmatic scenarios. A composite figure of merit is used consisting of a weighted sum of the mean-squared error (MSE) of the (new) overlay system plus the excess MSE in the legacy system caused by the introduction of the overlay system. Necessary conditions on the transmitter and receiver that jointly optimize the above metric are derived. The effects of varying key parameters such as the loop length (range) and transmitter power are investigated via computational examples.     

Low-noise optical receiver for high-speed optical transmission

This paper describes the design of a low-noise optical receiver using Si bipolar transistors for high-speed optical transmission. The conventional common emitter-common collector circuit (CE-CC pair) and Darlington circuit (transimpedance amplifiers with parallel feedback) are studied. Optimal CE-CC pair collector-biasing current for attaining minimum noise current with a 400-MHz bandwidth is 2.7 mA, and less than 1.2 mA for the Darlington circuit. It is confirmed that the Darlington circuit is better than the CE-CC pair in signal-to-noise ratio by about 1.5 dB. The low-noise Darlington optical receiver with a Ge-avalanche photodiode has achieved an optical sensitiyity of -41 dBm for a 400 Mbit/s RZ pulse with a bit error rate of 10^-10. This is a 2.5-dB improvement in optical sensitivity over that of the conventional CE-CC receiver.     

实用化565Mbit／s光发送机

本文介绍实用于565Mbit/s速率上的光发送机,并叙述其工作性能及指标。