A satellite antenna heating system, includes a satellite antenna reflector defining a reflector fluid chamber and that includes a reflector wall. The reflector wall includes a first surface that is located adjacent the reflector fluid chamber, and a second surface that is located opposite the reflector wall from the first surface and provides an outer surface of the satellite antenna reflector, wherein the reflector fluid chamber is configured to channel a fluid through at least a portion of the satellite antenna reflector.

A metallic component including a metallic material and having a skin depth of greater than or equal to 1.0 m in a frequency range from 20-40 GHz, as calculated by:

[00001]$=\sqrt{\frac{2.Math.}{\left(2.Math..Math..Math.f\right).Math.\left({}_0.Math.{}_r\right)}}5.Math.0.Math.3.Math.\sqrt{\frac{}{{}_r.Math.f}}.$

In this equation, is skin depth in meters (m); is resistivity in ohm meter (.Math.m); f is frequency of an electromagnetic radiation in hertz (Hz); .sub.0 is permeability; and .sub.r is relative permeability of the metallic material. The metallic component may be a discrete metallic particle or a layer in a multilayer thin film.

Provided is an antenna including: a primary radiator configured to radiate radio waves; and a parabolic reflector configured to reflect the radio waves radiated by the primary radiator and has an aperture diameter reduced to be equal to or smaller than an aperture diameter with which no null points are generated in an antenna pattern in a semi-sphere where the radio waves are reflected and radiated.

The present disclosure provides a sub-wavelength structural material having compatibility of low detectability for infrared, laser, and microwave, which includes, from top to bottom, a metal type frequency selective surface layer I, a dielectric layer I, a metal type frequency selective surface layer II, a dielectric layer II, a resistive film, a dielectric layer III. Each of the metal type frequency selective surface layers is a sub-wavelength patch type array, and metal used by the metal type frequency selective surface layers has a characteristic of low infrared emissivity. The present disclosure modulates a phase by using a phase difference generated by patches with different sizes on the metal type frequency selective surface layer I, so as to control backscattering of incident electromagnetic waves to achieve compatibility of low detectability for laser and infrared, while the bottom three layers achieve absorption of microwave.

A metallic component including NiCr and having a skin depth of greater than or equal to 1.0 m in a frequency range from 20-40 GHz, as calculated by:

[00001]$=\sqrt{\frac{2.Math..Math.}{\left(2.Math..Math..Math..Math.f\right).Math.\left({}_0.Math.{}_r\right)}}503.Math..Math.\sqrt{\frac{}{{}_r.Math.f}}.$

In this equation, is skin depth in meters (m); is resistivity in ohm meter (.Math.m); f is frequency of an electromagnetic radiation in hertz (Hz); .sub.0 is permeability; and .sub.r is relative permeability of the NiCr metallic material. The metallic component may be a discrete metallic particle or a layer in a multilayer thin film.

An optically tunable metamaterial unit cell is provided for photonic switching. The cell is optically tunable and includes a dielectric substrate with upper and lower surfaces. The cell further includes arrays of metamaterial elements and a layer of photo-capacitive material. The arrays are disposed the upper surface of the dielectric substrate. The metamaterial is capable of reflecting electromagnetic radiation. The layer of photo-capacitive material overlaps the arrays of metamaterial elements. The photo-capacitive material is optically tunable.

An antenna structure to which the present invention is applied includes: a film that transmits visible light and has antennas formed thereon; a feeding part to which coaxial cables for feeding power to the antennas are connected; a flange that transmits visible light and is used for positioning the film from a visible side of equipment; and positioning structures for positioning the film from an invisible side of the equipment.

An antenna structure as an example of a structure including a transparent conductor includes: an antenna as an example of the transparent conductor; a film transmitting a visible light; a positioning structure configured to position the film from an invisible side of a ceiling as an example of a facility; and a flange transmitting the visible light and configured to position the film from a visible side of the ceiling and including a lens part at a position facing the positioning structure.

Optimizations are provided in the design and fabrication of a parabolic antenna reflector. In particular, a parabolic antenna reflector comprises an inner reflective face being formed in a parabolic shape and a first outer circumferential portion. The parabolic antenna also includes an outer face being formed in a different parabolic shape and a second circumferential portion. The first outer circumferential portion is coupled to the second outer circumferential portion to form an inner body between the inner reflective face and the outer face. This inner body includes a monopulse comparator waveguide. As a result, the monopulse comparator waveguide is embedded between the inner reflective face and the outer face. In some instances, this waveguide includes one or more bends. Additionally, in some instances, the parabolic antenna reflector is fabricated using additive manufacturing techniques such that the parabolic antenna reflector is a single printed unit.

A control device is provided for photonic switching. The device includes an optically tunable metamaterial unit cell. This structure includes a dielectric substrate; at least two arrays of metamaterial elements located on the top surface thereof, the metamaterial being capable of reflecting electromagnetic radiation, and a layer of photo-capacitive material overlapping the at least two arrays of metamaterial elements, the photo-capacitance of the photo-capacitive material being optically tunable; and a reflectarray or phased array system containing the unit cell.