A communication device (600; 700A; 700B, 700C; 700D) for propagating an electromagnetic wave around a blocking structure (650; 750), the communication device comprising: a passive coupling device (610; 710A; 710B; 710C; 710D) configured to be disposed proximate to a first side of the blocking structure (650; 750) and configured to capture the electromagnetic wave, a transmitter configured to be disposed proximate to a second side of the blocking structure (650; 750), and a waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) electromagnetically coupled to the passive coupling device (610; 710A; 710B; 710C; 710D) and the transmitter and configured to be disposed around the blocking structure (650; 750), the waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) having a resonance frequency matched with the passive coupling device (610; 710A; 710B; 710C; 710D), the waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) configured to propagate the electromagnetic wave captured by the passive coupling device (610; 710A; 710B; 710C; 710D), wherein the transmitter is configured to reradiate the electromagnetic wave, wherein the waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) is flexible and comprises a base material (115; 215A; 215D) made of silicone composite and a plurality of resonators (120; 220A; 310A; 310B; 310C; 310D; 310E; 310F; 310G) made of a ceramic material and having a spherical shape, wherein at least two of the plurality of resonators (120; 220A; 310A; 310B; 310C; 310D; 310E; 310F; 310G) are spaced according to a lattice constant (α) that defines a distance between a center of a first one of the resonators (120; 220A; 310A; 310B; 310C; 310D; 310E; 310F; 310G) and a center of a neighboring second one of the resonators, and wherein a ratio of a diameter (D) of the resonators to the lattice constant (α) is less than one. a passive coupling device (610; 710A; 710B; 710C; 710D) configured to be disposed proximate to a first side of the blocking structure (650; 750) and configured to capture the electromagnetic wave, a transmitter configured to be disposed proximate to a second side of the blocking structure (650; 750), and a waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) electromagnetically coupled to the passive coupling device (610; 710A; 710B; 710C; 710D) and the transmitter and configured to be disposed around the blocking structure (650; 750), the waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) having a resonance frequency matched with the passive coupling device (610; 710A; 710B; 710C; 710D), the waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) configured to propagate the electromagnetic wave captured by the passive coupling device (610; 710A; 710B; 710C; 710D), wherein the transmitter is configured to reradiate the electromagnetic wave, wherein the waveguide (110; 210A; 210D; 300A; 300B; 300C; 300D; 300F; 300G; 510A; 510B; 510C; 630; 730) is flexible and comprises a base material (115; 215A; 215D) made of silicone composite and a plurality of resonators (120; 220A; 310A; 310B; 310C; 310D; 310E; 310F; 310G) made of a ceramic material and having a spherical shape, wherein at least two of the plurality of resonators (120; 220A; 310A; 310B; 310C; 310D; 310E; 310F; 310G) are spaced according to a lattice constant (α) that defines a distance between a center of a first one of the resonators (120; 220A; 310A; 310B; 310C; 310D; 310E; 310F; 310G) and a center of a neighboring second one of the resonators, and wherein a ratio of a diameter (D) of the resonators to the lattice constant (α) is less than one. <EOS>