Design of tunable microwave transmission lines using metamaterial cells

In this paper, frequency tunable transmission lines are designed using metasurface split ring resonator unit cell. We prove that the tuning principle in metasurface transmission lines is based on the variation of the resonance frequency of the permeability. The frequency-tuning arises by changing the values of two gaps in the inner and outer rings of unit cell (g1 and g2). The branches of a disconnected gaps type conductor of each unit cell can be joined by switches (PIN diodes, MEMs, etc.). According to switch states ON or OFF, the unit cell has four different commutable behaviors which are 00, 01, 11, and 10. The results show that the resonance frequency of our metasurface transmission line is strongly shifted by about 2.5 GHz between the cases (01) and (11).