Accelerated EM-Driven Microwave Optimization By Means Of Design Re-Utilization

This paper presents a technique for accelerating EM-driven optimization of microwave structures by design reutilization. A warm start for the optimization process is realized by combining information from pre-existing designs (e.g., available from previous design work on the same structure). This permits generation of a reasonable initial design, which reduces the computational cost of the optimization process. Additional speedup is achieved by extracting sensitivity data from the base designs and by using updating formulas. The proposed methodology has been demonstrated through a miniaturized microstrip rat-race coupler (RRC) optimized for operating frequencies and power split ratios within wide ranges of 0.5 GHz to 1.5 GHz and 0 dB to 4 dB, respectively. The computational cost of identifying the optimum designs is very low (around four EM analyses of the RRC on average). At the same time, accuracy of fulfilling design specifications is excellent (operating frequency and power split errors smaller than 10 MHz and 0.05 dB, respectively).