Remote Characterization of Particle Streams With a Multistatic Dual Frequency Millimeter-Wave Radar

A multistatic dual frequency continuous-wave radar sensor with separated transmitters and receivers operating at 91.5 and 150.3 GHz is developed and used to monitor particle streams remotely through a dielectric wall. The streams consist of low concentrated multidisperse particles with sizes in the micrometer range. The physical relation between the particle stream's mass flow and the received signal power is derived and used for calibration. Also, scattering effects are investigated and used to develop a routine for the determination of particle dimensions. In a numerical study, it is shown how a double-bistatic antenna configuration can extend the limits of double-monostatic setups. Also, it is demonstrated how the antennas need to be adapted to the measurement environment to maximize the sensitivity of the radar sensor. Finally, measurement results of the mass loading, velocity, and radius of particles from a multidisperse stream are provided and discussed.