This article delves into the development of Y-doped cobalt-copper ferrites (Co₀.₅Cu₀.₅YₓFe₂₋ₓO₄) and their enhanced magneto-dielectric properties for high-frequency applications. The study systematically investigates how varying concentrations of yttrium (x = 0.00, 0.03, 0.06, 0.09) influence the structural, magnetic, and dielectric characteristics of the ferrites. Key findings include lattice expansion, grain refinement, and improved crystallinity with Y³⁺ doping, alongside a significant reduction in dielectric loss and enhanced impedance matching. The optimal composition (x = 0.09) exhibits the highest magnetic permeability, a stable impedance matching ratio of ~0.68, and a broad effective bandwidth for microwave absorption, making it particularly suitable for miniaturized antennas and high-frequency devices. The research combines advanced characterization techniques such as XRD, SEM, UV–Vis spectroscopy, and impedance spectroscopy to provide a detailed understanding of the material's behavior. Additionally, the study explores the optical properties, revealing a widening bandgap with increasing Y content, which contributes to improved transparency and reduced defect states. The magneto-dielectric coupling is analyzed in depth, demonstrating how Y³⁺ doping optimizes the balance between magnetic permeability and dielectric permittivity, crucial for efficient signal propagation. Simulated reflection loss analysis further confirms the potential of the Y-doped ferrites for high-frequency electromagnetic applications. This work not only advances the understanding of rare-earth-doped ferrites but also provides practical insights for designing next-generation compact antenna systems with superior performance and stability.