Transmission characteristics of millimeter and sub-terahertz channels through spatially ripple plasma sheath layers

TL;DR

This paper investigates how ripple structures in plasma sheaths affect millimeter and sub-terahertz wave transmission, providing insights crucial for improving communication with hypersonic vehicles in complex plasma environments.

Contribution

It introduces a combined modeling approach using ICP data and transfer matrix methods to analyze plasma inhomogeneities' effects on high-frequency signal propagation.

Findings

Ripple structures significantly influence channel performance.

Periodic ripples reduce cutoff frequency and cause frequency selectivity.

Random ripples lead to unpredictable transmission characteristics.

Abstract

The propagation of millimeter wave (MMW) and sub-terahertz (THz) signals through plasma sheaths is a critical concern for maintaining communication with hypersonic vehicles, yet the impact of complex plasma structures on these high-frequency channels remains insufficiently understood. In this work, we aim to characterize the transmission properties of MMW and sub-THz waves through plasma sheaths with various density profiles and ripple structures, addressing the gap in knowledge regarding the effects of plasma inhomogeneities on signal propagation. We employ an approach combining Inductively Coupled Plasma (ICP) data with transfer matrix methods (TMM) to model propagation through both flat and rippled plasma layers. Our findings reveal that ripple structures in plasma sheaths significantly affect channel performance, with periodic ripples reducing cutoff frequency and introducing frequency-selective behavior, while random ripples cause more unpredictable transmission characteristics. Our results explore the impact of the arrangement of plasma density layers and the parameters of ripple structures (period and amplitude) on channel transmission, group velocity dispersion, and angular dependence of wave propagation. These results provide crucial insights for the design and optimization of communication systems for hypersonic vehicles, potentially enabling the development of adaptive technologies capable of maintaining reliable communication in complex plasma environments.