Communication Experiment Dedicated Digital Spectrum Analyzer

In this paper, we propose a kind of practical system of spectrum analyzer that particularly designed for communication experiment. In this system the adopted main techniques include DDC (digital down conversion), CIC filter, FFT, DDS (direct digital synthesizer), and soft-core processor technique. We utilize the ADS2806 high speed A/D converter, FPGA, NIOS II soft-core processor and the TFT LCD. Compare to the similar products, the system has more advantages: (1) frequency resolution is variable and has 11 stalls; (2) by utilizing the FPGA and soft-core processor, the cost is decreased while the portability is increased (3) referencing the idea of software radio and SOPC, the analogue part is decreased a lot and this system basically achieves the digitalizing. Actual test results show that this spectrum analyzer can analyze the signal with the bandwidth in 0~5 MHz and the minimum resolution in 10 Hz.