Improving Angle of Arrival Estimation Accuracy for mm-Wave Radars

Millimeter-wave radars are used to estimate the position of an object relative to the radar position in terms of the range, R, azimuth angle, θ, and elevation angle, ϕ. Typical radar operation includes transmitting a chirp signal, receiving the signal reflected by the objects in the environment, and mixing these signals at the receiver chain. For multiple antenna systems, the range can be calculated for each transmit and receive antenna, yielding multiple measurements. To increase the accuracy, these results are averaged. Angle estimation makes use of the phase differences between different antenna paths. Since there is only one calculation across all antenna elements, this calculation does not benefit from averaging. In addition to these random errors, systemic errors occur in the process of angle calculation. In this paper, we analyze the root cause of the systemic error and propose solutions to correct for this error to increase angle estimation accuracy.