16 research outputs found
Low jitter design techniques for monolithic CMOS phase-locked and delay-locked systems
Timing jitter is a major concern in almost every type of communication system. Yet the desire for high levels of integration works against minimization of this error, especially for systems employing a phase-locked loop (PLL) or delay-locked loop (DLL) for timing generation or timing recovery. There has been an increasing demand for fully-monolithic CMOS PLL and DLL designs with good jitter performance. In this thesis, the system level as well as the transistor level low jitter design techniques for integrated PLLs and DLLs have been explored.;On the system level, a rigorous jitter analysis method based on a z-domain model is developed, in which the jitter is treated as a random event. Combined with statistical methods, the rms value of the accumulated jitter can be expressed with a closed form solution that successfully ties the jitter performance with loop parameters. Based on this analysis, a cascaded PLL/DLL structure is proposed which combines the advantage of both loops. The resulting system is able to perform frequency synthesis with the jitter as low as that of a DLL.;As an efficient tool to predict the jitter performance of a PLL or DLL system, a new nonlinear behavioral simulator is developed based on a novel behavioral modeling of the VCO and delay-line. Compared with prior art, this simulator not only simplifies the computation but also enables the noise simulation. Both jitter performance during tracking and lock condition can be predicted. This is also the first reported top-level simulation tool for DLL noise simulation.;On the transistor level, three prototype chips for different applications were implemented and tested. The first two chips are the application of PLL in Gigabit fibre channel transceivers. High speed circuit blocks that have good noise immunity are the major design concern. Testing results show that both designs have met the specifications with low power dissipation. For the third chip, an adaptive on-chip dynamic skew calibration technique is proposed to realize a precise delay multi-phase clock generator, which is a topic that has not been addressed in previous work thus far. Experimental results strongly support the effectiveness of the calibration scheme. At the same time, this design achieves by far the best reported jitter performance
Topical Workshop on Electronics for Particle Physics
The purpose of the workshop was to present results and original concepts for electronics research and development relevant to particle physics experiments as well as accelerator and beam instrumentation at future facilities; to review the status of electronics for the LHC experiments; to identify and encourage common efforts for the development of electronics; and to promote information exchange and collaboration in the relevant engineering and physics communities
Single-Laser Multi-Terabit/s Systems
Optical communication systems carry the bulk of all data traffic worldwide. This book introduces multi-Terabit/s transmission systems and three key technologies for next generation networks. A software-defined multi-format transmitter, an optical comb source and an optical processing scheme for the fast Fourier transform for Tbit/s signals. Three world records demonstrate the potential: The first single laser 10 Tbit/s and 26 Tbit/s OFDM and the first 32.5 Tbit/s Nyquist WDM experiments
Single-Laser Multi-Terabit/s Systems
Optical communication systems carry the bulk of all data traffic worldwide. This book introduces multi-Terabit/s transmission systems and three key technologies for next generation networks. A software-defined multi-format transmitter, an optical comb source and an optical processing scheme for the fast Fourier transform for Tbit/s signals. Three world records demonstrate the potential: The first single laser 10 Tbit/s and 26 Tbit/s OFDM and the first 32.5 Tbit/s Nyquist WDM experiments
Pre-phase A: Development of a far-ultraviolet photometric- and spectroscopic-survey small-explorer experiment
We propose to perform a far ultraviolet photometric and spectroscopic survey covering the lambda lambda 1300-2000 band with a sensitivity comparable to that of the Palomar Sky Survey. This survey will proceed in three phases: an all-sky survey in three bands to 18-19.5(sup m), deep surveys of selected targets of interest in the same bands to 21-22(sup m), and a spectroscopic survey of 2 percent of the sky to 18(sup m) with a resolution of 3-20A. This mission, the Joint Ultraviolet Nightsky Observer (JUNO), can be performed by a Small-Explorer-class satellite
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Polymer waveguide based optical interconnects for high-speed on-board communications
This dissertation presents a study of multimode polymer waveguide technology for use in board-level communication links for future data centres and supercomputers. The motivation for this work comes from the severe interconnection bandwidth challenges faced by the conventional electrical interconnections technology and the potential performance advantages of optical interconnections. This thesis presents the work to address the bandwidth bottleneck by developing high-bandwidth multimode polymer waveguides. The use of multimode waveguides provides relaxed alignment tolerances enabling low-cost assembly tools. Siloxane polymer materials developed by Dow Corning Corporation are chosen to form the waveguides in this work due to their favourable optical properties (optical losses as low as 0.03 dB/cm and the ability to withstand temperatures in excess of 350 °C) that allow the waveguides to be directly integrated on printed circuits boards (PCBs) using conventional manufacturing processes. Useful design rules for the use of the multimode polymer waveguides are theoretically derived while the bandwidth-length products are investigated under various launch conditions. Frequency-domain measurements and ultra-short pulse measurements are then carried out to investigate the bandwidth performance of the polymer waveguides under different launch conditions and with lateral misalignments. The instrument-limited frequency-domain measurements show that these waveguides exhibit bandwidth-length products (BLPs) of at least 35 GHz×m, while the pulse broadening measurements reveal the actual BLPs to be in excess of 70 GHz×m under a 50 μm multimode-fibre (MMF) launch and 100 GHz×m for a restricted launch across a wide range of input offsets (>±10 μm). This shows the potential for data transmission rates of 100 Gb/s and beyond over a single waveguide channel. A theoretical model is developed using the measured refractive index profile and good agreement with the above experimental results is found. The effects of graded refractive index profiles on the performance of waveguide components (bends, crossings) are also investigated, demonstrating that appropriate refractive index engineering can provide enhanced waveguide loss performance while exhibiting adequate bandwidth. Waveguide bends with excess loss below 1 dB for a radius >6 mm, crossings with loss less than 0.02 dB/crossing while exhibiting adequate link bandwidth (>47 GHz×m) can be achieved for a MMF launch. On this basis, advanced modulation formats are investigated across the board-level waveguide links for further increasing the on-board data rates. Record NRZ-based 40 Gb/s and 56 Gb/s PAM-4 based data transmission over a 1 m long multimode polymer spiral waveguide are theoretically and experimentally demonstrated