Renewable energy sources such as photovoltaic arrays and fuel cells play a crucial role in reducing dependence on fossil fuels and promoting environmental sustainability. Since these sources typically generate low-level DC voltage and have limited power capacity, voltage step-up is essential for their efficient integration into power grids or industrial systems. The inherently low output voltage poses significant challenges for direct load or grid connection, making high-efficiency DC-DC converters a vital component in power-conversion systems. Achieving high efficiency in DC-DC power converters has therefore become a critical criterion in practical applications.In this context, this paper introduces a dual-switch ultra-step- up converter derived from a quadratic boost structure. The proposed design integrates two cascaded boost stages, a coupled inductor, a voltage-multiplier circuit, and a switched capacitor, enabling a high voltage gain without the need for a transformer or a large turns ratio. Furthermore, the current-sharing approach through parallel diode paths significantly reduces diode losses and improves overall efficiency. Key features of the converter include reduced voltage stress on the switches, low input- current ripple, minimized diode and switch losses, simple control due to synchronous switch operation, and a common ground configuration.In addition, the proposed converter is compared with similar coupled-inductor-based converters reported in the past four years in terms of semiconductor stress, voltage gain, input-current ripple, and efficiency, demonstrating its superior performance. Finally, experimental validation on a 200-W prototype with a 24-V input and 400-V output confirms the high efficiency and outstanding performance of the proposed converter.