频域宽带阵列波束形成技术优化设计

Optimal Design of Wideband Array Beamforming Technology in Frequency Domain

摘要:

为提高宽带相控阵系统的波束合成性能，该文针对宽带相控阵系统中的延时补偿问题，采用频域宽带阵列波束形成的方法，分析了宽带相控阵中应用交叠FFT进行时延补偿的原理和误差造成的原因；基于一个接收信号带宽为600MHz的64阵元的宽带相控阵系统，研究了子阵规模、FFT点数、交叠率、位宽、采样率等交叠FFT参数对延时精度、信号保真度和波束性能的影响，在满足工程应用的要求的同时对频域宽带阵列波束合成技术进行了优化；经研究确定子阵规模不超过9个天线阵元、FFT点数不小于512、交叠率不小于1/16、位宽不小于采用12bit时可以达到指标的要求，为交叠FFT方法应用在实际工程中提供了依据与参考，并使其工程实现复杂度降低。

Abstract:

In order to improve the beamforming performance of broadband phased array systems, this article focuses on the delay compensation problem in broadband phased array systems. The frequency domain broadband array beamforming method is used to analyze the principle of using overlapping FFT for delay compensation in broadband phased array systems and the reasons for errors. Based on a 64 element broadband phased array system with a received signal bandwidth of 600MHz, the effects of overlapping FFT parameters such as subarray size, FFT points, overlap rate, bit width, and sampling rate on delay accuracy, signal fidelity, and beam performance were studied. The frequency domain broadband array beam synthesis technology was optimized while meeting the requirements of engineering applications. After research, it has been determined that the size of the sub array should not exceed 9 antenna elements, the number of FFT points should not be less than 512, the overlap rate should not be less than 1/16, and the bit width should not be less than 12 bits. This provides a basis and reference for the application of the overlap FFT method in practical engineering, and reduces the complexity of its engineering implementation.