A central component of a sideband separating (2SB) receiver is the quadrature hybrid which splits the incoming radio frequency signal into two branches with a 90°-phase shift. Its fabrication, however, is one of the factors limiting the operational bandwidth and the maximum frequency at which a 2SB can be built. In this paper a 100%-photonic approach to produce this split is presented. In this way, wider operational bandwidth and a higher maximum operational frequency could be achieved. We also present the first experimental results of a proof-of-concept implementation at 55 MHz that studied the phase stability and controllability of this approach using a commercial 90-degree optical hybrid.

Date Published: 23 July 2014
PDF: 7 pages
Proc. SPIE 9153, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII, 91532G (23 July 2014); doi: 10.1117/12.2055626

Published in SPIE Proceedings Vol. 9153:
Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII
Wayne S. Holland; Jonas Zmuidzinas, Editor(s)