A metasurface may include a substrate layer and a two-dimensional array of metallic optical pillars arranged in parallel rows extending vertically relative to the substrate layer. Gaps between adjacent pillars form optical resonators and a tunable dielectric material is positioned in the optical resonators between the pillars. A reflective layer positioned between the substrate layer and the two-dimensional array of pillars may include a two-dimensional array of elongated rectangular reflector patches arranged in parallel rows with an electrical isolation gap between adjacent rows of reflector patches. The plurality of reflector patches may be arranged lengthwise within each row with an off-resonance gap between adjacent reflector patches. The reflector patches in adjacent rows may be offset with respect to one another, such that the off-resonance gaps between adjacent reflector patches in one row are not aligned with the off-resonance gaps between adjacent reflector patches in an adjacent row.

An antenna apparatus includes a first radiation area, a phase adjustment area and a second radiation area. The first radiation area is disposed opposite to the second radiation area. The first radiation area is connected to one end of the phase adjustment area. The other end of the phase adjustment area is connected to the second radiation area. The first radiation area includes a feeding point of the antenna apparatus. The second radiation area includes a ground point of the antenna apparatus. The phase adjustment area is used to adjust a phase of a signal fed by the feeding point, to change a direction of a space electromagnetic field formed by an electromagnetic signal radiated by each of the first radiation area and the second radiation area.

An antenna apparatus includes a first radiation area, a phase adjustment area and a second radiation area. The first radiation area is disposed opposite to the second radiation area. The first radiation area is connected to one end of the phase adjustment area. The other end of the phase adjustment area is connected to the second radiation area. The first radiation area includes a feeding point of the antenna apparatus. The second radiation area includes a ground point of the antenna apparatus. The phase adjustment area is used to adjust a phase of a signal fed by the feeding point, to change a direction of a space electromagnetic field formed by an electromagnetic signal radiated by each of the first radiation area and the second radiation area.

An antenna structure includes a radiative antenna element disposed in a first conductive layer, a reflector ground plane disposed in a second conductive layer under the first conductive layer, a feeding network comprising a transmission line disposed in a third conductive layer under the second conductive layer, and at least one coupling element disposed in proximity to a feeding terminal that electrically couples one end of the transmission line to the radiative antenna element. The coupling element is capacitively coupled with the feeding terminal.

An antenna structure includes a radiative antenna element disposed in a first conductive layer, a reflector ground plane disposed in a second conductive layer under the first conductive layer, a feeding network comprising a transmission line disposed in a third conductive layer under the second conductive layer, and at least one coupling element disposed in proximity to a feeding terminal that electrically couples one end of the transmission line to the radiative antenna element. The coupling element is capacitively coupled with the feeding terminal.

Foldable antenna devices formed on rigid substrates are provided. The substrate can be planar in an unfolded state, and a metal layer can be formed on the rigid substrate to act as an antenna element. The rigid substrate(s) can include mountain folds and valley folds, or hinges, such that the antenna device is foldable from an unfolded state to a fully folded state.

Foldable antenna devices formed on rigid substrates are provided. The substrate can be planar in an unfolded state, and a metal layer can be formed on the rigid substrate to act as an antenna element. The rigid substrate(s) can include mountain folds and valley folds, or hinges, such that the antenna device is foldable from an unfolded state to a fully folded state.

Foldable antenna devices formed on rigid substrates are provided. The substrate can be planar in an unfolded state, and a metal layer can be formed on the rigid substrate to act as an antenna element. The rigid substrate(s) can include mountain folds and valley folds, or hinges, such that the antenna device is foldable from an unfolded state to a fully folded state.

Foldable antenna devices formed on rigid substrates are provided. The substrate can be planar in an unfolded state, and a metal layer can be formed on the rigid substrate to act as an antenna element. The rigid substrate(s) can include mountain folds and valley folds, or hinges, such that the antenna device is foldable from an unfolded state to a fully folded state.

Antenna systems have a substrate and antenna on the substrate, where the antenna has a plurality of leg elements. The plurality of leg elements comprises a conductive ink and forms a continuous path. At least one of the plurality of leg elements is individually selectable or de-selectable to change a resonant frequency of the antenna, and leg elements that are selected create an antenna path length corresponding to the resonant frequency. In some embodiments, the antennas are energy harvesters.