학술논문

Nyquist Sampling and Degrees of Freedom of Electromagnetic Fields
Document Type
Periodical
Source
IEEE Transactions on Signal Processing IEEE Trans. Signal Process. Signal Processing, IEEE Transactions on. 70:3935-3947 2022
Subject
Signal Processing and Analysis
Communication, Networking and Broadcast Technologies
Computing and Processing
Electromagnetics
Fourier transforms
Bandwidth
Three-dimensional displays
Large scale integration
Interpolation
Frequency-domain analysis
Multidimensional sampling theorem
Nyquist sampling
degrees of freedom
field reconstruction
sensing
Helmholtz equation
Language
ISSN
1053-587X
1941-0476
Abstract
A signal space approach is presented to study the Nyquist sampling, number of degrees of freedom and reconstruction of an electromagnetic field under arbitrary scattering conditions. Conventional signal processing tools, such as the multidimensional sampling theorem and Fourier theory, are used to provide a linear system theoretic interpretation of electromagnetic wave propagation, thereby revealing the spatially bandlimited nature of electromagnetic fields. Their spatial bandwidth is dictated by the selectivity of the underlying scattering that allows establishing the Nyquist spatial sampling with a reduction of the number of fields' samples needed to be processed.