As part of enabling software-defined microwave systems, Teledyne e2v is previewing a prototype optical link technology that could soon eliminate traditional copper data links in digital radio system designs. Highlighting the advantages of this move, Nicolas Chantier, Director of Strategic Marketing, said: "Our optical data link research signals that the radio front-end can finally be decoupled from the advanced back-end digital data processing of software-defined radio (SDR). Designers gain design flexibility, enhanced digital beamforming capabilities, and several other design freedoms."
Two copper serial interfaces dominate. They are the industry standard JESD204 link and an alternative license-free ESIstream from Teledyne e2v. The data interface in the sampling system must be carefully deployed. Especially in highly parallelized multi-channel (i.e. electronically steered beam) systems, the biggest challenge may be ensuring that the data samples are aligned accurately in time. Time alignment ensures signal phase information, thus preserving critical spatial information embedded in the received signal.
Synchronization across channels is further complicated by metastability, the pseudo-random behavior inherent in digital systems. It can be mitigated by careful design. Although optical data links power the modern global broadband backbone, to date there has been little attempt to replace traditional copper wires in radio front-end designs.
