Design of 120GHZ FMCW Radar Liquid Level Measurement System

In mining, petroleum, food and other production fields, it is necessary to measure the liquid in the container and determine the height of the liquid level in the container. In this paper, a 120GHZ FMCW radar liquid level measurement scheme is proposed to solve the corrosivity problem in the process of liquid level measurement. In this paper, the working principle of FMCW radar is analyzed and sawtooth wave is selected as the modulation signal of radar input. The sawtooth modulation signal generation module, radar sensor module, filtering and amplifying module, ARM controller STM32 processing module and signal processing module are designed. The difference frequency signal processing algorithm of FMCW radar is introduced, and FFT algorithm and CZT algorithm are simulated and compared. Simulation results show that CZT algorithm can improve measurement accuracy.