Linear electo-optic effect applied to a radio astronomy
correlator
N. Ross Price,
Philipp P. Kronberg, Keigo Iizuka, and Alois P. Freundorfer
Abstract-Studies of weak millimetre-wave cosmic radio sources in
the next generation of millimetre interferometers will, for optimal
sensitivity to continuum radio sources, require continuum cross
correlators with an input passband of approximately 10 GHz, in
comparison to the 500 MHz devices presently installed. We have
designed and tested an optoelectronic continuum correlator which can
achieve such high bandwidths using integrated optic Mach-Zehnder
interferometric modulators (to convert the IF signals from the radio
telescope receivers to optical signals) and photoreceivers (to
convert the optical signals back to electrical signals). A prototype
real-channel continuum correlator of this type is described. It
performs with an overall efficiency of 81 +/- 3%, which compares
favorably with typical electronic digital and analogue correlators
currently used in radio astronomy.
Funding: NSERC and OLLRC
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