Browsing by Author "HASSAD, MOURAD"

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    Etude d’une antenne patch mirostrip à 2.4 GHz pour les applications WIFI et Bleutooth
    (2026) HASSAD, MOURAD
    Les bases théoriques des antennes microstrip (patch, substrat, plan de masse) et le fonctionnement en modes TM sont présentés, avec les formules de dimensionnement. Pour un FR-4 (εᵣ=4,4, h=1,6 mm) on obtient L=29,5 mm et W=38 mm. L'analyse paramétrique montre que L détermine principalement la fréquence (≈70 MHz/mm), l'épaisseur du substrat élargit la bande, et la position d'alimentation ajuste l'impédance. La modélisation sous MATLAB R2015a (Antenna Toolbox, MoM) a permis de simuler et de confronter simulations et prédictions analytiques : bon accord sur la fréquence, écarts sur la bande et l'impédance dus aux approximations. Un balayage paramétrique optimisé donne un design final : 2,40 GHz (S11 = -22 dB), bande 68 MHz, gain 6,2 dBi, rayonnement broadside. Le travail valide l'approche théorie–simulation et ouvre vers des designs multi-bande, miniaturisés ou en réseau..
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    STUDY AND SIMULATION OF FSK NARROWBAND DIGITAL MODULATION
    (2026) HASSAD, MOURAD
    This Master's end-of-study project provides a comprehensive theoretical, analytical, and practical study of Frequency Shift Keying (FSK) — a digital modulation technique that encodes binary data through discrete shifts in carrier frequency rather than amplitude or phase. The work spans modulation theory, in-depth FSK analysis, and hands-on simulation using MATLAB and Simulink. Modulation Background Chapter 1 surveys the landscape of modulation techniques, covering analog methods (AM, FM, PM) and the three principal digital schemes: Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), and Phase Shift Keying (PSK). FSK stands out for its constant-envelope waveform, making it inherently robust against amplitude noise, fading, and non-linear amplifier distortion — critical advantages over ASK-based systems that encode information in the more noise-susceptible amplitude domain. FSK: Technical Analysis Chapter 2 traces FSK from its origins in Reginald Fessenden’s two-tone Morse experiments (1910) through its modern variants. The chapter covers the complete FSK system architecture (binary source, carrier oscillators, modulator, transmission channel, demodulator, decision circuit), its mathematical formulation, and five key variants: Binary FSK (BFSK), Multiple FSK (MFSK), Continuous Phase FSK (CPFSK), Gaussian FSK (GFSK), and Minimum Shift Keying (MSK). Both coherent and non-coherent demodulation strategies are examined, with BER analysis showing coherent detection achieves Pb = ½ erfc(√(Eb/2N₀)) versus non-coherent Pb = ½ exp(−Eb/2N₀). FSK’s real-world applications include walkie-talkies, RFID systems, wireless sensor networks (IoT), satellite telemetry (TT&C), and telephone modems. Simulation: MATLAB & Simulink Chapter 3 implements FSK modulation and demodulation using two complementary approaches. The MATLAB script employs correlation-based coherent detection: the received signal is correlated against high- and low-frequency references for each bit interval, and the stronger correlation determines the decoded bit. The Simulink model builds a graphical block diagram using a Charge Pump Phase-Locked Loop (PLL) for non-coherent frequency tracking, mirroring real hardware receiver architectures. Both approaches were validated through scope visualisations showing binary NRZ source, carrier frequencies, modulated signal, and recovered data. Key Findings & Conclusions The project confirms that FSK’s constant-envelope property provides decisive advantages in noise-prone environments. Coherent detection yields superior BER performance, while non-coherent PLL-based detection is preferred in practical hardware for its simplicity and phase-jitter resilience. MATLAB scripting excels for academic signal analysis and BER studies, whereas Simulink is better suited to system-level prototyping and embedded code generation. Future directions include FPGA/SDR implementation, BER analysis under fading channels (Rayleigh/Rician models), and integration of FSK with emerging LPWAN and NOMA network frameworks.