This paper addresses the critical need for miniaturized, high-efficiency power supply systems in advanced synthetic aperture radar (SAR) satellites, where increasing resolution demands require scalable and lightweight solutions. Focusing on MHz-level switching power supplies, this study evaluates key enabling technologies, including wide-bandgap devices, high-frequency magnetics, low-inductance capacitors, and resonant topologies. The results demonstrate that wide-bandgap devices achieve a 40% reduction in switching losses compared to silicon-based MOSFETs, benefiting from superior material properties and advanced packaging techniques. Optimized magnetic core selection and planar winding techniques contribute to a 30% reduction in copper losses at frequencies between 2 and 5 MHz, while specialized capacitors lower thermal dissipation by 17%. Furthermore, resonant converter topologies, supported by planar PCB layouts that minimize loop inductance, enable a power efficiency of 78.9% at 2 MHz. The proposed technical framework integrates these advancements to achieve an eightfold increase in power density for aerospace applications while ensuring radiation tolerance and reliability. Future research directions include active EMI cancellation, packaging optimization, and prognostics health management systems to enhance performance in extreme space environments.