In this paper, two different neural models are proposed for calculating the quasi-static parameters of multilayer cylindrical coplanar waveguides and strip lines. These models were basically developed by training the artificial neural networks with the numerical results of quasi-static analysis. Neural models were trained with four different learning algorithms to obtain better performance and faster convergence with simpler structure. When the performances of neural models are compared with each other, the best test results are obtained from the multilayered perceptrons trained by the Levenberg- Marquardt algorithm. The results obtained from the neural models are in very good agreements with the theoretical results available in the literature.
2. Dib, N., T. Weller, M. Scardeletti, and M. Imparato, "Analysis of cylindrical transmission lines with finite difference time domain method," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, 509-512, 1999.
3. Su, H. C. and K. L. Wong, "Quasi-static solutions of cylindrical coplanar waveguides," Microwave Optical Technology Letters, Vol. 14, 347-351, 1997.
4. Dib, N. and A. Al-Zoubi, "Quasi-static analysis of asymmetric cylindrical coplanar waveguides with finite-extent ground," International Jour. Electronics, Vol. 87, 185-198, 2000.
5. Karpuz, C., M. Duyar, and A. Gorur, "Analysis of cylindrical conductor-backed coplanar waveguides," Microwave Optical Technology Letters, Vol. 27, 144-146, 2000.
6. Alkan, M., A. Gorur, and C. Karpuz, "Quasi-static analysis of cylindrical coplanar waveguide with multilayer dielectrics," International Jour. of RFand Microwave CAE, Vol. 8, 303-314, 1998.
7. Karpuz, C., A. Gorur, and M. Alkan, "Quasistatic analysis of cylindrical coplanar strip lines," Microwave and Optical Technology Letters, Vol. 17, 148-151, 1998.
8. Du, Z., K. Gong, J. S. Fu, Z. Feng, and B. Gao, "CAD models for asymmetrical, elliptical, cylindrical, and elliptical cone coplanar strip lines," IEEE Trans. Microwave Theory Tech., Vol. 48, 312-316, 2000.
9. Gorur, A., M. Duyar, and C. Karpuz, "Analytic formulas for calculating the quasistatic parameters of a multilayer cylindrical coplanar strip line," Microwave and Optical Technology Letters, Vol. 22, 432-436, 1999.
10. Akan, V. and E. Yazgan, "Quasi-static solutions of multilayer elliptical, cylindrical coplanar striplines and multilayer coplanar," IEEE Trans. Microwave Theory Tech., Vol. 53, 3681-3686, 2005.
11. Bedair, S. S. and I. Wolff, "Fast and accurate analytic formulas for calculating the parameters of a general broadside-coupled coplanar waveguide for (M)MIC applications," IEEE Trans. Microwave Theory Tech., Vol. 37, 843-850, 1989.
12. Haykin, S., Neural Networks: A Comprehensive Foundation, Macmillan College Publishing Comp., New York, USA, 1994.
13. Christodoulou, C. G. and M. Georgiopoulos, Application of Neural Networks in Electromagnetics, Artech House, MA, 2001.
14. Zhang, Q. J. and K. C. Gupta, Neural Networks for RF and Microwave Design, Artech House, 2000.
15. Watson, P. M. and K. C. Gupta, "Design and optimization of CPW circuits using EM-ANN models for CPW components," IEEE Transaction Microwave Theory Techniques, Vol. 45, 2515-2523, 1997.
16. Devabhaktuni, V. K., M. C. E. Yagoub, Y. Fang, J. Xu, and Q. J. Zhang, "Neural networks for microwave modeling: model development issues and nonlinear modeling techniques," International J. of RFand Microwave CAE, Vol. 11, 4-21, 2001.
17. Yildiz, C., S. Sagiroglu, and M. Turkmen, "Neural model for coplanar waveguide sandwiched between two dielectric substrates," IEE Proceedings --- Microwaves, Antennas and Propagation, Vol. 151, 7-12, 2004.
18. Guney, K., C. Yildiz, S. Kaya, and M. Turkmen, "Artificial neural networks for calculating the characteristic impedance of airsuspended trapezoidal and rectangular-shaped microshield lines," Journal of Electromagnetic Wave and Applications, Vol. 20, 1161-1174, 2006.
19. Jin, L. C., L. Ruan, and L. Y. Chun, "Design E-plane bandpass filter based on EM-ANN model," Journal of Electromagnetic Wave and Applications, Vol. 20, 1061-1069, 2006.
20. Mohamed, M. D. A., E. A. Soliman, and M. A. El-Gamal, "Optimization and characterization of electromagnetically coupled patch antennas using RBF neural networks," Journal of Electromagnetic Wave and Applications, Vol. 20, 1101-1114, 2006.
21. Yildiz, C., K. Guney, M. Turkmen, and S. Kaya, "Neural models for coplanar stripline synthesis," Progress in Electromagnetics Research, Vol. 69, 127-144, 2007.
22. Ganatsos, T., K. Siakavara, and J. N. Sahalos, "Neural network-based design of EBG surfaces for effective polarization diversity of wireless communications antenna systems," PIERS Online, Vol. 3, 1165-1169, 2007.
23. Siakavara, K., "Artificial neural network employment in the design of multilayered microstrip antenna with specified frequency operation," PIERS Online, Vol. 3, 1278-1282, 2007.
24. Kabir, H., Y. Wang, M. Yu, and Q. Zhang, "Applications of artificial neural network techniques in microwave filter modeling, optimization and design," PIERS Online, Vol. 3, 1131-1135, 2007.
25. Cengiz, Y., F. Gunes, and U. Kilic, "Optimization of a microwave amplifier using neural performance data sheets with a memetic algorithm," PIERS Proceedings, 227-231, 2007.
26. Hilberg, W., "From approximations to exact relations for characteristics impedances," IEEE Trans. Microwave Theory Tech., Vol. 17, 259-265, 1969.
27. Levenberg, K., "A method for the solution of certain nonlinear problems in least squares," Quart. Appl. Math., Vol. 2, 164-168, 1944.
28. Marquardt, D. W., "An algorithm for least-squares estimation of nonlinear parameters," J. Soc. Ind. Appl. Math., Vol. 11, 431-441, 1963.
29. MacKay, D. J. C., "Bayesian interpolation," Neural Computation, Vol. 4, 415-447, 1992.
30. Fletcher, R. and C. M. Reeves, "Function minimization by conjugate gradients," Comput. J., Vol. 7, 149-154, 1964.
31. Scales, E., Introduction to Non-linear Optimization, Springer-Verlag, New York, 1985.
32. Gill, P. E., W. Murray, and M. H. Wright, Practical Optimization, Academic Press, New York, 1981.