Optimal harmonic beam steering of the time-modulated linear antenna array (TMLAA) with optimized and pre-defined ON and OFF switching schemes are proposed in this work. Three different approaches are considered to obtain various beam steering behaviors of TMLAA. The first approach is considered for the optimization of ON–OFF switching sequence for the steering of the harmonic beams toward approximately ±30° along with the simultaneous reduction of side lobe level (SLL) and side band level (SBL). Second approach is considered for the optimization of ON–OFF switching sequence for the steering of the harmonic beams toward approximately ±30° and ±60° simultaneously. Third approach is considered for the optimal reduction of SLL and SBL of harmonically steered beams for a pre-defined ON–OFF switching scheme. Two unique cost function is proposed in this work to achieve the optimal parameter for above mentioned three different approaches. The first cost function is used for the optimization of T_on and T_off switching sequence and antenna element spacing of the array. These optimal values will lead to steer the main beam of first positive and negative harmonic radiation from the main beam of the fundamental radiation pattern and reduce SLL and SBL simultaneously. Second cost function deals with the optimization of excitation amplitude and distance between any two consecutive antennas of the array. These optimal values lead to reducing the SLL and SBL simultaneously harmonically steered beam obtained by pre-defined T_on and T_off switching sequence. Optimization algorithm applied to get the optimal value of the variable parameters is Novel Particle Swarm Optimization. Further to explain the stated proposed approach, four different sets of 10-, 16-, 20-, 32-element TMLAA are taken as an example. Some of the simulation results are validated through electromagnetic simulator to validate the result obtained by MATLAB.

中文翻译：

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具有优化和预定义 RF 切换的定时天线阵列中的多波束导向谐波模式合成

在这项工作中提出了具有优化和预定义开和关切换方案的时间调制线性天线阵列 (TMLAA) 的最佳谐波波束控制。考虑了三种不同的方法来获得TMLAA 的各种波束控制行为. 第一种方法被考虑用于优化 ON-OFF 开关序列，以便将谐波光束转向大约 ±30°，同时降低旁瓣电平 (SLL) 和边带电平 (SBL)。第二种方法被考虑用于优化 ON-OFF 开关序列，以便同时将谐波光束转向大约 ±30° 和 ±60°。对于预定义的 ON-OFF 切换方案，考虑了第三种方法来优化降低谐波控制光束的 SLL 和 SBL。在这项工作中提出了两个独特的成本函数来实现上述三种不同方法的最佳参数。第一个代价函数用于优化T _on和T _off阵列的开关顺序和天线单元间距。这些最佳值将导致从基本辐射方向图的主光束转向第一正和负谐波辐射的主光束，并同时降低 SLL 和 SBL。第二个成本函数处理阵列的任意两个连续天线之间的激励幅度和距离的优化。这些最佳值导致同时减少由预定义的T _on和T _off获得的 SLL 和 SBL 谐波转向光束切换顺序。用于获得可变参数最优值的优化算法是新型粒子群优化算法。为了进一步解释所提出的方法，我们以四组不同的 10、16、20、32 元素 TMLAA 为例。部分仿真结果通过电磁仿真器进行验证，以验证MATLAB得到的结果。