# Analysis of Electromagnetic Interference Effects of 5G Signals on Radio Altimeters
## 1 Introduction
However, these studies primarily aimed to evaluate the interference resistance of RA receivers without conducting a comprehensive analysis of the interference process or theoretically validating the underlying mechanisms. [PERSON] et al. [15] used RA output height as an observation index for interference effects, analyzing the behavior of the receiver under different levels of interference. However, they did not address the mechanism of electromagnetic interference effects. [PERSON] et al. [16] studied the impact of 5G base station layout and antenna angles on RA interference and proposed a protected-area division plan. However, this plan has a limited protective effect on the RA system and may affect the coverage and efficiency of the 5G network. To effectively resolve interference issues, enhancing the RA receiver's anti-interference capability is essential, which requires a thorough analysis of the interference mechanisms to develop targeted protection strategies. Current research on 5G signal interference with RA receivers has largely relied on simulations and experiments, often overlooking detailed theoretical analysis and validation. This has led to a focus on qualitative interference assessments rather than in-depth explanations of RA receiver mechanisms or quantitative effect analyses. This limitation hinders the understanding of interference mechanisms and effects on RA receivers under 5G signal interference. Additionally, most research has concentrated on examining the impact of electromagnetic interference on the altitude output of RA receivers. This focus is insufficient, as 5G signal interference can induce various nonlinear effects in the receiver's RF front-end, significantly affecting both the output altitude and the overall functionality of the receiver. A comprehensive analysis of interference mechanisms in the RF front-end is essential for developing effective receiver protection designs. Our paper addresses these gaps by thoroughly investigating the mechanisms and behaviors of the RA receiver under 5G signal interference through mathematical modeling, simulation, and experimentation. Our study provides a comprehensive reference for understanding interference mechanisms in the 5G environment and guides the development of effective interference protection strategies. The rest of this article is organized as follows. Section 2 begins by analyzing the characteristics of 5G signals and establishing a mathematical model for their time-domain characteristics. Subsequently, the power-series method is employed to investigate the nonlinear effects of the RA receiver and to explore the interference mechanisms associated with 5G signals. Section 3 develops a behavioral-level simulation circuit model for the RA RF front-end. It then simulates and analyzes how the power and frequency parameters of the 5G signal affect the gain compression of RA intermediate frequency (IF) signals. Section 4 conducts an RA interference injection test to verify the gain compression effect of the IF signals and analyzes the impact of 5G interference signals on RA measurement performance. Finally, Section 5 presents the relevant conclusions.