Tunable composite right/left-handed transmission line with positive/negative phase tunability using integrated MEMS switches

This paper reports a novel compact tunable composite right/left-handed transmission line (CRLH-TL) with multi-state phase tunability using integrated MEMS switches. It is possible to select multiple states with different positive/negative phase responses. The phase states can be determined by controlling the admittance of capacitors and impedance of inductors through MEMS switch operations. At 9.5 GHz, each state's phase is varied to be 26.7°, 14.6°, -6.7°, and -11.5°, where the first two states are in LH and the others in RH regions. At 9-15 GHz, insertion losses are measured to be less than 2.6 dB, and return losses were higher than 10 dB.