A Single-Channel Wide-Beam Radar Angle Estimation Accuracy Improvement Method by Nonlinear Wavefront Modulation

Target angle estimation with a single-channel wide beam antenna is a fundamental and crucial task in radar and remote sensing. Traditional target-angle estimation methods primarily rely on the phase differences of electromagnetic waves between array antennas, resulting in a high level of complexity in the antenna system. Furthermore, the angle estimation accuracy is also limited by the array antenna aperture. To alleviate the problems of system complexity and aperture limitations, a multi-media nonlinear wavefront modulation system (MN-WMS) for angle estimation is proposed. This system does not require modification of the original wide-beam antenna; therefore, the system complexity is low. By introducing nonlinear wavefront modulation information, the target angle can be accurately estimated. Specifically, we first propose a wavefront modulation angle estimation principle that introduces additional reference information for the angle estimation task. Then, we propose a multi-media modulator for electromagnetic waves modulation and present the implementation of the modulator. Finally, a multi-media nonlinear wavefront modulation angle estimation algorithm (MN-WMA) is proposed, which can be adaptively adjusted to balance processing time and accuracy require ments. High-accuracy angle estimation for a single-channel wide beam antenna can be effectively realized. Microwave anechoic chamber experiments show that the method achieves an angle-measurement accuracy of 0.163◦ with the single-channel wide beam antenna, verifying the effectiveness of the proposed method. This is a new exploration of using the nonlinear wavefront modulation method for angle estimation with a single-channel wide-beam antenna.