Engineering Optimization and Modeling Center, Reykjavik University, 102, Reykjavik, Iceland.
Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, 80-233, Gdansk, Poland.
Sci Rep. 2023 May 5;13(1):7305. doi: 10.1038/s41598-023-34414-2.
Re-design of microwave passive components for the assumed operating frequencies or substrate parameters is an important yet a tedious process. It requires simultaneous tuning of relevant circuit variables, often over broad ranges thereof, to ensure satisfactory performance of the system. If the operating conditions at the available design are distant from the intended ones, local optimization is typically insufficient, whereas global search entails excessive computational expenses. The problem is aggravated for miniaturized components, typically featuring large numbers of geometry parameters. Furthermore, owing to their tightly-arranged layouts, compact structures exhibit considerable cross-coupling effects. In order to reliably evaluate electrical characteristics under such conditions full-wave electromagnetic (EM) analysis is mandatory. Needless to say, EM-driven design over broad ranges of operating frequencies is an arduous and costly endeavor. In this paper, we introduce a novel procedure for rapid and reliable re-design of microwave passives. Our methodology involves concurrent scaling of geometry parameters interleaved with local (gradient-based) tuning. The scaling stage allows for low-cost relocation of the operating frequencies of the circuit, whereas the optimization stage ensures continuous (iteration-wise) alignment of the performance figures with their target values. The presented framework is validated using several miniaturized microstrip couplers, re-designed over extended ranges of the center frequencies. For all considered structures, satisfactory designs are successfully identified despite the initial designs being distant from the targets, whereas local tuning turns out to be demonstrably inferior. Apart from its efficacy, one of the most important advantages of the proposed framework is its simplicity, and the lack of problem-dependent control parameters.
重新设计微波无源器件以适应假设的工作频率或衬底参数是一项重要但繁琐的工作。它需要同时调整相关电路变量，通常是在很宽的范围内，以确保系统的满意性能。如果可用设计的工作条件与预期条件相差很大，局部优化通常是不够的，而全局搜索则需要大量的计算费用。对于小型化组件来说，这个问题更加严重，它们通常具有大量的几何参数。此外，由于其紧密排列的布局，紧凑结构表现出相当大的交叉耦合效应。为了在这种情况下可靠地评估电气特性，需要进行全波电磁（EM）分析。不用说，在广泛的工作频率范围内进行 EM 驱动设计是一项艰巨而昂贵的任务。在本文中，我们介绍了一种快速可靠的微波无源重新设计的新方法。我们的方法涉及几何参数的同时缩放，以及局部（基于梯度的）调整。缩放阶段允许以低成本重新定位电路的工作频率，而优化阶段则确保性能参数与目标值的连续（迭代）对齐。所提出的框架使用几个小型化微带耦合器进行了验证，这些耦合器在中心频率的扩展范围内进行了重新设计。对于所有考虑的结构，尽管初始设计与目标相差很大，但都成功地确定了满意的设计，而局部调整显然不如整体调整。除了其有效性之外，所提出的框架的最重要优点之一是其简单性，以及缺乏依赖于问题的控制参数。
