FPGA-based spectrum analyzer with high area efficiency by Goertzel algorithm

FFT algorithm is the popular software design for spectrum analyzer, but doesn't work well for parallel hardware system due to complex calculation and huge memory requirement. Observing the key components of a spectrum analyzer are the intensities for respective frequencies, we propose a Goertzel algorithm to directly extract the intensity factors for respective frequency components in the input signal. Goenzel algorithm dispenses with the memory for z-1 and z-2 processing, and only needs two multipliers and three adders for real number calculation. In this paper, we present the spectrum extraction algorithm and implement a spectrum extractor with high speed and low area consumption in a FPGA (Field Programmable Gate Array) chip. It proves the feasibility of implementing a handheld concurrent multi-channel realtime spectrum analysis IP into a low gate counts and low power consumption CPLD (Complex Programmable Logic Device)chip.