Photonic Implementation of Remote Phased Array Receiver System

A photonic approach to implement a phased array receiver system for antenna remoting applications is presented and experimentally demonstrated. It has the abilities to perform frequency down conversion and to control the phase of the down converted IF signal, away from the remote antenna. This reduces the complexity of the remote antenna unit and is different to the reported photonics-based phase-tunable frequency converters. Fast 0° to 360° phase shift for the RF signal received by each antenna element in a phased array can be achieved by adjusting a single system parameter in the base station. The proposed photonics-based remote phased array receiver system with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> antenna elements can be constructed using commercial off-the-shelf components and offers robust performance regardless of environmental perturbations. Experimental results demonstrate a continuous 360° phase shift on the system output down converted IF signal for different input RF signal frequencies, via adjusting a DC voltage in the range of ±2.3 V into the system. Results also demonstrate the proposed structure does not suffer from the phase fluctuation problem when used in remote antenna applications.