Optical ring resonators (ORRs) are good candidates to provide continuously tunable delay in beam forming networks (BFNs) for phased array antenna systems. \ud
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.\ud
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.\ud
In this paper, the principle of operation is explained and demonstrated by presenting measurements on the 1×8 OBFN chip
