Enhancing impedance control in microstrip lines using the Taguchi approach

Microstrip Transmission Lines (MTL) are crucial components in various electronic and communication systems because of their streamlined design, affordability, and wide frequency range. However, achieving precise control over their characteristic impedance (CI) is essential for optimal performance. This article utilises the Taguchi method (TM) to optimise the CI of MTL by systematically evaluating seven input control factors: strip width, strip thickness, dielectric height, ground plane thickness, frequency, dielectric conductivity, and conductor conductivity. Each factor is assessed at three different levels to find the best conditions for impedance regulation. Our findings reveal that strip width and dielectric height significantly influence the CI. Validation through analysis of variance (ANOVA) confirms the effectiveness of the TM. To demonstrate versatility across different application requirements, this work targets multiple CI of MTL values of (55 Ω and 70 Ω). As a practical application, MTL with a CI of 70 Ω were developed and analyzed through simulations in COMSOL Multiphysics, achieving a capacitance of 6.3829×10-11 F/m, resistance of 213.22 Ω/m, propagation constant of (1.5230+505.33i) m-1, shunt conductance of 2.5687×10-17 S/m, inductance of 3.1276×10-7 H/m, and CI of (70.000-0.21097i) Ω. This study provides a systematic approach for designing MTL customised for specific uses, removing the reliance on extensive trial-and-error approaches.