Available at: https://digitalcommons.calpoly.edu/theses/2999
Date of Award
6-2025
Degree Name
MS in Electrical Engineering
Department/Program
Electrical Engineering
College
College of Engineering
Advisor
Payam Nayeri
Advisor Department
Electrical Engineering
Advisor College
College of Engineering
Abstract
Distributed digital phased arrays are rising technologies that help enable applications such as search and rescue operations, wireless communication, radar navigation, and military operations, among many others. Due to their improved angular resolution, digital phased arrays offer superior direction-finding capabilities compared to traditional analog phased array systems. However, this improvement comes at the cost of increased complexity—specifically, the need for precise synchronization of phase, time, and frequency across physically separated nodes. Without synchronization, the distributed phased array's gain and direction-of-arrival (DoA) estimations deteriorate significantly.
There are multiple aspects to implementing and synchronizing a non-stationary distributed digital phased array. This research focuses on one aspect: it implements a decentralized synchronization algorithm that synchronizes the phase, frequency, and time of linear phased arrays to enhance direction-finding estimations, without reliance on external infrastructure such as GPS. For this research, the positions of the array elements are assumed to be known. A Two-Way Time Synchronization (TWTS) structure is simulated, which involves the transmission and reception of a two-tone waveform and calculating the time offsets between nodes to synchronize time. The two-tone waveform is capable of sending all the data needed for synchronization. Next, a phase-frequency consensus algorithm based on Kalman filtering is implemented to estimate and synchronize the phase and frequency states of each node in the array. By implementing this algorithm, we minimize the phase, frequency, and time offsets between nodes, consequently improving DoA estimations.
This work then validates the efficacy and ability of the synchronization algorithm to synchronize a linear array under various environmental and system challenges, demonstrating that the synchronized distributed digital array is capable of providing high-resolution DoA estimates. Furthermore, this research offers a straightforward and cost-effective synchronization solution for facilitating coherent operation in distributed digital phased arrays, with potential applications across a broad range of real-world systems.