A Submillimeter-Wave FMCW Pulse-Doppler Radar to Characterize the Dynamics of Particle Clouds

TL;DR

This paper introduces a 340-GHz FMCW pulse-Doppler radar capable of detecting and characterizing the dynamics of particle clouds at a 5-meter distance with high resolution, useful for industrial process monitoring.

Contribution

The work presents a novel 340-GHz FMCW radar system with high sensitivity and resolution for mapping particle clouds and single particles, demonstrating its effectiveness in industrial applications.

Findings

Able to detect particles from 0.1 to 10 mm in diameter

Achieves 1 cm range resolution and a few centimeters cross-range resolution

Successfully maps particle cloud dynamics at 5 meters distance

Abstract

This work presents a 340-GHz frequency-modulated continuous-wave (FMCW) pulse-Doppler radar. The radar system is based on a transceiver module with about one milli-Watt output power and more than 30-GHz bandwidth. The front-end optics consists of an off-axis parabola fed by a horn antenna from the transceiver unit, resulting in a collimated radar beam. The digital radar waveform generation allows for coherent and arbitrary FMCW pulse waveforms. The performance in terms of sensitivity and resolution (range/cross-range/velocity) is demonstrated, and the system's ability to detect and map single particles (0.1-10 mm diameter), as well as clouds of particles, at a 5-m distance, is presented. A range resolution of 1 cm and a cross-range resolution of a few centimeters (3-dB beam-width) allow for the characterization of the dynamics of particle clouds with a measurement voxel size of a few cubic centimeters. The monitoring of particle dynamics is of interest in several industrial applications, such as in the manufacturing of pharmaceuticals and the control/analysis of fluidized bed combustion reactors.