Direction Finding Based on Time Modulated Array with Multiple Modulation Frequencies

A novel single channel direction finding method is proposed and verified, based on a two-element time modulated array (TMA). Periodic `ON-OFF' modulation is added to two elements, and the modulation frequency of one element is twice of that of the other one. After the power combiner, the incident direction is estimated by analyzing the phase relationship of generated harmonic components. The proposed method has a simple structure and concise signal processing. An experiment is provided to verify its effectiveness.