New and accurate synthesis formulas for asymmetric conductor‐backed coplanar waveguides

Abstract

New and accurate synthesis formulas for the asymmetric conductor‐backed coplanar waveguide (ACBCPW) are presented. They are obtained by using a differential evolution and particle swarm optimization algorithms. The synthesis formulas are useful to microwave engineers for accurately calculating the physical dimensions of ACBCPWs. The results of the synthesis formulas are compared with the quasi‐static analysis, a full‐wave electromagnetic simulator IE3D, and experimental results obtained in this work. The average percentage errors of the synthesis formulas found by using differential evolution and particle swarm optimization algorithms are calculated to be 0.56% and 0.93%, respectively, for 3024 ACBCPW samples having different electrical parameters and physical dimensions, compared with the results of respective quasi‐static analysis. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:211–216, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25666

ANN Synthesis Models Trained with Modified GA-LM Algorithm for ACPWs with Conductor Backing and Substrate Overlaying

“…10. It is observed that the results of the proposed ANN synthesis models for asymmetric CPWs with conductor backing are in agreement with the results of the synthesis formulas given in [13], and the accuracy of the proposed ANN synthesis models for symmetric CPWs with conductor backing is higher than that of the synthesis formulas presented in [29]. As clearly seen from Figs.…”

“…Synthesis model II Synthesis formula [13] Synthesis formula [29] comparisons among the results of the ANN synthesis models in the study, the synthesis formulas [13], [29], and the CMT analysis for symmetric and asymmetric CPWs with conductor backing (ε r1 =10.2, h 1 =1,270 µm, and g 2 /h 1 =1.5) are shown in Fig. 10.…”

“…In Table 4, the results obtained from the ANN synthesis models trained with the modified GA-LM algorithm are compared with the results of the CMT analysis, the synthesis formulas [13], [29], HFSS electromagnetic simulation [30], and experimental work [13]. The measured characteristic impedance with geometrical dimensions w, g 1 , and g 2 is represented by Z 0m , while the characteristic impedance values obtained from the HFSS and the CMT analysis using w, g 1 , and g 2 are represented by Z 0h , and Z 0c , respectively.…”

“…The measured characteristic impedance with geometrical dimensions w, g 1 , and g 2 is represented by Z 0m , while the characteristic impedance values obtained from the HFSS and the CMT analysis using w, g 1 , and g 2 are represented by Z 0h , and Z 0c , respectively. In Table 4, w I and w f represent the strip width obtained from the proposed ANN synthesis model I and the synthesis formulas [13], [29] using Z 0c , g 1 , and g 2 . Finally, the CMT analysis results (Z 0I and Z 0f ) are calculated using w I and w f for checking.…”

“…Owing to the increasing popularity of ACPWs for the design of microwave circuits, it becomes highly desirable to have accurate computeraided design (CAD) models for directly obtaining the physical dimensions of ACPWs. Based on the data obtained from the CTM analysis, the synthesis formulas for the ACPW and the ACPWCB had been developed with differential evolution (DE) and particle swarm optimization (PSO) algorithms [13], [14]. However, the synthesis formulas cannot be used for symmetric CPWs.…”