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Your search keyword '"Kimber, David"' showing total 3 results
Start Over Author "Kimber, David" Publication Type Electronic Resources
3 results on '"Kimber, David"'

1. Class E amplifiers and their modulation behaviour

Author

Kimber, David Paul

Subjects
621.381535, TK Electrical engineering. Electronics Nuclear engineering
Abstract

The Class E power amplifier has very high drain efficiency under quasi-static conditions, and is a good candidate for Envelope Elimination and Restoration (EER) or other polar techniques. Unfortunately it has an unusual carrier frequency response, for which no analytic expression was known; this may have limited commercial use of the circuit. Two new steady state analyses are presented, which give the carrier frequency response in simple form, together with expressions for component values. Good agreement with measured data and existing numerical solutions is seen. Previous attempts at characterising the amplitude modulation (AM) behaviour of this circuit have assumed that it can be modelled as a first order low pass filter. It is shown that Class E AM can be modelled as an equivalent circuit, which behaves as a second order low pass filter. Measurements confirm the analysis.

Published
2006

2. Precise Stellar Radial Velocities of an M Dwarf with a Michelson Interferometer and a Medium-resolution Near-infrared Spectrograph

Author

Muirhead, Philip S., Edelstein, Jerry, Erskine, David J., Wright, Jason T., Muterspaugh, Matthew W., Covey, Kevin R., Wishnow, Edward H., Hamren, Katherine, Andelson, Phillip, Kimber, David, Mercer, Tony, Halverson, Samuel P., Vanderburg, Andrew, Mondo, Daniel, Czeszumska, Agnieszka, Lloyd, James P., Muirhead, Philip S., Edelstein, Jerry, Erskine, David J., Wright, Jason T., Muterspaugh, Matthew W., Covey, Kevin R., Wishnow, Edward H., Hamren, Katherine, Andelson, Phillip, Kimber, David, Mercer, Tony, Halverson, Samuel P., Vanderburg, Andrew, Mondo, Daniel, Czeszumska, Agnieszka, and Lloyd, James P.

Abstract

Precise near-infrared radial velocimetry enables efficient detection and transit verification of low-mass extrasolar planets orbiting M dwarf hosts, which are faint for visible-wavelength radial velocity surveys. The TripleSpec Exoplanet Discovery Instrument, or TEDI, is the combination of a variable-delay Michelson interferometer and a medium-resolution (R=2700) near-infrared spectrograph on the Palomar 200" Hale Telescope. We used TEDI to monitor GJ 699, a nearby mid-M dwarf, over 11 nights spread across 3 months. Analysis of 106 independent observations reveals a root-mean-square precision of less than 37 m/s for 5 minutes of integration time. This performance is within a factor of 2 of our expected photon-limited precision. We further decompose the residuals into a 33 m/s white noise component, and a 15 m/s systematic noise component, which we identify as likely due to contamination by telluric absorption lines. With further development this technique holds promise for broad implementation on medium-resolution near-infrared spectrographs to search for low-mass exoplanets orbiting M dwarfs, and to verify low-mass transit candidates., Comment: 55 pages and 13 figures in aastex format. Accepted by PASP

Published
2011
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