Novel microstrip backward coupler with metamaterial cells for fully planar fabrication techniques.

By using a recently proposed approach to synthesize 1D metamaterials in planar circuit technology, compatible with fully planar fabrication techniques, a novel backward coupler has been designed and fabricated. It has been implemented in microstrip technology by means of complementary split-ring resonators (CSRRs), etched in the ground plane, and series capacitive gaps. This way, we obtain the necessary left-handed properties for reversing the forward coupling (typical of co-directional coupled-line couplers) into backward coupling. The simulation as well as measurement results confirm the enhanced properties of the proposed couplers. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1205–1209, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21579 [ABSTRACT FROM AUTHOR]