Heterodyne spectrometers with very wide bandwidths

Andrew I. Harris

doi:10.1117/12.459150

17 February 2003 Heterodyne spectrometers with very wide bandwidths

Andrew I. Harris

Proceedings Volume 4855, Millimeter and Submillimeter Detectors for Astronomy; (2003) https://doi.org/10.1117/12.459150
Event: Astronomical Telescopes and Instrumentation, 2002, Waikoloa, Hawai'i, United States

Abstract

New astronomical and remote-sensing instruments require microwave spectrometers with modest spectral resolution over many gigahertz of instantaneous bandwidth. Applications include millimeter-wave searches for distant objects with poorly known redshifts, submillimeter and far-infrared observations of Doppler-broadened spectral lines from galaxies, and observations of pressure-broadened atmospheric lines. Wide bandwidths and the consequent stability requirements make it difficult to use general-purpose receiver and spectrometer architectures in these applications. We discuss analog auto- and cross-correlation lag spectrometers that are optimized for these observations. Analog correlators obtain their wide bandwidths by a combination of transmission line delays and direct voltage multiplication in transistor or diode mixers. We show results from a new custom transistor multiplier with bandwidth to 25 GHz. Stability becomes increasingly important as bandwidths broaden. We discuss system requirements for single-dish correlation radiometers, which have intrinsic high stability, and present results showing that analog cross-correlators are suitable backends for these receivers.

Citation Download Citation

Andrew I. Harris "Heterodyne spectrometers with very wide bandwidths", Proc. SPIE 4855, Millimeter and Submillimeter Detectors for Astronomy, (17 February 2003); https://doi.org/10.1117/12.459150

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available