In this pioneering investigation, we meticulously synthesized Ba1−xSrxTiO3 nanoparticles, with Sr concentrations varying between 0.0 and 0.4 at intervals of 0.1, via a refined chemical approach. The crux of our study lies in establishing the intricate correlations between the chemical constitution (primarily Sr concentration), salient structural attributes (encompassing lattice and microstructural parameters), electrical dynamics and consequential microwave characteristics. X-ray diffraction (XRD) analyses reinforced the unity between the average ionic radii of the Ba/Sr ions and the lattice constants. Scanning electron spectroscopy (SEM) furnished insights into the microstructural intricacies, while the nominal chemical composition was ascertained via energy-dispersive X-ray (EDX) spectroscopy. A deep dive into the electrical realm revealed the temperature and field-dependent behaviors of permittivity, tangent losses and polarization. The electromagnetic traits of Ba1−xSrxTiO3 (where 0.0 < x < 0.4) were meticulously delineated by analyzing the experimentally determined S-parameters across a frequency spectrum of 6 to 18 GHz. Our findings elucidate that the predominant losses of electromagnetic wave energy are attributable to aggregated electrical losses, predominantly steered by polarization processes. Our findings demonstrate a significant attenuation in the reflected wave energy, with values spanning from − 14.3 to − 17.1 dB, highlighting the potential of these nanoparticles for cutting-edge applications in electromagnetic interference mitigation.