Synthesis of CRLH-TLs based on a shunt coupled-line section

The use of shunt coupled-line sections in order to synthesize artificial composite right/left handed transmission lines (CLRH-TL) is discussed. A unit cell consisting of a series broadband capacitor and a shunt coupled-line structure is proposed and analyzed by means of analytical equations. Two different configurations for the coupled lines are considered by placing short- or open-circuits at its ports. Several prototypes are manufactured and measured and a good agreement between analytical and measured results is obtained. Furthermore, the new unit cell presented here have advantages to bias active devices in CRLH TL-based distributed amplifiers (DAs).