二次下变频实现宽带数字波束形成

宽带相控阵宽角扫描波束形成中，常用模拟延时线技术解决复包络偏移问题，但硬件的高代价阻碍其实际应用。本文在基于跟踪状态及发射线性调频信号的假设下，提出一种二次下变频方法实现宽带数字波束形成，本方法首先对阵元级接收数据进行模拟混频实现去斜，数字域再进行二次下变频，相位补偿后实现波束形成，最终通过傅氏变换获得散射点信息。

Realization of Wideband Digital Beam Forming by Twice Down-converting

In wide scanning angle beam forming of wideband phased array radar, analog delay line technology is commonly used to solve complex envelope shift problem, however, the high cost of hardware blocks its practical application. A twice down-converting method is presented to implement wideband digital beam forming under assumption based on tracking state and transmitting linear FM signal. This method is firstly to perform analog mixing for receiving data at array-element level to implement deramping, and twice frequency down-conversion further in digital domain, then implement beam forming after compensation in phase, and finally information at scattering point is ob- tained by Fourier transformation.