Threat detection with millimeter wave conformal antenna array using beamforming and direction of arrival estimation

In this article, an approach for the design of an electromagnetic nonimaging sensor is proposed for the application of threat detection. A millimeter wave (mmWave) conformal antenna array is designed which can act as a sensor node for detecting the threat. The techniques of beam switching and beamforming are employed on the designed array to achieve a directional beam and the optimum number of antenna elements essential for providing 360 degrees coverage after beam steering are computed. Simulations from beamforming achieve better results for less number of antennas compared to beam switching. Thereafter, direction of arrival (DOA) estimation analysis of the arriving signal is performed with the Cramer-Rao lower bound (CRLB) matrix considering the impact of channel fading along with elevation and azimuthal angles. Channel fading is taken into consideration recognizing its effect at mmWave frequency. These results are further validated with angle estimation from multiple signal classification (MUSIC) algorithm.