Fig. 1. Schematic diagrams of asymmetric EIT-like structure with electrically switchable excitation port. (a) Overall structure diagram; (b) enlarged schematic of the part indicated by the blue dotted frame in Fig. 1 (a); (c) enlarged schematic of the part indicated by the red dotted frame in Fig. 1(a)

Fig. 2. Reflection coefficients and group delays of asymmetric EIT-like structures with electrically switchable excitation port in two cases. (a) Reflection spectra of case I; (b) reflection spectra of case II; (c) group delays of S11 in case I; (d) group delays of S22 in Case II

Fig. 3. Schematic and transmission characteristics of CRLH-TLs unit. (a) Schematic of the CRLH-TLs unit. (b) transmission phase of the CRLH-TLs under different capacitance values; (c) amplitude

Fig. 4. Magnetic field distribution of the structures. (a)-(d) The simulated magnetic field distribution at 3.97GHz in the bare cavity; (e)-(h) the simulated magnetic field distribution at 3.97GHz in the cavity with two SRRs

Fig. 5. Photos of the sample. (a) Overview of the overall structure; (b) partial enlarged photo with blue dotted line frame in Fig.5(a); (c) partial enlarged photo with red dotted line frame in Fig.5(a)

Fig. 6. Reflection spectra and group delay of the sample. (a) Measured S11 of the metamaterial varying along with V1 when V2 is fixed as 0V; (b) measured S22 of the metamaterial varying along with V2 when V1 is fixed as 0V; (c) measured S11 and S22 when V1=0V and V2=6V;(d) measured S11 and S22 when V1=6V and V2=0V; (e) group delay of S11 in Fig.6(c); (f) group delay of S22 in Fig.6(d)