2比特时间调制阵列的非理想特性建模研究

针对时间调制阵列存在的仿真与实际性能偏差问题，提出了一个考虑非理想特性的2比特时间调制阵列模型. 这一模型全面考虑了射频开关的瞬态切换、波束形成网络的幅相不平衡，以及天线的单元互耦、边缘效应、极化纯度等多种非理想特性，能够模拟实际的时间调制脉冲，进而准确分析2比特时间调制阵列的辐射性能. 一款Ku波段的2比特时间调制阵列样机验证了模型的有效性. 仿真和测试结果表明，相比理想模型，提出的非理想模型在计算副瓣电平、交叉极化电平、增益损失等方面都具有更高的准确性. 这一模型为分析实际2比特时间调制阵列的辐射性能提供了一种可靠的技术手段.

Modeling of nonideal characteristics in 2-bit time-modulated arrays

To minimize the performance discrepancy between practical time modulated arrays (TMA) and ideal models, we develop a nonideal mathematical model of 2-bit TMA in this work. The proposed nonideal model comprehensively considers a variety of nonideal characteristics of a practical 2-bit TMA, including transient switching effects of radio-frequency (RF) switches, amplitude-phase imbalances among RF channels, and mutual coupling, edge effects and polarization purity of antenna elements. With the proposed nonideal model, nonideal time modulation pulses are generated to accurately simulate the radiation performance of a practical 2-bit TMA. Numerical analysis and experimental validations for a Ku-band 2-bit TMA prototype are presented to demonstrate the effectiveness of the proposed nonideal model. As compared to ideal models, the proposed nonideal model exhibits higher accuracy in predicting sideband levels, cross-polarization levels, and gain losses. It provides a reliable way to analyze the radiation performance of practical 2-bit TMA.