volume | PIER Journals

Abstract

This paper introduces a 3 dB tunable symmetric left handed coupled line coupler implemented on ferrite substrate. The proposed coupler is realized in LH coplanar waveguide configuration constructed using interdigital capacitors and meandered line inductors. The analytical analysis and the numerical verification of the proposed couple line coupler are presented. The full wave numerical simulation results for different DC magnetic bias indicate that a tunable left handed coupled line coupler propagation with transmission coefficient up to 3 dB and isolation level more than 25 dB over a wide bandwidth can be achieved.

1. Smith, D. R., W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett., Vol. 84, No. 18, 4184-4187, 2000.
doi:10.1103/PhysRevLett.84.4184 Google Scholar

2. Falcone, F., T. Lopetegi, J. D. Baena, R. Marques, F. Martin, and M. Sorolla, "Effective negative-ε stopband microstrip lines based on complementary split ring resonators," IEEE Microwave and Wireless Components Lett., Vol. 14, No. 6, 280-282, 2004.
doi:10.1109/LMWC.2004.828029 Google Scholar

3. Elefteriades, G. V., A. K. Iyer, and P. C. Kremer, "Planar negative refractive index media using planar L-C loaded transmission line," IEEE Trans. Microwave Theory & Tech., Vol. 50, No. 12, 2702-2712, 2002.
doi:10.1109/TMTT.2002.805197 Google Scholar

4. Caloz, C. and T. Itoh, "Transmission line approach of left handed (LH) materials and microstrip implementation of an artificial LH transmission line," Proceedings of IEEE AP-S Int. Symp., 412-415, USA, June 2002. Google Scholar

5. Gao, J. and L. Zhu, "Guided-wave characteristics of CPW transmission line metamaterials, effective per-unit-length parameters," Proceedings of IEEE International Workshop on Antenna Technology: Small Antennas and Novel Metamaterials, 175-178, Singapore, March 7–9, 2005. Google Scholar

6. Lax, B. and K. Button, J. Microwave Ferrites and Ferrimagnetics, McGraw Hill, 1962.

7. Tsutsumi, M. and T. Ueda, "Nonreciprocal left-handed microstrip lines using ferrite substrate," Proceedings of IEEE MTT-S Int. Microwave Symposium, 249-252, USA, June 2004. Google Scholar

8. Abdalla, M. and Z. Hu, "On the study of CWP dual band left handed propagation with reciprocal and nonreciprocal characteristics over ferrite substrates," Proceedings of IEEE AP-S Int. Symp., 2578-2581, USA, June 2007. Google Scholar

9. Tsutsumi, M. and T. Ueda, "Left handed transmission characteristics of ferrite microstrip lines without series capacitive load," IEICE Trans. Electron., Vol. E89, No. 9, 1318-1323, 2006.
doi:10.1093/ietele/e89-c.9.1318 Google Scholar

10. Abdalla, M. and Z. Hu, "On the study of nonreciprocal left handed coplanar waveguide over ferrite substrate with only shunt inductive load," IEEE Microwave and Optical Technology Lett., Vol. 49, No. 11, 2810-2814, 2007.
doi:10.1002/mop.22848 Google Scholar

11. Nguyen, H. V. and C. Caloz, "Generalized coupled mode approach of metamaterial coupled line couplers: coupling theory, phenomenological explanation, and experimental demonstration," IEEE Trans. Microwave Theory & Tech., Vol. 55, No. 5, 1029-1039, May 2007.
doi:10.1109/TMTT.2007.895646 Google Scholar

12. Caloz, C., A. Sanada, and T. Itoh, "A broadband left handed (LH) coupled line backward coupler with arbitrary coupling level," Proceedings of IEEE MTT-S Int. Microwave Symposium, 317-320, USA, June 2003. Google Scholar

13. Islam, R. and G. Eleftheriades, "A planar metamaterial codirectional coupler that couples power backwards," Proceedings of IEEE MTT-S Int. Microwave Symposium, 321-324, Philadelphia, USA, June 8–13, 2003. Google Scholar

14. Shau, G. M. and M. S. Mu, "A novel 3-dB directional coupler with broad bandwidths and compact size using composite right/left handed coplanar waveguide," IEEE Microwave and Wireless Components Lett., Vol. 17, No. 5, 331-333, May 2007.
doi:10.1109/LMWC.2007.895694 Google Scholar

Prof. Mahmoud Abdelrahman Abdalla

Dr. Zhirun Hu