Aspects and embodiments relate to a plasmonic metamaterial structure, applications and devices including that plasmonic metamaterial structure, and a method of forming that plasmonic metamaterial structure. Aspects and embodiments provide a plasmonic metamaterial structure which comprises: a plurality of optical antenna elements. The plurality of optical antenna elements comprise: a first electrode, a second electrode and a plasmonic nanostructure element located between the first and second electrode to form an electron tunnelling junction between the first and second electrodes. The plurality of optical antenna elements are configured such that the electromagnetic field of one optical antenna element spatially overlaps that of adjacent optical antenna elements and adjacent optical antenna elements are electromagnetically coupled to allow the plurality of optical antenna elements to act as a plasmonic metamaterial. Aspects and embodiments also provide devices including that plasmonic metamaterial structure, and a method of forming that plasmonic metamaterial structure. Aspects and embodiments recognise that the sensitivity of an electron tunnelling junction, coupled with provision of a plurality of optical antenna elements may provide a practical structure which can provide sensing platforms, modulation, light source and nanoscale light source devices and applications.

Provided is a plasma antenna. The plasma antenna includes a radiation portion formed by stacking a plurality of radiation disks generating plasma based on provided energy and radiating a signal using the generated plasma, an energy generation portion configured to provide the energy to at least one of the plurality of radiation disks, and a signal transmission portion configured to provide the signal to the at least one radiation disk provided with the energy. Therefore, it is possible to support multiple frequency bands.

Systems and methods are provided for redirecting electromagnetic radiation around an object. A first assembly, including a first interior wall and a first exterior wall enclosing a propellant gas, substantially encloses the object. A first control system is configured to energize the propellant gas to provide a first volume of plasma and control an electron number density of the first volume of plasma. The electron number density of the first volume of plasma is selected to minimize reflection of the electromagnetic radiation from the first exterior wall. A second assembly includes a second interior wall and a second exterior wall enclosing a propellant gas and is substantially concentric with the first assembly and substantially encloses the object. A second control system is configured to energize the propellant gas to provide a second volume of plasma and control an electron number density of the second volume of plasma.

An antenna device includes a ground conductor (1), a dielectric tube (2) containing an ionizing gas and passing through the ground conductor, whose folded-back portion (201) and both ends are disposed in different sides of the ground conductor, first electrodes (3, 4) disposed at both ends of the dielectric tube (2), a plasma excitation power supply connected to the first electrodes, bringing the ionizing gas into a plasma state; a second electrode (6) ring-shaped and disposed at the both ends side of dielectric tube (2) from the ground conductor (1), fitted to and in contact with the dielectric tube outer surface, a high frequency transmitter (7) supplying a high frequency signal to the second electrode (6), and a feed line (8) connecting the second electrode and the high frequency transmitter. Each end of the dielectric tube (2) is larger than the second electrode in the inner diameter.

A quantum atomic receiving antenna includes: a probe laser; a coupling laser; an atomic vapor cell that includes: a spherically-shaped or parallelepiped-shaped atomic vapor space and Rydberg antenna atoms that undergo a radiofrequency Rydberg transition to produce quantum antenna light from probe light such that an intensity of the quantum antenna light depends on an amount of radiofrequency radiation received by the Rydberg antenna atoms, the quantum antenna light including a strength, direction and polarization of the radiofrequency radiation; and a quantum antenna light detector in optical communication with the atomic vapor cell.

An antenna assembly may include an antenna element, a radome structure disposed proximate to the antenna element and including a plurality of plasma elements, a driver circuit operably coupled to the plasma elements to selectively ionize individual ones of the plasma elements, and a controller. The controller may be operably coupled to the driver circuit to provide control of plasma density of the individual ones of the plasma elements. The plasma elements may include respective enclosures. At least some of the enclosures may have at least two peripheral edge surfaces substantially fully contacted by corresponding peripheral edge surfaces of adjacent enclosures at at least one section along a longitudinal length thereof.

A quantum atomic receiving antenna includes: a probe laser; a coupling laser; an atomic vapor cell that includes: a spherically-shaped or parallelepiped-shaped atomic vapor space and Rydberg antenna atoms that undergo a radiofrequency Rydberg transition to produce quantum antenna light from probe light such that an intensity of the quantum antenna light depends on an amount of radiofrequency radiation received by the Rydberg antenna atoms, the quantum antenna light including a strength, direction and polarization of the radiofrequency radiation; and a quantum antenna light detector in optical communication with the atomic vapor cell.

An antenna comprising: a radio frequency (RF) coupler; a transceiver communicatively coupled to the RF coupler; a laser configured to generate a plurality of femtosecond laser pulses so as to create, without the use of high voltage electrodes, a laser-induced plasma filament (LIPF) in atmospheric air, wherein the laser is operatively coupled to the RF coupler such that RF energy is transferred between the LIPF and the RF coupler; and wherein the laser is configured to modulate a characteristic of the laser pulses at a rate within the range of 1 Hz to 1 GHz so as to modulate a conduction efficiency of the LIPF thereby creating a variable impedance LIPF antenna.

An antenna assembly may include an antenna element, a radome structure disposed proximate to the antenna element and including a plurality of plasma elements, a driver circuit operably coupled to the plasma elements to selectively ionize individual ones of the plasma elements, and a controller. The controller may be operably coupled to the driver circuit to provide control of plasma density of the individual ones of the plasma elements. The plasma elements may include respective enclosures. At least some of the enclosures may have at least two peripheral edge surfaces substantially fully contacted by corresponding peripheral edge surfaces of adjacent enclosures at at least one section along a longitudinal length thereof.

In an antenna including a dielectric window and a slot plate provided on one surface of the dielectric window, in a case where a reference position g is a center position in a width direction of each slot S and a center position in a length direction in the slot plate, the reference position g of each slot is located on a virtual circle centered on a center of gravity G0, and line segments connecting the reference positions g of the slots S and virtual point G1 to which the slots belong are located radially from a virtual point G1, angles (1 to 4) between adjacent line segments are equal to each other, and angles (1 to 4) formed by the length directions of the slots S at the reference positions g and the line segments to which the slots belong are equal to each other.