Abstract: A wireless communication device includes an array of helical antennas on a substrate. Each helical antenna comprises a strain-relieved sheet with a conductive strip thereon, where the strain-relieved sheet and the conductive strip are in a rolled configuration about a longitudinal axis. The conductive strip is oriented at an angle ? with respect to a rolling direction so as to comprise a helical configuration about the longitudinal axis with a non-zero helix angle ?. The array exhibits a maximum gain of at least about 10 dB at a working frequency of at least about 0.1 THz.

Abstract: A wireless communication device includes an array of helical antennas on a substrate. Each helical antenna comprises a strain-relieved sheet with a conductive strip thereon, where the strain-relieved sheet and the conductive strip are in a rolled configuration about a longitudinal axis. The conductive strip is oriented at an angle ? with respect to a rolling direction so as to comprise a helical configuration about the longitudinal axis with a non-zero helix angle ?. The array exhibits a maximum gain of at least about 10 dB at a working frequency of at least about 0.1 THz.

Abstract: A chiral structure comprises an elongate strip in a rolled configuration about a longitudinal axis, where the rolled configuration is a helical configuration comprising a non-zero helix angle. The elongate strip comprises an amorphous or a polycrystalline material. A rolled-up structure with modulated curvature comprises a sheet comprising an amorphous or polycrystalline material in a rolled configuration about a longitudinal axis, where the sheet comprises a thickness t and the rolled configuration comprises an inner diameter D. An inner diameter-to-thickness ratio D/t of the rolled-up structure is no greater than about 40.