Electro-optic correlator for large-format microwave interferometry: Up-conversion and correlation stages performance analysis

Abstract: In this paper, a microwave interferometer prototype with a near-infra-red optical correlator is proposed as a solution to get a large-format interferometer with hundreds of receivers for radio astronomy applications. A 10 Gbits/s Lithium Niobate modulator has been tested as part of an electro-optic correlator up-conversion stage that will be integrated in the interferometer prototype. Its internal circuitry consists of a single-drive modulator biased by a SubMiniature version A (SMA) connector allowing to up-convert microwave signals with bandwidths up to 12.5 GHz to the near infrared band. In order to characterize it, a 12 GHz tone and a bias voltage were applied to the SMA input using a polarization tee. Two different experimental techniques to stabilize the modulator operation point in its minimum optical carrier output power are described. The best achieved results showed a rather stable spectrum in amplitude and wavelength at the output of the modulator with an optical carrier level 23 dB lower than the signal of interest. On the other hand, preliminary measurements were made to analyze the correlation stage, using 4f and 6f optical configurations to characterize both the antenna/fiber array configuration and the corresponding point spread function.

 Fuente: Review of Scientific Instruments, 2017, 88(4), 044702

Editorial: American Institute of Physics

 Fecha de publicación: 10/04/2017

Nº de páginas: 8

Tipo de publicación: Artículo de Revista

DOI: 10.1063/1.4979811

ISSN: 0034-6748,1089-7623

Proyecto español: ESP2015-70646-C2-1-R ; CSD2010-00064.

Url de la publicación: https://doi.org/10.1063/1.4979811