High Accuracy Distributed Kalman Filtering for Synchronizing Frequency and Phase in Distributed Phased Arrays

The coherent operation of a distributed phased array relies on accurate alignment of the electrical states (i.e., frequencies and phases) of the antenna nodes, which is challenging to achieve, particularly at microwave frequencies. To address this challenge, a high accuracy distributed Kalman filter (HA-DKF) is proposed wherein the neighboring nodes share their observations, the process noise covariance matrices, and the KF's predicted as well as updated state estimates and error covariance matrices, and perform consensus averaging on the shared information to precisely synchronize the nodes across the array. Simulation results are included to illustrate that our HA-DKF algorithm takes fewer iterations to yield better synchronization of the states compared to other filtering algorithms.