Time interleaved counter analog to digital converters

The work explores extending time interleaving in A/D converters, by applying a high-level of parallelism to one of the slowest and simplest types of data-converters, the counter ADC. The motivation for the work is to realise high-performance re-configurable A/D converters for use in multi-standard and multi-PHY communication receivers with signal bandwidths in the 10s to 100s of MHz. The counter ADC requires only a comparator, a ramp signal, and a digital counter, where the comparator compares the sampled input against all possible quantisation levels sequentially. This work explores arranging counter ADCs in large time-interleaved arrays, building a Time Interleaved Counter (TIC) ADC. The key to realising a TIC ADC is distributed sampling and a global multi-phase ramp generator realised with a novel figure-of-8 rotating resistor ring. Furthermore Counter ADCs allow for re-configurability between effective sampling rate and resolution due to their sequential comparison of reference levels in conversion. A prototype TIC ADC of 128-channels was fabricated and measured in 0.13μm CMOS technology, where the same block can be configured to operate as a 7-bit 1GS/s, 8-bit 500MS/s, or 9-bit 250MS/s dataconverter. The ADC achieves a sub 400fJ/step FOM in all modes of configuration

Time interleaved counter analog to digital converters

The work explores extending time interleaving in A/D converters, by applying a high-level of parallelism to one of the slowest and simplest types of data-converters, the counter ADC. The motivation for the work is to realise high-performance re-configurable A/D converters for use in multi-standard and multi-PHY communication receivers with signal bandwidths in the 10s to 100s of MHz. The counter ADC requires only a comparator, a ramp signal, and a digital counter, where the comparator compares the sampled input against all possible quantisation levels sequentially. This work explores arranging counter ADCs in large time-interleaved arrays, building a Time Interleaved Counter (TIC) ADC. The key to realising a TIC ADC is distributed sampling and a global multi-phase ramp generator realised with a novel figure-of-8 rotating resistor ring. Furthermore Counter ADCs allow for re-configurability between effective sampling rate and resolution due to their sequential comparison of reference levels in conversion. A prototype TIC ADC of 128-channels was fabricated and measured in 0.13μm CMOS technology, where the same block can be configured to operate as a 7-bit 1GS/s, 8-bit 500MS/s, or 9-bit 250MS/s dataconverter. The ADC achieves a sub 400fJ/step FOM in all modes of configuration.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A Comparison between Laparoscopic and Open Pyeloplasty in Patients with Ureteropelvic Junction Obstruction

<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span style="font-family: Times New Roman;"><strong>Purpose:</strong> To compare clinical and radiological outcomes, complications, and hospital stay in laparoscopic and open pyeloplasty.</span></span></p><p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span style="font-family: Times New Roman;"><strong>Materials and Methods:</strong> From February 2002 to February 2003, 69 patients with ureteropelvic junction obstruction (UPJO) were assigned into two groups. Thirty-seven patients underwent transperitoneal laparoscopic pyeloplasty and 32 underwent open surgical pyeloplasty. Clinical symptoms were assessed before and after surgery, subjectively. Radiological assessment was also done three months postoperatively.</span></span></p><p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span style="font-family: Times New Roman;"><strong>Results:</strong> Mean operative time was 3.2 hours and 2.2 hours in laparoscopic and open pyeloplasty groups, respectively. Intraoperative bleeding was trivial in both groups and no complication or conversion to open surgery occurred. Postoperative complication rates were 24% and 6% in laparoscopic and open pyeloplasty groups, respectively. Mean hospital stay was similar (6.2 days) in the two groups. Mean follow-up was 16.5 months versus 11.4 months. Clinical and radiological success rates were 89% and 83.8% for laparoscopy group versus 96.5% and 87% for open pyeloplasty group. Due to recurrence of stricture, repeated surgery was performed in 4 patients of laparoscopy and 1 of open pyeloplasty groups.</span></span></p><strong><span style="font-size: 12pt; font-family: ">Conclusion:</span></strong><span style="font-size: 12pt; font-family: "> Laparoscopic pyeloplasty is a less invasive method with less pain, cosmetic advantages, no long incision, and outcome comparable with open surgery. Hospital stay is also not longer than that in open surgeries. Hence, laparoscopic pyeloplasty can be a substitute for skilled surgeons.</span&gt