Theses and Dissertations from UMD

Permanent URI for this communityhttp://hdl.handle.net/1903/2

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

Browse

Filters

2005 - 20092

Settings

Author: search.filters.author.Yang, BoSubject: search.filters.subject.Engineering, Electronics and Electrical

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Ultra Small Antenna and Low Power Receiver for Smart Dust Wireless Sensor Networks
    (2009) Yang, Bo; Goldsman, Neil; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Wireless Sensor Networks have the potential for profound impact on our daily lives. Smart Dust Wireless Sensor Networks (SDWSNs) are emerging members of the Wireless Sensor Network family with strict requirements on communication node sizes (1 cubic centimeter) and power consumption (< 2mW during short on-states). In addition, the large number of communication nodes needed in SDWSN require highly integrated solutions. This dissertation develops new design techniques for low-volume antennas and low-power receivers for SDWSN applications. In addition, it devises an antenna and low noise amplifier co-design methodology to increase the level of design integration, reduce receiver noise, and reduce the development cycle. This dissertation first establishes stringent principles for designing SDWSN electrically small antennas (ESAs). Based on these principles, a new ESA, the F-Inverted Compact Antenna (FICA), is designed at 916MHz. This FICA has a significant advantage in that it uses a small-size ground plane. The volume of this FICA (including the ground plane) is only 7% of other state-of-the-art ESAs, while its efficiency (48.53%) and gain (-1.38dBi) are comparable to antennas of much larger dimensions. A physics-based circuit model is developed for this FICA to assist system level design at the earliest stage, including optimization of the antenna performance. An antenna and low noise amplifier (LNA) co-design method is proposed and proven to be valid to design low power LNAs with the very low noise figure of only 1.5dB. To reduce receiver power consumption, this dissertation proposes a novel LNA active device and an input/ouput passive matching network optimization method. With this method, a power efficient high voltage gain cascode LNA was designed in a 0.13um CMOS process with only low quality factor inductors. This LNA has a 3.6dB noise figure, voltage gain of 24dB, input third intercept point (IIP3) of 3dBm, and power consumption of 1.5mW at 1.0V supply voltage. Its figure of merit, using the typical definition, is twice that of the best in the literature. A full low power receiver is developed with a sensitivity of -58dBm, chip area of 1.1mm2, and power consumption of 2.85mW.
  • Thumbnail Image
    Item
    STUDY ON-CHIP METAL-INSULATOR-SEMICONDUCTOR-METAL INTERCONNECTS WITH THE ALTERNATING-DIRECTION-IMPLICIT FINITE-DIFFERENCE TIME-DOMAIN METHOD
    (2005-04-29) Yang, Bo; Goldsman, Neil; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The Alternating-Direction-Implicit Finite-Difference Time-Domain method is used to analyze the on-chip Metal-Insulator-Semiconductor-Metal interconnects by solving Maxwell's equations in time domain. This method is efficient in solving problems with fine geometries much smaller than the shortest wavelength of interest. The iteration algorithm is evaluated thoroughly with respects to stability, numerical dispersion, grid size, time-step size etc.. The dielectric quasi-TEM mode, the slow wave mode, and the skin-effect mode of the MISM structure are all analyzed. We find that semiconductors can readily operate from the slow wave mode, to the transition region, to the skin effect mode in state of art technology. This thesis shows that the silicon substrate losses and the metal line losses can be modeled with high resolution. Signal dispersion and attenuation over a wide range of doping densities and operating frequencies is discussed. Accurate prediction of interconnect losses is critical for high-frequency design with highly constrained timing requirements.