Coupling of NRD-Guide Filled with Low Permittivity Dielectric Between Waveguides

A new version of NRD-guide coupling structure is proposed in which a low permittivity dielectric is filled between the coupling waveguides. It takes full advantage of the common NRD-guide with more flexibility. The choice of different dielectric materials can optimize the required performance. The corresponding coupling characteristics are analyzed. Some examples are given to show the new coupling characteristics. An important feature is the enhanced coupling between the waveguides and increased attenuation in the transverse direction, and this implies a size reduction and enhanced EMC capability. Furthermore, the filling of the low dielectric material between the coupling waveguides makes the structure an integrated unit and especially suitable for realization by micro-electromechanical system (MEMS) or by microwave integrated circuits.     

VCSELs with monolithic coupling to internal horizontal waveguides using integrated diffraction gratings

A VCSEL structure with output coupling to an internal waveguide using integrated diffraction gratings has been demonstrated. The design and fabrication of the monolithically integrated structure, including epitaxial regrowth, is discussed and initial device characteristics are presented. While horizontal waveguides can be used to route optical signals between monolithically integrated components, a small amount of transmission is retained in the top DBR to enable on-wafer testing. This monolithic structure has the potential to enable VCSEL-based photonic integrated circuits on GaAs.     

Study of the magnetic coupling between a SQUID and wires integratedon a chip

Magnetic coupling between a SQUID and wires in an integrated circuit has been studied. Using test integrated circuits, the coupling is measured by varying the distance from the SQUID to each wire. The coupling between the SQUID and the wires with and without a groundplane decreases with an increase in the distance. The coupling for the wires with the groundplane is smaller than that for the wires without the groundplane at distances less than 595 μm. However, the rate of the decrease in the coupling for the wires with the groundplane falls off for distances more than 595 μm and the coupling converges to around 2.9 pH. From two dimensional simulations for the magnetic flux coupling, the origin of the residual inductance is found to be the coupling between the SQUID, and shielding current in the groundplane. The value of the distance, 595 μm, does not depend on the size of the SQUID. To decrease the coupling, the use of wires with stripline structure or coplanar structure is desirable     

Integrated self-scanning light-emitting device (SLED)

The fabrication of monolithically integrated self-scanning light-emitting device (SLED) on a GaAs substrate and its performance are described. The SLED consists of integrated light-emitting thyristors whose turn-on voltages interact with each other through coupling diodes or resistors. Light-emitting states are automatically transferred by input clock pulses without using external shift registers. The resistors are made of a Cr-SiO cermet film, and the coupling diodes are made in part with p-n layers of thyristors. The integrated SLED is fabricated in eight photolithographic steps. High-speed operation, more than 10 MHz, can be achieved due to its simple structure and high-density packaging. It is expected that this SLED will be a key device in future large-scale optoelectronic integrated circuits     

如何抑制直接耦合放大电路中零点漂移

直接耦合放大电路既能放大交流信号,又能放大缓变信号和直流信号,其频率特性的下限频率为零。在集成电路中,由于容量较大的电容器难以制作,因此集成放大电路一般采用直接耦合的结构。但是,直接耦合方式又给放大电路带来一个特殊的问题,这个特殊的问题就是零点漂移,在此介绍直接耦合放大电路的特点和直接耦合带来的特殊问题,根据产生这个问题的原因,讲述解决抑制零点漂移的各种措施。着重讲述利用差动放大电路抑制零点漂移的工作原理。     

Wideband two-layer SIW coupler: design and experiment

An original wideband two-layer substrate integrated waveguide directional coupler is presented. The structure provides attractive features including a flexible design with a wideband coupling and independent control of the transmission phase for arbitrary coupling levels. Characteristics of 18 dB isolation and 90 phase shift between direct and coupled ports are experimentally validated over 16 bandwidth.     

Performance improvements of interleaving VRMs with couplinginductors

The multichannel interleaving buck converter with small inductance has proved to be suitable for voltage regulator modules (VRMs) with low voltages, high currents, and fast transients. Integrated magnetic components are used to reduce the size of the converter and improve efficiency. However, the structure of the integrated magnetic requires precise adjustment and is not mechanical stable. This paper proposes integrated coupling inductors between the channels to solve these problems. With the proper design, coupling inductors can improve both the steady-state and dynamic performances of VRMs with easier manufacturing     

基于硅基IPD技术的新型S波段带通滤波器设计

将无源器件内埋或集成在封装基板中,是射频系统级封装(SIP)的小型化面临的首要问题之一.基于硅基集成无源器件(IPD)技术,借鉴经典的级联四角元件(CQ)滤波器拓扑,提出一种四电感互耦结构.利用集总LC谐振器和分布式互感耦合原理,在交叉耦合节点处以加载电容的方式引入频变耦合节点,实现了一款新颖的S波段四阶带通滤波器,尺寸仅为1.5 mm×l mm,其通带内最小插损约为-3.5 dB@ 2.8 GHz,-1 dB带宽为2.63～2.96 GHz,在带外形成两个传输零点位置:-41.5 dB@2.29 dB@3.34 GHz.该滤波器结构形式新颖,可以整体集成到硅基板中,为射频系统级封装一体化集成提供支持.     

IC compatible optical coupling techniques for integration of ARROWwith photodetector

New structures for efficient coupling of light from an antiresonant reflecting optical waveguide (ARROW) to integrated photodiode are proposed and analyzed. Both end-fire and leaky-wave types of coupling have been considered and it is found that high-coupling efficiencies can be achieved by exploiting the intrinsic properties of the ARROW structure without requiring additional non-IC compatible materials. The coupling structures were simulated using a simple ray optics model as well as the beam propagation method (BPM). Fabrication process conditions and measurement results for various coupling structures are presented     

A Low-Capacitance Multielectrode Probe for Use in Extracellular Neurophysiology

A multielectrode structure containing integrated junction-FET input stages is described. Photoengraved microelectrodes are utilized to obtain high dimensional precision, small size, and extremely low capacitive coupling between electrodes. The interelectrode capacitance is less than 0.01 pf. The integrated input devices (JFET's) reduce the impedance levels on the recording channels to less than 500 ohms, virtually eliminating crosstalk and stray noise pickup from the system. The n-channel JFET's operate as source-followers from a common 2.5 volt drain supply and have input impedances greater than 100 megohms at 1 kHz. A simple external preamplifier ensures stable operation and easy interfacing with conventional recording and display equipment. Special considerations in the design of low-noise completely integrated input stages for use with metal microelectrodes are discussed in detail. As a result of the low interelectrode coupling in this structure, simultaneous recording and stimulation from closely adjacent areas of brain should be possible with virtually no stimulus artifact.     

GaInAsP/InP integrated laser with butt-jointed built-in distributed-Bragg-reflection waveguide

A novel GaInAsP/InP integrated laser with butt-jointed built-in distributed-Bragg-reflection waveguide (BJB-DBR integrated laser for short) is proposed and demonstrated. In this structure, it is found theoretically that an efficient coupling of 98% between the active and butt-jointed external waveguides is available by matching the propagation constants and the field profiles of both waveguides, which gives relatively larger fabrication tolerance. Prototype BJB-DBR integrated lasers with emitting wavelength of 1.55 ?m were fabricated, and single-longitudinal-mode operation was obtained at room temperature.     

Enhanced Vertical Light Extraction From Ultrathin Amorphous Si–Si$_{3}$ N$_{4}$ Multilayers With Photonic Crystal Patterns

We have investigated the significant enhancement of light extraction from amorphous Si-Si₃N₄ multiple-quantum-well structures, in which two-dimensional hexagonal-lattice air-hole photonic crystals (PCs) were integrated. The vertical spectral integrated intensity of light emission around 674 nm was enhanced up to times due to strong coupling to the inherent leaky modes or radiation modes near Gamma point of PC's band structure. The experimental observations also suggested that coupling to leaky modes should be more beneficial for light extraction enhancement.     

X波段SIW广义切比雪夫超结构滤波器设计

基于基片集成波导设计了一种正交分裂环谐振器,并证明了该谐振器具有双负特性。将该超结构放置于双层基片集成波导中,得到了具有频率选择特性的四端口耦合结构。将加载正交分裂环谐振器的耦合结构与广义切比雪夫滤波器相结合,设计了一种X波段SIW广义切比雪夫超结构滤波器。仿真结果表明,设计的滤波器满足了中心频率为10.519 GHz、相对带宽为0.25%、通带内的插入损耗小于-1 dB、回波损耗小于-20 dB的技术指标。     

Measurement and Characterization of Microwave Interaction between Integrated Distributed Feedback Laser Diode and Electro-Absorption Modulator

Integrated electro-absorption-modulated distributed feedback laser diodes (EMLs) are attracting much interest in optical communications for the advantages of a compact structure, low power consumption, and high-speed modulation. In integrated EML, the microwave interaction between the distributed feedback laser diode (DFB-LD) and the electro-absorption modulator (EAM) has a nonnegligible influence on the modulation performance, especially at the high-frequency region. In this paper, integrated EML was investigated as a three-port network with two electrical inputs and a single optical output, where the scattering matrix of the integrated device was theoretically deduced and experimentally measured. Based on the theoretical model and the measured data, the microwave equivalent circuit model of the integrated device was established, from which the microwave interaction between DFB-LD and EAM was successfully extracted. The results reveal that the microwave interaction within integrated EML contains both the electrical isolation and optical coupling. The electrical isolation is bidirectional while the optical coupling is directional, which aggravates the microwave interaction in the direction from DFB-LD to EAM.     

Prismatic Coupling Structure for Intrachip Global Communication

Metal wires for global communication on integrated circuits have become problematic as device integration densities scale with rapid advancements in CMOS technology. They may not be able to deliver the growing bandwidth requirements of future microprocessors. Optical interconnect technologies may provide a solution to meet this challenge and extend Moore's law. In this paper, a novel guided-wave optical interconnect fabric aiming to replace the slow global metal interconnections is proposed and analyzed. The reflection-mode multiple-quantum-well-modulator-based optical interconnection approach is projected to achieve high coupling efficiency and be compatible with standard CMOS processes. The key notion is a prismatic coupling structure that is embedded in the optical waveguide and therefore has a very small footprint in the circuit. Ray-trace and finite-difference time-domain simulation results predict high coupling efficiency of this structure.      

基于基片集成波导（SIW）窄边耦合定向耦合器的多路功率分配/合成网络

基片集成波导（SIW）是近年来出现的一种新型传输线,随着现代LTCC技术和PCB技术的快速发展,SIW在现代微波电路中有着较好的应用前景。在此利用这种新型结构,设计了基于SIW窄边耦合定向耦合器的多路功率分配网络,实验样件的测试结果与Ansoft HFSS商用软件仿真结果吻合较好。     

薄膜解耦集成磁件的结构设计与研究

文中分析了磁件解耦集成的基本原理,得出了磁件实现解耦集成所需的基本条件;根据抵消绕组间耦合作用的方法设计了一个解耦的集成磁件,将一个小功率变压器和一个电感集成在一起;采用薄膜化技术设计制作该集成磁件的薄膜磁芯;为了消除采用传统磁件结构时磁件两端的漏磁,设计了特殊的磁芯结构和与其相配套的绕组结构;对该磁件进行了仿真研究,验证了设计的有效性和可行性。     

基于光子晶体方形谐振器的可调谐光信号分离器

在二维光子晶体结构中通过调节光子晶体方形谐振器PCSRs(Photonic Crystal Square Resonators)与波导的耦合长度、耦合宽度、及其耦合柱半径优化设计了光信号分离器.借助于CMT(Coupled-Mode Theory)理论定性分析了两个PCSRs存在相互作用时,结构中波导与谐振腔之间的电磁波耦合性能,用FDTD方法研究了两信道传输工作特性.表明在设计的参数范围中,基于PCSRs的信号分离器具有高正规化传输率、窄带宽、平稳的信号传输强度,中心波长调谐范围宽的特性.该类结构可用于同一中心波长信号的功率二等均分,也可用于不同中心波长信号的分离.该微型结构在片上的光路设计将是一类有潜力的构筑模块,适于光通信领域波分解复用设计、光路集成设计等方面.     

Substrate integrated waveguide (SIW) linear phase filter

A planar four-pole linear phase filter centered at 10GHz based on substrate integrated waveguide (SIW) is proposed. The filter is composed of four side-by-side horizontally oriented SIW cavities, which are coupled in turn by evanescent waveguide sections with three direct coupling and one cross coupling between the first and fourth SIW cavities. The SIW cavities are fed by microstrips through coupling slots. A curve-fitting technique is adopted to improve the efficiency of the design process. The measured results are presented and compared with the results simulated by a high-frequency structure simulator. Good agreement between the simulated and measured results is observed.     

Extremely high waveguide-optical amplifier coupling efficienciesmeasured on passive test structures

It is pointed out that extremely high coupling efficiencies can be achieved on passive structures which simulate an integrated waveguide amplifier. The bundle integrated guide (BIG) configuration exhibits a coupling efficiency of 95% per interface, which is in perfect agreement with the theoretical prediction. This coupling efficiency has been determined by measuring 38 monolithically integrated BIG structures