Theses and Dissertations

Date of Award

5-1-2026

Document Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Electrical Engineering

First Advisor

Heinrich Foltz

Second Advisor

Constantine Tarawneh

Third Advisor

Nantakan Wongkasem

Abstract

With the increasing length of freight trains, maintaining reliable wireless communication for onboard sensors has become increasingly challenging. Sub-GHz communication bands are a promising solution due to their long-range capability and suitability for rural railway environments. This study analyzes radio wave propagation around freight railcars to evaluate path loss and determine how antenna polarization affects wireless communication performance.

Time-domain full-wave electromagnetic simulations were performed using simplified railcar models and later validated through field testing using a vector signal generator, vector network analyzer (VNA), and spectrum analyzer. Various antenna polarization configurations were evaluated within the Sub-GHz Long Range (LoRa) frequency band under worst-case railcar placement conditions.

Testing was conducted between opposite ends of a railcar to obtain the median and standard deviation of path loss across the operating band. Results demonstrate that antenna polarization and environmental reflections significantly influence received signal strength. These findings provide practical guidance for optimizing transmit power, antenna placement, and frequency hopping strategies for onboard wireless sensing systems in railroad applications.

Comments

Copyright © 2026 Dario Hinojosa. All Rights Reserved. https://proquest.com/docview/3371128889

Download

Share

COinS