Ring resonator-based single-chip 1x8 optical beam forming network in LPCVD waveguide technology

Abstract

Optical ring resonators (ORRs) are good candidates to provide continuously tunable delay in beam forming networks (BFNs) for phased array antenna systems. Delay and splitting/combining elements can be integrated on a single optical chip to form an OBFN. A state-of-the-art 1×8 OBFN chip has been fabricated in LPCVD waveguide technology. It is designed with 1 input and 8 outputs, between which a binary-tree topology is used. A different number of ORRs (up to 7) are cascaded for each output. In this paper, the principle of operation is explained and demonstrated by presenting measurements on the 1×8 OBFN chip.