7 research outputs found

    High Performance LNAs and Mixers for Direct Conversion Receivers in BiCMOS and CMOS Technologies

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    The trend in cellular chipset design today is to incorporate support for a larger number of frequency bands for each new chipset generation. If the chipset also supports receiver diversity two low noise amplifiers (LNAs) are required for each frequency band. This is however associated with an increase of off-chip components, i.e. matching components for the LNA inputs, as well as complex routing of the RF input signals. If balanced LNAs are implemented the routing complexity is further increased. The first presented work in this thesis is a novel multiband low noise single ended LNA and mixer architecture. The mixer has a novel feedback loop suppressing both second order distortion as well as DC-offset. The performance, verified by Monte Carlo simulations, is sufficient for a WCDMA application. The second presented work is a single ended multiband LNA with programmable integrated matching. The LNA is connected to an on-chip tunable balun generating differential RF signals for a differential mixer. The combination of the narrow band input matching and narrow band balun of the presented LNA is beneficial for suppressing third harmonic downconversion of a WLAN interferer. The single ended architecture has great advantages regarding PCB routing of the RF input signals but is on the other hand more sensitive to common mode interferers, e.g. ground, supply and substrate noise. An analysis of direct conversion receiver requirements is presented together with an overview of different LNA and mixer architectures in both BiCMOS and CMOS technology

    Monolithic electronic-photonic integration in state-of-the-art CMOS processes

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 388-407).As silicon CMOS transistors have scaled, increasing the density and energy efficiency of computation on a single chip, the off-chip communication link to memory has emerged as the major bottleneck within modern processors. Photonic devices promise to break this bottleneck with superior bandwidth-density and energy-efficiency. Initial work by many research groups to adapt photonic device designs to a silicon-based material platform demonstrated suitable independent performance for such links. However, electronic-photonic integration attempts to date have been limited by the high cost and complexity associated with modifying CMOS platforms suitable for modern high-performance computing applications. In this work, we instead utilize existing state-of-the-art electronic CMOS processes to fabricate integrated photonics by: modifying designs to match the existing process; preparing a design-rule compliant layout within industry-standard CAD tools; and locally-removing the handle silicon substrate in the photonic region through post-processing. This effort has resulted in the fabrication of seven test chips from two major foundries in 28, 45, 65 and 90 nm CMOS processes. Of these efforts, a single die fabricated through a widely available 45nm SOI-CMOS mask-share foundry with integrated waveguides with 3.7 dB/cm propagation loss alongside unmodified electronics with less than 5 ps inverter stage delay serves as a proof-of-concept for this approach. Demonstrated photonic devices include high-extinction carrier-injection modulators, 8-channel wavelength division multiplexing filter banks and low-efficiency silicon germanium photodetectors. Simultaneous electronic-photonic functionality is verified by recording a 600 Mb/s eye diagram from a resonant modulator driven by integrated digital circuits. Initial work towards photonic device integration within the peripheral CMOS flow of a memory process that has resulted in polysilicon waveguide propagation losses of 6.4 dB/cm will also be presented.by Jason S. Orcutt.Ph.D

    Hardware and Methods for Scaling Up Quantum Information Experiments

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    Quantum computation promises to solve presently intractable problems, with hopes of yielding solutions to pressing issues to society. Despite this, current machines are limited to tens of qubits. The field is in a state of continuous scaling, with groups around the world working on all aspects of this problem. The work of this thesis aims to contribute to this effort. It is motivated by the goal of increasing both the speed and bandwidth of experiments conducted within our laboratory. Low-loss radio-frequency multiplexers were characterised at cryogenic temperatures, with some shown to operate at below 7mK. The Analog Devices ADG904 was one of these, and its insertion loss was measured at <0.5dB up to 2GHz. Their heat load was measured, and it was found that a switching speed of 10 MHz with an RF signal power of -30dB dissipates 43uW. Installing these switches yields a benefit over installing extra cabling in our cryostat for a switching speed of up to 2MHz and RF power of -30dBm. A switch matrix was prototyped for cryogenic operation, enabling re-routing of wiring inside a cryostat with a minimally increased thermal load. This could be used to significantly increase the scale of high frequency experiments. This switch has also been embedded within a calibration routine, facilitating measurement of a specific feature of interest at millikelvin temperatures. As the field of quantum engineering scales, such measurements will be crucial to close the loop, providing feedback to fabrication and semiconductor growth efforts. Finally, a rapid-turnaround test rig has been developed which has 32 high frequency and 100 DC lines, enabling tests of significant scale in liquid helium. This reduces the time per experiment at 4.2 K to hours rather than days, enabling tests such as thermal cycling, as well as the evaluation of on-chip structures or active electronics and classical computing hardware; which are all necessary elements of any solid state quantum computing architecture

    High-speed, low cost test platform using FPGA technology

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    The object of this research is to develop a low-cost, adaptable testing platform for multi-GHz digital applications, with concentration on the test requirement of advanced devices. Since most advanced ATEs are very expensive, this equipment is not always available for testing cost-sensitive devices. The approach is to use recently-introduced advanced FPGAs for the core logic of the testing platform, thereby allowing for a low-cost, low power-consumption, high-performance, and adaptable test system. Furthermore to customize the testing system for specific applications, we implemented multiple extension testing modules base on this platform. With these extension modules, new functions can be added easily and the test system can be upgraded with specific features required for other testing purposes. The applications of this platform can help those digital devices to be delivered into market with shorter time, lower cost and help the development of the whole industry.Ph.D

    How does the rise of China affect Malaysia's electronic and electrical sector?

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    After joining the WTO in 2001, China’s total exports grew by 19.3% per annum up to 2013 and the country emerged as the world’s biggest exporter of manufactured electronics. China’s rise has had an impact on developing countries such as Malaysia, a major exporter of electronic and electrical (E&E) goods. Malaysia aims to be a high-income economy by 2020, and upgrading its E&E value chain is critical to this goal. Malaysia is part of the East Asian production network and China imports intermediate inputs from Malaysia’s E&E for its final exports while simultaneously expanding in similar product spaces. This means the effect on Malaysia of China’s rise is complex. Contemporary literature divides the impact of China’s rise into competitive and complementary effects, and this research aims to further understand the effect of China’s rise on Malaysia’s E&E trade and investment channels, using a mixed methodology approach. The research analyses the bilateral E&E trade patterns, the extent of trade competition at the destination markets, with the trade structure disaggregated by sophistication and by type of goods1 analysis. Subsequently it examines China’s impact on the semiconductor machinery segment, a backward linkage of the IC industry. Finally, the influence of China’s rise on investments aspects of Malaysia’s E&E industry is also explored. 1 Types of goods category such as final goods, parts and accessories or durables. v The research finds that while imports from China compete with imports from Malaysia in the US and Japanese markets (the EU market is different), China’s competition in trade is also spurring Malaysia to upgrade its exports’ sophistication. China also creates new demand for Malaysia’s semiconductor machinery. Finally, while resulting in short-term job losses, China’s diversion of E&E investment from Malaysia provide opportunities for Malaysians to start new firms, and for MNCs based in Malaysia to upgrade their production
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