This letter introduces a novel, full-wave, physics-compliant stochastic dyadic Green's function (SDGF) framework for modeling electromagnetic (EM) multiple-input-multiple-output (MIMO) channels under wavenumber uncertainty. Unlike conventional phenomenological fading models, the proposed approach provides what appear to be the simplest exact random field models of electromagnetic line-of-sight (LoS) propagation that are also exact solutions of Maxwell's equations. Hence, we dub them Maxwellian random field theoretic models. These physically consistent stochastic models, including an analytically tractable wavenumber Gaussian model and a more general stochastic plane wave (SPW) model, serve as fundamental baseline models for stochastic LoS channel characterization. By preserving the vectorial structure of Maxwell's equations and the dispersion relation, the framework naturally incorporates both propagating and evanescent modes. Our analysis of ergodic capacity and degrees of freedom (DoF) reveals that the key results of the complex SPW model can be reproduced by the simpler Gaussian model with limited variance. Furthermore, we provide examples using 2D continuous MIMO systems, illustrating how the model's Maxwell-consistent stochasticity explains observed increases in channel capacity and DoF over the deterministic MIMO capacity baseline. These idealized Maxwellian random field theoretic models offer a physically grounded reference point for understanding fundamental limits in stochastic LoS propagation environments.

翻译：本文提出一种新颖的全波物理一致性随机并矢格林函数框架，用于波数不确定性下的电磁多输入多输出信道建模。与传统的唯象衰落模型不同，该方法提供了电磁视距传播中最简单的精确随机场模型，同时满足麦克斯韦方程组的精确解，故称之为麦克斯韦随机场理论模型。这些物理一致的随机模型（包括解析可处理的波数高斯模型和更通用的随机平面波模型）可作为随机视距信道表征的基础基准模型。通过保留麦克斯韦方程组的矢量结构和色散关系，该框架自然融合了传播模与倏逝模。遍历容量与自由度的分析表明，复杂随机平面波模型的核心结果可由方差受限的简单高斯模型复现。此外，我们以二维连续MIMO系统为例，揭示模型中的麦克斯韦一致性随机性如何解释信道容量和自由度相对于确定性MIMO容量基准的观测提升。这些理想化的麦克斯韦随机场理论模型为理解随机视距传播环境中的基本极限提供了物理基准参考点。