Fully planar implementation of generalized composite right/left handed transmission lines for quad-band applications

In this work, generalized composite right/left handed (CRLH) transmission lines are implemented in a fully planar configuration in coplanar waveguide (CPW) technology. These artificial lines exhibit two left handed (or backward) transmission bands and two right handed (or forward) transmission bands alternating, and are therefore of interest for the synthesis of quad-band microwave components. The lines are implemented by loading a host CPW with open split ring resonators (OSRRs) and open complementary split ring resonators (OCSRRs). Accurate circuit models of the different line elements, taking the parasitics into account, and the whole structure are experimentally validated. These lines are applied in this work to the design of a quad-band power divider operative at the GSM (900MHz and 1800MHz) and GPS (1176.45 MHz and 1575.42 MHz) frequency bands. The main innovative aspect of this contribution is the implementation of the reported quad-band structure in planar technology, without the presence of lumped components. This is also the first time that OSRRs and OCSRRs are combined for the synthesis of a quad-band structure.