Design of portable field strength meter based on Nios II

In this paper, the functions of the field strength meter in the industrial field and the technical indexes of realizing the functions are studied. On this basis, a portable field strength meter based on the field programmable gate array (FPGA) embedded soft core processor (Nios II) is designed. The field strength meter takes Nios II soft core as the control center and realizes the field strength, frequency, carrier level and frequency of the industrial field signals measurement of spectrum, carrier noise ratio, etc. In this project, the input RF signal is processed with low noise, digital control attenuation, frequency conversion and envelope detection. The analog signal is transformed into digital signal by AD9226 chip. The data is cached by FIFO (first in first out) module in FPGA and handed to Nios II soft core for processing. The measurement type is selected by Verilog hardware programming language, and the result is displayed by LCD directly.