Reconfigurable Optical Beam Forming Network for Telecom Payloads

In space communication as well as space-to-ground communication an efficient beam forming network (BFN) feeding the phased arrayed antenna system in satellite telecom payloads plays a pivotal role. Owing to various advantages the microwave photonics based optical BFNs (OBFNs) are found to be more promising to meet the future demand over the traditional electronic BFNs. In this article, a novel OBFN is reported with cascaded coupled-resonator optical waveguides (CROWs) which can simultaneously control the signal bandwidth and group delay. Unlike traditional metallic heater low loss phase change material (PCM) is used to realize the reconfigurability ensuring compact structure and low power consumption. Thanks to localized tunning enabled by PCM and strategic structural implementation, for a fixed bandwidth of 5 GHz the delay can be continuously tuned over 100 ps whereas the bandwidth can be tunned from 4.3 GHz to 7 GHz for a fixed delay, showing a promise towards breaking the constraint present in delay-bandwidth product and find application in 5G-6G wireless communication.