Assessing the Circuit Requirements for a Real-Time Spectrum Analyzer on 65-nm CMOS Technology

This paper presents a detailed investigation into the development and assessment of a real-time spectrum analyzer implemented on a 65-nm CMOS Technology Application-Specific Integrated Circuit (ASIC). The analyzer features a developed Fast Fourier Transform (FFT) algorithm designed for optimal energy efficiency and minimal area usage, with a structured architecture for low, middle, and high-frequency ranges. Operating at a clock frequency of 14 MHz, the signal is sampled at 65536 Hz to produce a wideband power spectral density represented on a logarithmic scale. Integration with an ADS8881 ADC ensures high-fidelity input, and the output is transmitted to a host computer via a Serial Peripheral Interface (SPI). The study includes detailed evaluations through pre-synthesis simulation, post-synthesis simulation, and practical implementation on a Nexys4 FPGA board. The proposed FFT algorithm undergoes rigorous simulation at various synthesis stages, providing a nuanced performance analysis. Practical functionality is assessed on the FPGA, offering insights into the behavior of the circuit. The paper also discusses comprehensively the system’s power consumption and calculates the maximum area utilization for the 65-nm CMOS technology, providing essential metrics for optimizing power efficiency and physical footprint.