A verified equivalent-circuit model for slotwaveguide modulators

We formulate and experimentally validate an equivalent-circuit model based on distributed elements to describe the electric and electro-optic (EO) properties of travellingwave silicon-organic hybrid (SOH) slot-waveguide modulators. The model allows to reliably predict the small-signal EO frequency response of the modulators exploiting purely electrical measurements of the frequency-dependent RF transmission characteristics. We experimentally verify the validity of our model, and we formulate design guidelines for an optimum trade-off between optical loss due to free-carrier absorption (FCA), electro-optic bandwidth, and {\pi}-voltage of SOH slot-waveguide modulators

Novel Multicarrier Memory Channel Architecture Using Microwave Interconnects: Alleviating the Memory Wall

abstract: The increase in computing power has simultaneously increased the demand for input/output (I/O) bandwidth. Unfortunately, the speed of I/O and memory interconnects have not kept pace. Thus, processor-based systems are I/O and interconnect limited. The memory aggregated bandwidth is not scaling fast enough to keep up with increasing bandwidth demands. The term "memory wall" has been coined to describe this phenomenon. A new memory bus concept that has the potential to push double data rate (DDR) memory speed to 30 Gbit/s is presented. We propose to map the conventional DDR bus to a microwave link using a multicarrier frequency division multiplexing scheme. The memory bus is formed using a microwave signal carried within a waveguide. We call this approach multicarrier memory channel architecture (MCMCA). In MCMCA, each memory signal is modulated onto an RF carrier using 64-QAM format or higher. The carriers are then routed using substrate integrated waveguide (SIW) interconnects. At the receiver, the memory signals are demodulated and then delivered to SDRAM devices. We pioneered the usage of SIW as memory channel interconnects and demonstrated that it alleviates the memory bandwidth bottleneck. We demonstrated SIW performance superiority over conventional transmission line in immunity to cross-talk and electromagnetic interference. We developed a methodology based on design of experiment (DOE) and response surface method techniques that optimizes the design of SIW interconnects and minimizes its performance fluctuations under material and manufacturing variations. Along with using SIW, we implemented a multicarrier architecture which enabled the aggregated DDR bandwidth to reach 30 Gbit/s. We developed an end-to-end system model in Simulink and demonstrated the MCMCA performance for ultra-high throughput memory channel. Experimental characterization of the new channel shows that by using judicious frequency division multiplexing, as few as one SIW interconnect is sufficient to transmit the 64 DDR bits. Overall aggregated bus data rate achieves 240 GBytes/s data transfer with EVM not exceeding 2.26% and phase error of 1.07 degree or less.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Miniaturization Techniques of Substrate Integrated Waveguide Based on Multilayered Printed Circuit Board Platform

RESUMÉ Le guide d'ondes intégrées au substrat (GIS) est une structure à ondes guidées qui présente des avantages avec un facteur de qualité Q élevé et une excellente isolation ligne à ligne. La technique GIS a été largement utilisé dans la construction de composants passifs, tels que coupleurs, diviseurs, filtres, et déphaseurs. Certains dispositifs actifs ont également été développés avec facteur Q élevé et résonateurs en technologie GIS. En comparant à d'autres types de lignes de transmission planaire, le facteur de qualité Q important du GIS est une embouchure pour son intégration avec d'autres circuits classiques. Les techniques de miniaturisation du SIW sont donc devenues une urgence. Le travail dans cette thèse commence par l'examen et la discussion des techniques de miniaturisation existantes pour GIS, y compris les (ridge substrate integrated waveguide, RSIW), intégrés sur substrat à demi-mode (HMSIW) et les (folded substrata integrated waveguide, FSIW). L'impédance et la constante de propagation des lignes basées sur ces techniques de miniaturisation sont calculées en utilisant la méthode de résonance transversale (transverse resonant method, CRT). Bien que ces paramètres puissent être obtenus par des méthodes de simulation EM, un calcul rapide sera utile pour l’optimisation de la conception en utilisant l'analyse paramétrique. Une préoccupation particulière est axée sur la relation entre la constant d’atténuation et les paramètres géométriques. Les dimensions optimisées de chaque GIS miniaturisés sont proposés en se basant sur l'analyse paramétrique. Les paramètres de transmission de ces lignes de SIW miniaturisés peuvent être extraire en utilisant la méthode à double ligne. Sauf HMSIW, toutes les autres techniques de miniaturisation mentionnées ci-dessus pour la mise en œuvre de la plateforme multicouche. Parmi les techniques de fabrication diverses qui sont en mesure de fournir des substrats multicouches, le circuit imprimé multicouche est utilisé dans la conception des circuits rapportés dans cette thèse.---------- ABSTRACT Substrate integrated waveguide (SIW) is a guided-wave structure that enjoys the benefits of a high Q-factor and an excellent line-to-line isolation. SIW technique has been widely used in building passive components, such as couplers, dividers, filters, and phase shifters. Some active devices have also been developed with high Q-factor SIW resonators. Comparing to other types of planar transmission lines, the big form factor of SIW is a bottleneck for its integration with other conventional integrated circuits. Miniaturization techniques for SIW therefore become very urgent. The work in this dissertation starts with the review and discussion of existing miniaturization techniques for SIW, including ridge substrate integrated waveguide (RSIW), half-mode substrate integrated waveguide (HMSIW) and folded substrata integrated waveguide (FSIW). The impedance and propagation constant of the transmission lines based on these miniaturization techniques are calculated using transverse resonant method (TRM). Although these parameters can be extracted from full wave EM simulations, a fast computation be helpful in design optimization by using parametric analysis. One particular concern focuses on the relationship between attenuation constant and geometric parameters. Optimized dimensions of each miniaturized SIW are suggested based on the parametric analysis. The transmission line parameters of these miniaturized SIW transmission lines can be extracted using dual-line method. Except HMSIW, all other miniaturized techniques mentioned above need multilayer platform for implementation. Among various fabrication techniques which are able to provide multilayered substrate, multilayer printed circuit board is used in the design of the circuits reported in this dissertation. It is believed that the advantages of SIW circuit are important in millimeter wave applications, although the design might limit the operating frequency. Specifically, Rogers substrate R6002 is used in all our designs for proving the concepts investigated in this work. One principal step for using the SIW technology is to develop high-performance transitions and interconnects between substrate integrated circuits (SICs) and other types of transmission lines or circuits embedded in or surface mounted on the multilayer substrates. In this work, a novel transition between a microstrip line and an SIW in a multilayer substrate design environment is presented

Building blocks of a silicon photonic integrated wavelength division multiplexing transmitter for detector instrumentation = Bausteine für einen integrierten siliziumphotonischen Wellenlängenmultiplexsender zur Detektorinstrumentierung

In dieser Arbeit werden Datenübertragungssysteme für die Detektorinstrumentierung und die Herausforderungen dieser einzigartigen Anwendung untersucht. Begrenzt durch die hohe Strahlungsintensität, den verfügbaren Platz, niedrige Temperaturen usw., liegt die Auslesebandbreite von Detektoren nach dem derzeitigen Stand der Technik im Bereich von einigen zehn Gb/s pro Faser. Angesichts des ständig wachsenden Datenvolumens ist die Verbesserung der Übertragungsbandbreite ein dringend zu lösendes Problem. Daher wird in dieser Arbeit ein universell einsetzbares Konzept für einen integrierten, siliziumphotonischen Sender auf Basis der Wellenlängenmultiplex-Technologie vorgeschlagen. Die angestrebte Übertragungsbandbreite in der ersten Version beträgt 40 Gb/s. Zwei Schlüsselbausteine des integrierten Senders, der Mach-Zehnder-Modulator und der Wellenlängen-Demultiplexer, werden im Detail untersucht. Eine Reihe von Modulatoren mit unterschiedlichen Längen und Ätztiefen werden entworfen, hergestellt und charakterisiert. Für den Entwurf des Demultiplexers wird eine angepasste Entwurfsmethode entwickelt, die mit zwei dedizierten Brennpunkten arbeitet. Ein neuer Entwurfsparameter wird in diese Methode eingeführt, um sie flexibler und leichter anwendbar zu machen. Die Auswirkung der Modifizierung des eingeführten Parameters wird anhand einer Reihe vergleichbarer Bauelemente untersucht. Alle Charakterisierungen bestätigen die Machbarkeit des vorgeschlagenen Konzepts

LTCC-Based System-in-Package (SiP) Technology for Microwave System Integration

Monolithic low-temperature co-fired ceramic (LTCC) SiP modules have been presented for microwave applications. In order to integrate almost passive circuits of a radio system into the LTCC substrate, key technologies such as suppressing parasitic resonant modes, low-loss transitions and compact passive devices have been investigated. Well analyzed mechanisms on the parasitic resonant modes and their suppressing methods have been applied to high-isolation SiP structures. A strip line (SL) to CPW vertical transition using a stepped via structure embedding air cavities has been devised and has been used to design a SL BPF. A surface mount technology (SMT) pad transition has been developed by utilizing a modified coaxial line. A LPF composed of vertical plate capacitors and helical inductors and a 2 × 2 array antenna have been developed. A 61 GHz heterodyne transmitter LTCC SiP module has been implemented by monolithically embedding all passive circuits such as a SL BPF, 2 × 2 array antenna, SMT pads and feeding lines into it. A 60 GHz amplitude shift-keying (ASK) transceiver LTCC SiP module has been implemented as small as 17.8 × 17.9 × 0.6 mm3 by integrating a high-isolation via fence and a LPF. They have been characterized in terms of an output power, spectrum and link test

Phase-reversal travelling-wave optical modulators for broadband and bandpass applications

This thesis is concerned with the analysis, fabrication, and characterisation of phase-reversal optical modulators for both broadband and bandpass applications. The operation of modulation is described together with the parameters by which optical modulators are characterised. Direct and indirect modulation are discussed. Particular attention is given to optical modulators constructed using titanium-indiffused lithium niobate technology. For these devices, the most important characteristics determining the frequency response and efficiency are studied. The technique of phase-reversal is examined as a means of artificial phase-matching. Systematic procedures for the design of phase-reversal electrode patterns are proposed. A novel class of equalising modulator is presented. A simulation of a digital lightwave system based on an equalising phase-reversal device is constructed. Transmission lines on anisotropic substrates are examined. The limitations of a quasi-static analysis are highlighted. A full-wave treatment utilising the method of lines is presented for the study of electrooptic modulators. Full-wave analysis is employed to study conventional coplanar waveguide electrooptic modulators. A new modulator structure, based on a fin line, is presented for high frequency operation. A comprehensive analysis of this structure is undertaken, including a modal analysis of a dielectric discontinuity. Designs are developed toward the demonstration of a device operating above 30GHz. A novel phase-matching technique, particularly suited to the fin line configuration, is discussed. The major processes involved in the fabrication of titanium- indiffused lithium niobate devices are briefly described. The techniques by which high speed modulators are measured are discussed, including a novel method by optical down-conversion. Experimental measurements are presented for devices operating in the frequency range 0 to 40GHz. The thesis is concluded, with suggestions for future avenues of research

High-speed optical data transmission for detector instrumentation in particle physics

This work discusses the advantage of optical transmission utilizing wavelength-division multiplexing for the read-out of experimental data in detector instrumentation in high-energy physics, astroparticle physics or photon science. A multi-channel optical transmitter is developed as the core component on a silicon-on-insulator platform. It implements Mach-Zehnder modulators with a depletion-type pn-phase shifter in each arm, while the (de )multiplexers rely on planar concave gratings. The modulator design is expected to support a symbol rate in the range 40 GBd even with a phase shifter length of 3 mm. The development of an efficient simulation method is presented, which allows for the reliable prediction of the steady-state modulator characteristics. Furthermore, this work addresses the packaging technology for grating-coupled silicon photonic components. In particular, a fabrication and assembly process for a planar fiber-to-chip coupling using angle-polished single-mode fibers is developed. A long-term-stable coupling with a small footprint is achieved, of which the coupling efficiency is only weakly dependent on ambient conditions