摘要
Due to the beam squint effect,phased array systems based on phase shifting cannot operate at wide bandwidths,making it difficult for them to meet the growing demands of communication systems.Photonic true-time-delay(TTD)architectures have become one of the mainstream solutions for broadband phased arrays due to their flat delay frequency response.However,most existing TTD-based architectures are specific beam-oriented configurations,making them inflexible when adapting to diverse users.In addition,when scaling to large arrays,using a large number of delay lines significantly increases the system's size,weight,and power(SWaP).Furthermore,in broadband beamforming systems,the sampling rate for back-end transceiver components increases to tens of gigahertz,while large volumes of data require processing.To address these challenges,we propose a microwave photonic channelized phased array(CHPA)receiver in which phase shifting is performed independently in multiple narrowband frequency channels,allowing simultaneous beamforming toward multiple frequency users.Instead of true time delays,the CHPA employs a form of virtual time delay to achieve phase control of all array elements(AEs)simultaneously,which requires significantly less delay range than conventional TTD systems and thus reduces SWaP.The narrowband parallel output also avoids massive digital processing for frequency-users'separation.We experimentally implement a 16-element receiver array with a 300 MHz channel bandwidth and demonstrate beam reception over 412 GHz within±60°.Full-space scanning per channel requires a maximum virtual delay of only 40 ps,whereas TTD-based schemes require 625 ps in each AE for the same coverage.
基金
National Natural Science Foundation of China(62135014)。
