Direct constraint control for EM-based miniaturization of microwave passives

Area of Science:

• Electrical Engineering
• Electromagnetics
• Circuit Design

Background:

• Miniaturization of microwave circuits is critical for 5G, IoT, and wearable devices.
• Conventional designs face challenges with size reduction due to guided wavelength limitations.
• Complex miniaturized structures require computationally expensive electromagnetic (EM) simulations.

Purpose of the Study:

• To develop a more efficient constraint handling method for optimizing miniaturized microwave circuits.
• To address the computational cost associated with EM-driven parameter tuning and performance constraints.
• To improve the design process for compact microwave components while maintaining electrical performance.

Main Methods:

• Proposes an explicit constraint handling approach integrated with a trust-region gradient-search procedure.
• Determines search radius adjustments based on the reliability of linear constraint approximation models.
• Evaluates the method using three miniaturized coupler structures.

Main Results:

• Demonstrates the superiority of the proposed explicit method over the penalty function approach.
• Achieves efficient size reduction while satisfying electrical performance constraints.
• Confirms the method's effectiveness through comprehensive numerical experiments.

Conclusions:

• The explicit constraint handling method offers superior performance compared to penalty functions for miniaturized microwave circuit optimization.
• The approach is algorithmically simple and does not require circuit-specific tailoring.
• This method provides a more efficient and reliable solution for designing compact microwave components.