Application of Composite Right/Left Handed (CRLH) Transmission Lines based on Complementary Split Ring Resonators (CSRRs) to the Design of Dual-Band Microwave Components

In this letter, composite right/left handed transmission lines based on complementary split ring resonators are applied to the design of dual-band microwave components. Specifically, impedance inverters operative at two (arbitrary) different frequencies (one of them within the left-handed band and the other within the right-handed band) are designed and applied to the implementation of a dual-band branch line hybrid coupler. The characterization of this device reveals good performance and dual-band operation. The fabricated device is small, fully planar, and vias are not required.