480-Mbps, Bi-Directional, Ultra-Wideband Radio-Over-Fiber Transmission Using a 1308/1564-nm Reflective Electro-Absorption Transducer and Commercially Available VCSELs

Abstract

We describe 480 Mbps, bi-directional ultra-wideband (UWB) radio signal transmission over 1 km of single-mode optical fiber. Key components are a highly linear, reflective electro absorption transducer (EAT) and commercially available 1308-nm and 1564-nm VCSELs with 4.8-GHz bandwidth. Detailed EAT and 1308-nm VCSEL distortion analyses and measurements are presented highlighting the low intermodulation and harmonic distortion necessary for typical -18-dB wireless channel error vector magnitudes (EVMs). Direct VCSEL modulation with Wimedia supported band group 1 (3.1-4.8 GHz) MB-OFDM UWB signals was modelled with VPItransmissionMaker, suggesting a minimum EVM of -18.733 dB at 0.4502 OMI. This was confirmed by 480 Mbps upstream and downstream EVM measurements over fiber of -21.4 dB or better. Fully functional, half-duplex, bi-directional data transfer was achieved with interlocked RF switches.