The aim of this study is to examine the influence of the variation of the intrinsic impedance on the phase of a Gaussian pulse during propagation through a biological tissue. This paper describes a method for varying the intrinsic impedance while retaining the characteristics of the propagation medium. The propagation medium is considered as the superposition of four semi-infinite layers each characterized by their thickness, their conductivity, and their dielectric constant. These last parameters, on which the intrinsic impedance depends, are functions of the pulsation of the medium. In this work, we will test the continuity of the phase shift of the signal at the level of interfaces of biological layers with respect to that of the starting point as the function of the excitation pulsation. Next, we are going to vary the intrinsic. Next, we examine the influence of the variation of the intrinsic impedance at the interface on the phase shift of the signal at that level. We will adopt the Finite Difference Time Domain (FDTD) method to simulate the propagation of a Gaussian pulse. This method which is validated in previous work showed robustness to obtained signals very close to the reality at the interfaces. For these two tests, we will notice that the variation of intrinsic impedance has no influence on the variation of the phase at the interfaces.

This article presents a novel triangular-shaped pulse design for Ultra-Wide-Band (UWB) radio pulses, specifically in compliance with the IEEE 802.15.4a standard and the Spectral Masks of the Federal Communications Commission (FCC). Utilizing a Genetic Algorithm (GA), our objective is to develop a triple pulse form that satisfies the requirements set by these standards. Theoretical analysis and simulations showcase enhanced performance in comparison to existing UWB pulses, achieving a power loss mask of 3%, off-band emission of 5% within an 8% emission band, and a remarkable spectral efficiency exceeding 75%.