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Papers by Greg Warwar
This paper reports the first observation of fluorescence from the Cs(2+)F(-) state at 185 nm usin... more This paper reports the first observation of fluorescence from the Cs(2+)F(-) state at 185 nm using a laser-produced plasma as the excitation source. The dependence of the ionic excimer emission on CsF vapor pressure and temporally resolved emissions from Cs(2+)F(-) are reported. A method of pumping core-excited alkali atomic transitions using electron beam excitation is discussed.
Optics Letters, 1989
The first observation to the authors' knowledge of excimer molecules formed by reactive k... more The first observation to the authors' knowledge of excimer molecules formed by reactive kinetics in a laser-produced plasma is reported. Emission from XeF at 351 nm and a new ionic excimer (XeRb)(+) at 165 nm have been observed.
IEEE Journal of Solid-State Circuits, 1990
In this paper we report the extent to which dielectric relaxation in typical monolithic capacitor... more In this paper we report the extent to which dielectric relaxation in typical monolithic capacitors degrades the performance of chargemedistrihution analog-to-digital (A/D) converters, We show experimental device data from a monolithic capacitor test circuit, describe an empirical capacitor model fit to the rneasnrements, and compare simulated A/D system errors with those observed in a monolithic, 10-b, 3.3m&s A/D converter. The excellent agreement found in this comparison demonstrates that the transient error in A/D-converter code transition voltages due to dielectric relaxation may be accurately predicted. The modeling and simulation techniques discussed are important tools both for the selection of proper capacitor technology and iu the development of circuit designs insensitive to dielectric relaxation. This analysis is also applicable to any circnit where precision is derived from capacitor characteristics, such as sample-and-hold circuits aud switchedcapacitor filters.
IEEE Journal of Solid-State Circuits, 1993
Design techniques for self-calibration of the digitalto-analog converter DAC in a multibit sigma-... more Design techniques for self-calibration of the digitalto-analog converter DAC in a multibit sigma-delta modulator are described. When used in conjunction with dynamic element matching, self-calibration provides linearity performance suitable for digital audio applications. The dynamic element matching circuitry provides the mechanism of determining device mismatch for self-calibration. Practical circuit details and an effective calibration method are discussed. Test results from a 1-pm CMOS test chip are presented. In this test system, a second-order loop with a 3-b quantizer achieves an 89-dB dynamic range and-91-dB harmonic distortion after calibration. In addition, a new method of detecting the presence of tones is described, using the entropy of the spectrum of the decimation filter output.
Le Journal de Physique IV, 1994
Applied Physics Letters, 1989
This paper reports the first observation of fluorescence from the Cs(2+)F(-) state at 185 nm usin... more This paper reports the first observation of fluorescence from the Cs(2+)F(-) state at 185 nm using a laser-produced plasma as the excitation source. The dependence of the ionic excimer emission on CsF vapor pressure and temporally resolved emissions from Cs(2+)F(-) are reported. A method of pumping core-excited alkali atomic transitions using electron beam excitation is discussed.
Optics Letters, 1989
The first observation to the authors' knowledge of excimer molecules formed by reactive k... more The first observation to the authors' knowledge of excimer molecules formed by reactive kinetics in a laser-produced plasma is reported. Emission from XeF at 351 nm and a new ionic excimer (XeRb)(+) at 165 nm have been observed.
IEEE Journal of Solid-State Circuits, 1990
In this paper we report the extent to which dielectric relaxation in typical monolithic capacitor... more In this paper we report the extent to which dielectric relaxation in typical monolithic capacitors degrades the performance of chargemedistrihution analog-to-digital (A/D) converters, We show experimental device data from a monolithic capacitor test circuit, describe an empirical capacitor model fit to the rneasnrements, and compare simulated A/D system errors with those observed in a monolithic, 10-b, 3.3m&s A/D converter. The excellent agreement found in this comparison demonstrates that the transient error in A/D-converter code transition voltages due to dielectric relaxation may be accurately predicted. The modeling and simulation techniques discussed are important tools both for the selection of proper capacitor technology and iu the development of circuit designs insensitive to dielectric relaxation. This analysis is also applicable to any circnit where precision is derived from capacitor characteristics, such as sample-and-hold circuits aud switchedcapacitor filters.
IEEE Journal of Solid-State Circuits, 1993
Design techniques for self-calibration of the digitalto-analog converter DAC in a multibit sigma-... more Design techniques for self-calibration of the digitalto-analog converter DAC in a multibit sigma-delta modulator are described. When used in conjunction with dynamic element matching, self-calibration provides linearity performance suitable for digital audio applications. The dynamic element matching circuitry provides the mechanism of determining device mismatch for self-calibration. Practical circuit details and an effective calibration method are discussed. Test results from a 1-pm CMOS test chip are presented. In this test system, a second-order loop with a 3-b quantizer achieves an 89-dB dynamic range and-91-dB harmonic distortion after calibration. In addition, a new method of detecting the presence of tones is described, using the entropy of the spectrum of the decimation filter output.
Le Journal de Physique IV, 1994
Applied Physics Letters, 1989