No description available.

No description available.

A wireless sensor system is proposed for a targeted deployment in civil infrastructures (namely bridges) to help mitigate the growing problem of deterioration of civil infrastructures. The sensor motes are self-powered via a novel magnetic shape memory alloy (MSMA) energy harvesting material and a low-frequency, low-power rectifier multiplier (RM). Experimental characterizations of the MSMA device and the RM are presented. A study on practical implementation of a strain gauge sensor and its application in the proposed sensor system are undertaken and a low-power successive approximation register analog-to-digital converter (SAR ADC) is presented. The SAR ADC was fabricated and laboratory characterizations show the proposed low-voltage topology is a viable candidate for deployment in the proposed sensor system. Additionally, a wireless transmitter is proposed to transmit the SAR ADC output using on-off keying (OOK) modulation with an impulse radio ultra-wideband (IR-UWB) transmitter (TX). The RM and SAR ADC were fabricated in ON 0.5 micrometer CMOS process. An alternative transmitter architecture is also presented for use in the 3-10GHz UWB band. Unlike the IR-UWB TX described for the proposed wireless sensor system, the presented transmitter is designed to transfer large amounts of information with little concern for power consumption. This second method of data transmission divides the 3-10GHz spectrum into 528MHz sub-bands and "hops" between these sub-bands during data transmission. The data is sent over these multiple channels for short distances (?3-10m) at data rates over a few hundred million bits per second (Mbps). An UWB TX is presented for implementation in mode-I (3.1-4.6GHz) UWB which utilizes multi-band orthogonal frequency division multiplexing (MB-OFDM) to encode the information. The TX was designed and fabricated using UMC 0.13 micrometer CMOS technology. Measurement results and theoretical system level budgeting are presented for the proposed UWB TX.

Time-interleaved analog-to-digital converters are an attractive architecture for achieving a high speed, high resolution ADC in a power efficient manner. However, due to process and manufacturing variations, timing skews occur between the sampling clocks of the sub ADCs within the TI-ADC. These timing skews compromise the spurious free dynamic range of the converter. In addition, jitter on the sampling clocks, degrades the signal-to-noise ratio of the TI-ADC. Therefore, in order to maintain an acceptable spurious free dynamic range and signal to noise ratio, it is necessary to correct the timing skews while adding minimal jitter. Two analog-based architectures for correcting timing skews were investigated, with one being selected for implementation. The selected architecture and additional test circuitry were designed and fabricated in a 0.18??m CMOS process and tested using a 125 MSPS 16 bit ADC. The circuit achieves a correction precision on the order of 10???s of femtoseconds for timing skews as large as approximately 180 picoseconds, while adding less than 200 femtoseconds of rms jitter.

No description available.

We consider two different problems in quantization theory. During the first part we discuss the so called Bennett's White Noise Hypothesis, introduced to study quantization errors of different schemes. Under this hypothesis, one assumes that the reconstruction errors of different channels can be considered as uniform, independent and identically distributed random variables. We prove that in the case of uniform quantization errors for frame expansions, this hypothesis is in fact false. Nevertheless, we also prove that in the case of fine quantization, the errors of different channels are asymptotically uncorrelated, validating, at least partially, results on the computation of the mean square error of reconstructions that were obtained through the assumption of Bennett's hypothesis. On the second part, we will introduced a new scalar quantization scheme, called a Beta Alpha Encoder. We analyze its robustness with respect to the quantizer imperfections. This scheme also induces a challenging dynamical system. We give partial results dealing with the ergodicity of this system.

Thesis (M. Eng.)--Carleton University, 2001. / Includes bibliographical references (p. 129-132). Also available in electronic format on the Internet.

Thesis (M.Eng.) - Carleton University, 2002. / Includes bibliographical references (p. 83-86). Also available in electronic format on the Internet.

Thesis (M. App. Sc.)--Carleton University, 2003. / Includes bibliographical references (p. 94-96). Also available in electronic format on the Internet.

Thesis (M. App. Sc.)--Carleton University, 2005. / Includes bibliographical references (p. 179-183). Also available in electronic format on the Internet.