Implementation of Spectrum Analyzer using GOERTZEL Algorithm

Spectrum analysis is very essential requirement in instrumentation and communication signal interception. Spectrum analysis is normally carried out by online or offline FFT processing. The Goertzel algorithm is a digital signal processing (DSP) technique for identifying frequency components of a signal. While the general Fast Fourier transform (FFT) algorithm computes evenly across the bandwidth of the incoming signal, the Goertzel algorithm looks at specific, predetermined frequency. The FPGA being capable of offering high frequency data paths become suitable for realizing high speed spectrum analysis algorithms. The objective of this thesis is implementing Goertzel algorithm as high Q band pass filter on FPGA reconfigurable architecture. A digital frequency synthesizer produces frequency sweep which will drive the digital mixer. The digital mixer output is given to the Goertzel algorithm block. This algorithm output will be given to peak detection logic. The peak detector block output will be used for spectrum computation. The top level module integrates all these modules with appropriate clock and control circuitry. The results will be demonstrated by applying the deterministic signals such as sine wave and also with random band limited signals. It will be aimed to achieve 32 steps in the band of operation for spectrum computation on Spartan 3E low cost FPGA.