Invited paper: Dual-Keying Hybrid Modulation for Physical Layer Security in 5G/6G Scalable Array

This paper presents new analysis of Time Modulated Arrays (TMAs) used for physical layer security (PLS) in wireless networks, considering the electronics hardware limitation compared to conventional methods, leakage of the off elements in the switched antenna arrays. Such leakage degrades the harmonic power at the side-lobes, compromising security against eavesdropping. Addressing this challenge, the paper introduces an innovative design, Dual Keying Hybrid Modulation (DKHM), which combines a 1-bit direct modulator for Amplitude Shift Keying (ASK) modulation with time modulation. This approach significantly enhances security by improving the Bit Error Rate (BER) at side-lobes beyond 10 degrees with BER larger than $10^{-1}$. The findings suggest a paradigm shift in physical layer security strategies, taking into consideration the nonidealities of electronic and hardware components in communication systems. The proposed Dual Keying Hybrid Modulation, encompassing both amplitude and time modulation, demonstrates effectiveness in mitigating the power leakage issue and enhancing physical layer security.