Design of a 16-element array antenna with a planar L-shaped probe for a direction of arrival estimation of the unidentified broadband signal

This article proposes the design of a 16-element array antenna with a planar L-shaped probe for a direction of arrival (DoA) estimation of an unidentified broadband signal. The individual element of the proposed antenna consists of a shorted radiating patch and the planar L-shaped probe for obtaining the broad matching characteristic, wide beamwidth, and miniaturization. The developed individual elements are adopted to implement a planar 4 x 4 array antenna and to verify beam scanning properties. To obtain the improved signal detection performance of the proposed array antenna, the optimal array spacing of the proposed antenna is determined by calculating a root mean square error (RMSE) and the side lobe level. The results demonstrate that the proposed 4 x 4 array antenna with the optimal array spacing is suitable for detecting the unidentified signals with low RMSEs in a given signal detection environment.