A direct digital synthesis chirped pulse Fourier transform microwave spectrometer
Abstract
Chirped pulse Fourier transform microwave (CP-FTMW) spectrometers have become the instrument of choice for acquiring rotational spectra, due to their high sensitivity, fast acquisition rate, and large bandwidth. Here we present the design and capabilities of a recently constructed CP-FTMW spectrometer using direct digital synthesis (DDS) as a new method for chirped pulse generation, through both a suite of extensive microwave characterizations and deep averaging of the 10-14 GHz spectrum of jet-cooled acetone. The use of DDS is more suited for in situ applications of CP-FTMW spectroscopy, as it reduces the size, weight, and power consumption of the chirp generation segment of the spectrometer all by more than an order of magnitude, while matching the performance of traditional designs. The performance of the instrument was further improved by the use of a high speed digitizer with dedicated signal averaging electronics, which facilitates a data acquisition rate of 2.1 kHz.
Additional Information
© 2013 AIP Publishing LLC. Received 4 June 2013; accepted 27 July 2013; published online 15 August 2013. The authors would like to acknowledge the National Science Foundation (Grant No. CHE-1214123 and the Graduate Research Fellowship Program) and National Aeronautics and Space Administration (Grant No. NNX09AM84G) for financial support, the Pate lab for helpful comments and the use of their AWG, Steve Shipman for CP-FTMW advice, Jeff Groseth for electrical support, Bob Dengler for DDS advice, an anonymous referee for a careful and observant review and bringing our attention to the early history of pulsed microwave spectroscopy, and the rest of the Blake lab, especially Brett McGuire, for their support.Attached Files
Published - RevSciInstrum_84_083104.pdf
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Additional details
- Eprint ID
- 41661
- Resolver ID
- CaltechAUTHORS:20131003-134419078
- CHE-1214123
- NSF
- NSF Graduate Research Fellowship
- NNX09AM84G
- NASA
- Created
-
2013-10-03Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences