Phenomenon study of a microstrip line on a slot split ring resonator´s defected ground plane

There is a growing interest in small magnetic resonant structures. This interest has been spurred by the demonstration that specific subwavelength structures, that is, structures having electrically small dimensions compared to the wavelength, can exhibit an effective permeability which can be tuned to negative values over a finite frequency range (Pendry, J.B. et al., IEEE Trans. Microwave Theory and Techniques, vol.47, no.11, p.2075-84, 1999). Split ring resonators (SRRs) are subwavelength magnetic resonant structures built from nonmagnetic conducting sheets. They provide a negative permeability in the vicinity of the resonance frequency and their applications in filters using waveguides have been demonstrated (Burokur, S.N. et al., 27th ESA Antenna Tech. Workshop on Innovative Periodic Antennas, 2004). In order to have more compact devices, we need to work with printed circuit technology. What we call slot SRRs (SSRRs) are just slots having the shapes of SRRs and made in a conducting ground plane. The idea is to feed the SSRRs by a 50 Ω microstrip line. The microstrip line is milled on one face of a dielectric board and the SSRRs are milled in the ground plane on the other face of the board. The same phenomenon observed with electromagnetic band gap (EBG) structures is obtained, but with smaller dimensions ( λ/10).