This work presents a CMOS-compatible multilayer platform integrating energy storage and tunable varactor functionality within a compact system. By co-integrating antiferroelectric (AFE) and dielectric (DE) layers, the design achieves tunability up to 28%, an energy density of 52 J/cm3, and enhanced electrical breakdown strength of 5.8 MV/cm. The proposed architecture enables multifunctionality in a scalable on-chip approach, optimizing both energy efficiency and adaptive electronic applications. This experimental advancement offers a promising foundation for compact, high-performance AFE-based alternative to conventional single-purpose ferroelectric (FE) devices.