Spatial-spectral imaging with microwave photonic arrays
Date
2022
Authors
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Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Unrelenting growth of wired and wireless communication systems has broken Moore's Law for electronics, leading the field to develop workarounds to handle even the contemporary demand for data, let alone the requirements of future networks. Modern communications systems rely upon complex computational algorithms to identify the physical locations of devices in order to maximize the power transmitted and received to each user for the best quality connection. Unfortunately, as wireless networks become saturated with users, these beamforming algorithms begin to break down in the face of high user density, resulting in degraded or in some cases nonexistent performance in crowded scenarios. ☐ To simultaneously address the problems of electronic throughput and the ballooning cost of high-performance computer chips, the field of microwave, or RF photonics offers great benefits to the processing, transmission, and reception of the RF fields carrying all data traveling around the world today. By mixing the RF fields upon optical carriers, fields of effectively infinite bandwidth may be processed independent of bandwidth, data rate, or the number of users through an optical Fourier transform coupled with high-speed photodetectors. ☐ In this work, the theory, design, construction and validation of systems for photonic processing of RF beams is presented. Firstly presented is a system that could offer up to a hundred-fold reduction in processing time for three-dimensional emitter localization with complexity potentially independent of the number of emitters in the scene. This system is later shown to be capable of coherent recovery through a heterodyne approach, concurrently recording the data signals present on all RF sources in a given environment. Additionally presented is the theory, design, and construction of a system capable of 2D beamforming with a linear Fourier transform, followed by experimental validation of 2D beamforming with a photonic integrated circuit. This represents a reduction in the footprint of the optical beamforming network by a factor of five to ten thousandfold. Harnessing the PIC platform has the potential to bring photonic beamforming to the masses, reducing cost, size, weight, and power (C-SWAP) requirements for photonic systems by at least this same order of magnitude, while retaining or enhancing all other capabilities.
Description
Keywords
Electromagnetics, Fourier Transforms, K-space, Photonics