This paper introduces an innovative Interpolation-based Radar Simulation System (IRSS) designed to simulate Doppler frequencies across multiple frequencies with minimal hardware complexity. Traditional radar simulation systems, such as Analog Radar System Simulators (ARSS) and Digital Radar System Simulators (DRSS), face challenges when supporting multi-frequency simulations due to the need for parallel processing of individual Doppler frequencies. The proposed IRSS exploits linear interpolation and superposition property, enabling a single interpolation process to handle multiple frequency components efficiently. The IRSS structure was implemented using an FPGA-based USRP, and its performance was evaluated through experim-ental testing. The results demonstrated that the IRSS accurately generated Doppler frequencies for both single and multi-frequency signals, maintaining consistency with theoretical predictions. The system effectively simulated Doppler shifts for various target speeds while preserving hardware simplicity, unlike traditional simulators that require increased resources proportional to the number of frequencies. This research highlights the advantages of using linear interpolation to reduce hardware complexity and improve scalability in radar simulators. Consequently, the proposed IRSS provides a cost-effective and efficient solution for modern radar systems that demand multi-frequency capabilities, making it well-suited for applications in complex environments such as autonomous vehicles, military operations, and aviation.

This paper presents the efficient digital Ex-core Neutron Flux Monitoring System (ENFMS) based on Field Programmable Gate Array (FPGA), designed to precisely measure reactor power levels across a wide operational range from 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−8</sup> % to 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> %. Conventional analog based ENFMS inherently suffers from low system performance, complex maintenance, susceptibility to environmental noise, and issues related to chip obsolescence. To address these challenges, the proposed system employs FPGA based digital signal processing, implementing three optimized measurement modes, namely Pulse, Mean Square Value (MSV), and Current, to effectively cover the entire operational range. A linear interpolation algorithm also provides smooth and continuous transitions between overlapping modes. Furthermore, the System on Chip (SoC) architecture integrates all signal processing functions onto a single FPGA chip, significantly reducing system size, complexity, and power consumption. Experimental evaluations performed on a Xilinx Kintex UltraScale FPGA platform demonstrated a short latency of approximately 3.49 μs at a 500 MHz clock frequency, high data throughput of 8.0 GB/s, and power consumption of about 6.3 W. Moreover, the system exhibited excellent measurement accuracy with a low RMS error of 0.0197 V throughout the entire operational range. Consequently, the proposed digital ENFMS significantly improves potential applicability, accuracy, and maintainability, making it well suited not only for existing nuclear instrumentation systems but also for emerging reactor technologies such as Small Modular Reactors (SMRs).