Two-Dimensional Direction Finding Based on Time-Modulated Array with Double Long Baselines and Spectrum Harmonic Analysis

A novel two-dimensional direction-finding method is proposed based on time-modulated array (TMA) and spectrum harmonic analysis. Four antenna elements and double long baselines are meticulously arranged to form a TMA arm. Two TMA arms modulated by the radio frequency switches are placed vertically to form an L-shaped array. The azimuths and elevations of incident signals are first estimated independently using two TMA arms and then automatically paired through spectrum harmonic analysis. Thus, the two-dimensional direction of arrival can be accurately obtained. The proposed method has high precision and low complexity, and the utility is demonstrated through theoretical analysis and numerical simulations.