Novel Photonic Analog-to-Digital Converter Architecture for Precise Localization of Ultra-Wide Band Radio Transmitters

A novel photonic analog-to-digital converter (ADC) architecture tailored for the localization of transmitters employing ultra-wide band (UWB) radio technology is proposed and experimentally demonstrated in this paper. The proposed photonic-ADC architecture comprises several parallel branches each including an electro-optic sensor at different spatial locations capturing UWB signals simultaneously (sub-picosecond resolution). A single optical source is required in this architecture for all electro-optic sensors and also a single processing unit is needed to process the optically sampled data, thus simplifying the system implementation. A five-branch photonic-ADC has been developed for the experimental demonstration. The laboratory measurements demonstrate the successful detection and localization of fully-standard UWB transmitters as in WiMedia specification for very-low power radio signals (-65 dBm received power) captured. A mean three-dimensional positioning error of 48.5 cm with 15 cm standard deviation is achieved.