Over-30-GHz limiting amplifier ICs with small phase deviation foroptical communication systems

For a high-speed limiting amplifier with small phase deviation, a new design technique using a uniplanar passive balun and a narrow-band matching network is proposed. It is revealed that a device with small bias-dependence of parasitic capacitances, such as a high electron mobility transistor (HEMT), and a differential operation using passive baluns enables phase deviations at very high frequency to be reduced. Furthermore, suppressing harmonics can reduce phase deviation in a limiting amplifier, which operates in the highly nonlinear region. To verify these design techniques, two types of limiting amplifier ICs using an InP HEMT and AlGaAs/GaAs BCT technology were designed and fabricated. These IC's feature narrow-band matching circuits for input and output using transmission lines and uniplanar CPW-slot transition baluns for differential signals. The devices achieved high frequency operation of over 30 GHz with small phase deviations     

An antiresonant Fabry-Perot saturable absorber for passivemode-locking fabricated by metal-organic vapor phase epitaxy and ionimplantation design, characterization, and mode-locking

We have fabricated GaAs-based antiresonant Fabry-Perot saturable absorbers (A-FPSAs) for passive mode-locking near infrared solid-state lasers using metal-organic vapor phase epitaxy (MOVPE) growth followed by ion implantation and optional thermal annealing. We present differential reflectivity measurements showing the effect of ion implantation and annealing. The devices were characterized for their large-signal response including saturation fluence, modulation depth, and nonbleachable losses-important parameters for passive mode-locking. Finally, we demonstrate mode-locking using our samples within a Ti:sapphire laser observing stable and reliable self-starting, pulses in the 100-fs range, and 50-nm tunability. Results of computer simulations are in good agreement with the experiments     

保偏光纤无源器件

随着保偏光纤制造工艺的成熟和性能的提高，保偏光纤的应用日益扩大。特别是在干涉型传感器等测量方面，利用保偏光纤的光无源器件起非常重要的作用，且种类很多。关于保偏光纤无源器件全面和系统的论述，至今报道的不多。本文就各种保偏光纤无源器件的工作原理、性能和制作方法进行了详细的论述。所阐述的保偏光纤无源器件有：保偏光纤耦合器、偏振分束器、保偏光纤偏振器、波分复用器、消偏器、波长板等。     

干涉式被动亚毫米波成像系统

干涉式辐射计通过多通道间的相关运算得到被动亮温图像。对于亚毫米波段(submillimeter-wave, SMMW)相关运算对硬件系统的精度与相位稳定性提出了很高的要求。本文中,通过特殊设计的高精度SMMW器件,实现了一套基于二单元干涉仪的干涉式辐射计系统。针对该系统的自身特点,作者提出了点源目标响应定标方法来降低系统误差。系统完成后,分别进行了干涉条纹实验和点源目标成像实验。经测试,系统的线性相位误差小于2°,角分辨率优于0.57°。系统实测性能和理论分析结果一致。以上研究为今后设计高分辨率亚毫米波干涉式成像辐射计提供了重要的参考价值。     

Passive Beamforming Design for Intelligent Reflecting Surface Assisted MIMO Systems

Intelligent reflecting surfaces(IRSs)constitute passive devices,which are capable of adjusting the phase shifts of their reflected signals,and hence they are suitable for passive beamforming.In this paper,we conceive their design with the active beamforming action of multiple-input multipleoutput(MIMO)systems used at the access points(APs)for improving the beamforming gain,where both the APs and users are equipped with multiple antennas.Firstly,we decouple the optimization problem and design the active beamforming for a given IRS configuration.Then we transform the optimization problem of the IRS-based passive beamforming design into a tractable non-convex quadratically constrained quadratic program(QCQP).For solving the transformed problem,we give an approximate solution based on the technique of widely used semidefinite relaxation(SDR).We also propose a low-complexity iterative solution.We further prove that it can converge to a locally optimal value.Finally,considering the practical scenario of discrete phase shifts at the IRS,we give the quantization design for IRS elements on basis of the two solutions.Our simulation results demonstrate the superiority of the proposed solutions over the relevant benchmarks.     

Passive alignment method of polymer PLC devices by using a hot embossing technique

A novel fabrication process using a hot embossing technique has been developed for micromechanical passive alignment of polymer planar lightwave circuit (PLC) devices. With only one step of embossing, single-mode waveguide straight channels and micropedestals for passive aligning are simultaneously defined on a polymer thin film with an accuracy of /spl plusmn/0.5 /spl mu/m. This process reduces the steps for fabricating alignment structures. A fabricated polymer PLC chip and fibers are combined on a v-grooved silicon optical bench (SiOB) in a flip-chip manner. The process provides a coupling loss as low as 0.67 dB per coupling face and a cost-effective packaging solution for various polymer PLC devices.     

Quasi-optical antenna duplexers

The development of antenna duplexers for transceiving quasi-optical systems of millimeter and submillimeter wavelengths are considered for two groups of devices — passive and active action. Duplexers, using properties of quasi-optical hybrids, belong to the first group, and duplexers on the base of semiconductor or ferrite devices are included to the second group. Results of developments and investigations of considered devices in the millimeter wave range are presented.     

Efficient coupling in integrated twin-waveguide lasers usingwaveguide tapers

We demonstrate a 1.55-μm wavelength, InGaAsP-InP, twin-waveguide (TG) laser integrated with passive ridge waveguides using low-loss taper couplers. The lateral taper on the laser waveguide induces efficient resonant coupling of light between the active and passive layers. The device is fabricated using low-cost conventional photolithography and reactive ion etching of a TG structure grown by gas-source molecular beam epitaxy. This structure is suitable for integrating a variety of photonic devices without requiring epitaxial regrowth     

Waveguide-Type Optical Circuit for Recognition of Optical QPSK Coded Labels in Photonic Router

In photonic label routing networks, optical recognition of optical labels is one of the key functions. We propose a passive waveguide-type device for recognition of optical coded labels. We consider quadrature-phase-shift-keying (QPSK) coded labels. The basic module of the proposed device consists of a 3-dB directional coupler, two Y-junctions, and an asymmetric X-junction. By using interference between an optical pulse of each coded bit and a identifying bit pulse, the basic module distinguishes optical phase of the QPSK signal in a self-routing fashion of the identifying bit pulse. QPSK codes consisting of plural bits can also be recognized by connecting the basic module devices in a tree structure through a phase adjustment circuit. The performance of the proposed basic module is confirmed by simulation using beam propagation method (BPM).      

Fabrication of Application Specific Integrated Passive Devices Using Wafer Level Packaging Technologies

Integrated passives have become increasingly popular in recent years. Especially wafer level packaging technologies offer an interesting variety of different possibilities for the implementation of integrated passive components. In this context, particularly the fabrication of integrated passive devices (IPDs) represents a promising solution regarding the reduction of size and assembly costs of electronic systems in package (SiP). IPDs combine different passive components (R,L ,C ) in one subcomponent to be assembled in one step by standard technologies like surface mount device (SMD) or flip chip. In this paper, the wafer level thin film fabrication of integrated passive devices (WL-IPDs) will be discussed. After a brief overview of the different possibilities for the realization of IPDs using wafer level packaging technologies two fabricated WL-IPDs will be presented. Design, technological realization, as well as results from the electrical characterization will be discussed.     

温度场对实芯光子晶体光纤的影响分析

光子晶体光纤可广泛用于光纤通信系统、光电信号检测等有源和无源光器件中.利用Edlen公式分析了温度场对实芯光子晶体光纤的空气孔折射率的影响并应用热传导模型对光子晶体光纤石英介质在温度场作用下产生的热应力及折射率分布变化进行了分析,讨论了温度场变化导致光子晶体光纤中光脉冲相位和模式双折射的波动影响.与传统单模光纤相比光子晶体光纤中传播的光脉冲对温度具有较弱的敏感特性,在光电信号检测等无源器件中更具优越性.     

压力作用对实芯光子晶体光纤特性影响分析

为了能使光子晶体光纤用于光纤压力传感器等无源器件中,采用弹光理论分析方法对压力作用下光子晶体光纤纤芯和包层中应力、横向结构和折射率分布的变化进行了理论分析和实验模拟,获得了压力作用下对光子晶体光纤中传播光脉冲的相位和模式双折射的影响的数据,采用相干干涉测量技术方法能测量光子晶体光纤中光脉冲相位和模式双折射的波动量值并进一步推算出作用在光子晶体光纤上的外界压力变化量。结果表明,光子晶体光纤可用作光纤压力传感器中的敏感元件。这一结果对光子晶体光纤在光纤压力传感器中的进一步应用是有帮助的。     

Toward Improved Control of Medium Wave Directional Arrays

Relatively few types of variable power division circuits have been used in medium wave directional antenna feed systems, most of which suffer phase variation as the power division is adjusted. This paper discusses a class of circuits which can be used to implement a phase invariant adjustable power divider. Also discussed are variable phase shifters which have limited effect on power distribution. These features can simplify the original tuning and possible periodic maintenance. A computer analysis of the probable performance of such devices is presented. The associated problem of system analysis is discussed, particularly the inclusion of the effects of the antenna element coupling. To this end a lumped passive element model for a generalized linear reciprocal N port is presented.     

光无源器件产业的发展和扩建的建议

简述了光无源器件的发展趋势，分析了市场的需求情况，认为天津市在发展光无源器件的产业方面具有一定的优势和基础，据此提出了发展和扩建天津无源光器件产业的建议。     

An ultra low power consumption millimeter-wave voltage controlled oscillator in a 65 nm CMOS-SOI technology

This paper presents an ultra low power consumption 65 GHz LC-VCO dedicated to wireless high data rate applications. It is designed in a 65 nm CMOS SOI process, which improves passive devices behavior. The proposed VCO achieves a frequency tuning range (FTR) of 9.7 % and a phase noise of ?110.86 dBc/Hz at 10 MHz of the carrier. All integrated passive components (including transmission lines and a transformer-based balun) are modeled using advanced electromagnetic (EM) field solvers. The power consumption of the proposed VCO is as low as 1.1 mW when biased by a 0.8-V supply voltage. The FoM of this millimeter wave circuit, whose core occupies a silicon footprint of only 0.047 mm², is ?184.07 dBc/Hz.     

A low-phase noise injection-locked quadrature voltage-controlled oscillator

This article presents a low-phase noise quadrature voltage-controlled oscillator (QVCO) in which the re-filtering technique of the side-band noise is adopted. In the proposed QVCO, besides using re-filtering technique, the passive elements replaced the noisy and lossy active coupling devices. Therefore, due to the elimination of the associate noise sources of the active coupling devices and re-filtering of side-band noise of the circuit, the proposed QVCO shows an excellent phase-noise and FOM. The proposed QVCO was implemented and simulated in TSMC 0.18 μm RF-CMOS technology. The phase noise of the proposed QVCO at 3 MHz offset frequency from the 3 GHz center frequency is ?144 dBc/Hz, for a current consumption of 11.5 mA at a power supply of 1.8-V. Simulation results show the proposed QVCO can operate with power supply as low as 0.6 V. Monte–Carlo analyses for, 3% device mismatch and process variation, result in phase error lower than 0.8°. Generalizing the proposed coupling technique to several core VCOs very low-phase noise multiphase signals can be generated.     

光无源器件技术发展综述（续）

5　光开关当今世界各国都在研究和开发以 DWDM为基础的全光网络。全光网络的迅速发展将带来通信网的一场新的革命 ,人们将有望通过全光器件实现信息无瓶颈的高速传输。光开关是光交换机的核心元件 ,在全光网络中 ,高密度光开关矩阵能够完成开关、路由以及主要网络中枢的交叉连接的任务 ,许多光纤干线、各个载波多路光信道都可以端接 ;光开关已向智能型光开关发展 ,进入密集波分复用光网 ,简化复杂的全光网络系统。随着人们对光开关的材料、器件原理与加工工艺认识的不断深入 ,研究光开关阵列的类型也呈多元化发展趋势。已报道的光开关如按…     

A Passive Authentication System Based on Optical Variable Nano/Micro-Structures

A new optical authentication and security system using optical variable nano/micro-structures (OVNs) is presented. The proposed design features a passive authentication method using a simple optical system found in common fabrication facilities. The passive authentication is obtained by insertion of an OVN image directly on a processing layer or divided between multiple layers of the fabrication process. Authentic fabrication process is validated when the proper alignment (reconstructed image, for example) at the end of the fabrication is achieved. Simple proof-of-concept devices with the OVN-based authentication system are presented along with the optical images of the resulting authentication patterns.     

RF characterization and isolation properties of mesoporous Si by on-chip coplanar waveguide measurements

We report on the broadband electrical characterization of thick mesoporous silicon layers used as RF microplates for on-chip integration of high-Q passive devices in a CMOS-compatible process. To measure the RF losses of the microplate we have fabricated several designs of Coplanar Waveguides (CPWs), for form-factors relevant to the sizes of on-chip passive RF devices, on thick mesoporous Si layers (RF microplates) of various thicknesses, and we compared the results with those obtained from similar CPWs integrated directly on the p-type Si substrate. For maximum measurement sensitivity of the loss, the CPWs were designed to be very good transmission lines matched to 50 Ω port impedances. We also characterized the grown mesoporous Si by performing electromagnetic simulations of the structure and identifying the measured and simulated S-parameters over a broadband frequency region, for the appropriate simulator input of complex permittivity. The measured results show that, for CPW features commensurate with the scale of on-chip RF passive devices, a 50-μm-thick mesoporous Si layer on the Si substrate reduces the losses to 1/6th–1/4th of the values corresponding to a p-type Si substrate, showing that mesoporous Si is an excellent material for CMOS-compatible on-chip integration of high-Q passive devices.     

Reliable Networks Based on General Passive Routing Devices

Survivable passive network architectures based on interconnecting a small number of arrayed waveguide gratings (AWGs) have been described in prior work. Such networks are desirable for communication between a small number of users in environments that are susceptible to a high rate of failure and where providing power in the network core is difficult. In this paper, it is shown that these network designs can be improved if passive devices that have routing properties different from those of standard AWGs are considered. Devices with routing matrices represented by Latin squares and devices with more arbitrary routing patterns are considered here. This illustrates that developing the capability of manufacturing more general passive routing devices is a worthwhile goal.