Applications of Right/Left Handed and Resonant Left Handed Transmission Lines for Microwave Circuit Design

Additional degrees of freedom in a design of miniature microwave devices can be provided by a combination of right-handed (RH) and left-handed (LH) transmission lines (TL), which differ in dispersion characteristics. We present some examples of such devices: planar resonator and filter with suppressed spurious response as well as a miniaturized matched balun and broadband digital phase shifters. Whereas these structures follow the right/left-handed TL approach, it is also possible to implement left-handed structures by following the resonant type approach, i.e. by using split rings resonators or complementary split rings resonators. Examples to illustrate the possibilities of this approach are also presented