A Single-channel Amplitude-comparison Wideband Direction Finding Method with Nonuniform Time Modulation

To avoid the limitation of the working bandwidth due to the phase ambiguity caused by the increase of carrier frequency in conventional time-modulated direction finding, a single-channel direction finding method with nonuniform time modulation is proposed in this paper. By modulating the signals received by different antenna elements at the same time with nonuniform periods, the amplitude information can be separately mapped to the corresponding modulated frequency without aliasing. With the amplitude ratio independently extracted from the harmonics, the single-channel direction finding for the incident signal can be achieved by utilizing the lookup table method. The proposed method can effectively improve the working bandwidth of time-modulated direction finding, and reduce the direction finding error caused by the change of target amplitude at different times. Numerical simulation results verify the feasibility of the proposed method. Meanwhile, the