Fully-Integrated Ultra-Wideband Radar System for Medical Imaging

  • Author / Creator
    Gao, Shengkai
  • Ultra-wideband (UWB) technology has attracted the attention of the industry and research community since the 3.1-10.6 GHz band spectral regulation was declassified for commercial use by the Federal Communications Commission (FCC) in 2002. UWB technology has positioned itself as a promising candidate for implementing short-range high-data-rate wireless communication systems, wireless sensor networks, and high-resolution radar/imaging systems because of the availability of large 7.5-GHz bandwidth, simple transceiver architecture, low power consumption, and robustness against narrowband interference. For the widespread adoption of UWB technology in wireless communication and radar systems, it is essential to develop fully-integrated cost-effective low-power UWB transceivers. Among all the fabrication methods, the complementary metal-oxide-semiconductor (CMOS) process stands out as a technology for implementing UWB circuits with low cost, low power consumption, and a high level of integration. As CMOS technology advances with higher transit frequency (fT ) but lower normal operation voltage, the maximum energy available from a single UWB pulse is further limited. Thus the design of long-range UWB transceiver systems becomes more and more challenging.
    The objective of this thesis is to implement a single-chip, meter-range UWB radar system in CMOS technology. Like a narrowband transceiver system, the transmission and detection range of the UWB system is positively related to the power (amplitude) of the transmitted signal. The first part of the research focuses on designing a UWB transmitter with high amplitude and low complexity. Implemented in 65-nm CMOS technology, two UWB transmitters capable of generating UWB pulses with a peak-to-peak amplitude (Vpp) more than two times the supply voltage are presented.
    Shifting the UWB signal synthesis to the digital domain using trapezoidal waves, the first design requires only a simple low-loss passive filter to conform to the UWB spectral regulations. The second design seeks to generate a higher output amplitude utilizing a wideband passive amplification technique. The second part of the research concentrates on the design and implementation of a correlation-based UWB radar receiver which is composed of a UWB single-ended-to-differential low-noise amplifier, a delay-locked loop with a minimum delay step of 20 ps and a period of 5.12 ns, a local replica generator that has the same structure as the first transmitter design, and a multiplier-based analog correlator. Reported simulation results verify the performance of the proposed UWB receiver and its building blocks.

  • Subjects / Keywords
  • Graduation date
    Spring 2021
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.