volume | PIER Journals

Abstract

In this paper, we propose a new way to compact the transmission lines, which has a general application to miniaturization of RF and microwave circuits. In this way, we use Nonuniform Transmission Lines (NTLs) instead of Uniform Transmission Lines (UTLs). To synthesize the desired Compact Length Transmission Lines (CLTLs), the characteristic impedance function of the NTLs is expanded in a truncated Fourier series. Then, the optimum values of the coefficients of the series are obtained through an optimization approach. The usefulness of the proposed structures is verified using some examples.

1. Dwari, S. and S. Sanyal, "Size reduction and harmonic suppression of microstrip branch-line coupler using defected ground structure," Microwave and Optical Technology Letters, Vol. 48, 1966-1969, 2006.
doi:10.1002/mop.21830

2. Falcone, F., T. Lopetegi, and M. Sorolla, "1-D and 2-D photonic bandgap microstrip structures," Microwave and Optical Technology Letters, Vol. 22, No. 6, 411-412, Sept. 1999.
doi:10.1002/(SICI)1098-2760(19990920)22:6<411::AID-MOP13>3.0.CO;2-U

3. Mandal, M. K., V. K. Velidi, A. Bhattacharya, and S. Sanyal, "Miniaturized quadrature hybrid coupler using high impedance lines," Microwave and Optical Technology Letters, Vol. 50, 1135-1137, May 2008.
doi:10.1002/mop.23320

4. Chen, W.-L. and G.-M. Wang, "Design of novel miniaturized fractal-shaped branch-line couplers," Microwave and Optical Technology Letters, Vol. 50, 1198-1201, May 2008.
doi:10.1002/mop.23316

5. Sakagami, I., M. Haga, and T. Munehiro, "Reduced branch-line coupler using eight two-step stubs," IEE Proc. Microw. Antennas Propag., Vol. 146, No. 6, 455-460, Dec. 1999.
doi:10.1049/ip-map:19990785

6. Lu, K., "An efficient method for analysis of arbitrary nonuniform transmission lines," IEEE Trans. Microw. Theory and Tech., 9-14, Jan. 1997.

7. Khalaj-Amirhosseini, M., "To analyze the nonuniform transmission lines by cascading short linear sections," Int. Conf. Inf. and Comm. Technologies: From Theory to Appl. (ICTTA 2008), 7-11, Damascus, Syria, Apr. 7-11, 2008.

8. Khalaj-Amirhosseini, M., "Analysis of coupled or single nonuniform transmission lines using step-by-step numerical integration," Progress In Electromagnetics Research, Vol. 58, 187-198, 2006.

9. Khalaj-Amirhosseini, M., "Analysis of nonuniform transmission lines using Taylor's series expansion," Int. J. RF and Microwave Computer-aided Engineering, Vol. 16, No. 5, 536-544, Sept. 2006.
doi:10.1002/mmce.20173

10. Khalaj-Amirhosseini, M., "Analysis of nonuniform transmission lines using fourier series expansion," Int. J. of RF and Microwave Computer-aided Engineering, Vol. 17, No. 3, 345-352, May 2007.
doi:10.1002/mmce.20229

11. Khalaj-Amirhosseini, M., "Analysis of nonuniform transmission lines using the equivalent sources," Progress In Electromagnetics Research, Vol. 71, 95-107, 2007.
doi:10.2528/PIER07020801

12. Khalaj-Amirhosseini, M., "Analysis of coupled or single nonuniform transmission lines using the method of Moments," Int. J. of RF and Microwave Computer-Aided Eng., Vol. 18, No. 4, 376-382, Jul. 2008.
doi:10.1002/mmce.20295

13. Khalaj-Amirhosseini, M., "Closed form solutions for nonuniform transmission lines," Progress In Electromagnetics Research B, Vol. 2, 243-258, 2008.
doi:10.2528/PIERB07111502

Dr. Mohammad Khalaj-Amirhosseini