Abstract: Method for dynamically optimizing radome (110) performance. The method can include the steps of sensing (405) at least one parameter defining a performance characteristic of the radome (110). At least one electrical characteristic of the radome (110) can responsively be varied to dynamically modify the performance characteristic. For example, the electrical characteristic can be varied by application of an energetic stimulus (440) to the radome (110).

Abstract: A method for dynamically modifying electrical characteristics of a radome (110). The method can interpose a radome (110) in the path of a radio frequency signal (140). At least one electrical characteristic of the radome (110) can be selectively varied by applying an energetic stimulus to dynamically modify a performance characteristic of the radome (110). Electrical characteristic can include a permittivity, a permeability, a loss tangent, and/or a reflectivity. The energetic stimulus can include an electric stimulus, a photonic stimulus, a magnetic stimulus, and/or a thermal stimulus.

Abstract: A radome (202) includes a dome wall (208) formed from a dielectric material wherein at least a portion of the dielectric material includes a plurality of magnetic particles (206). Radomes according to the invention can form dome walls of variable thickness, yet still have high radiation efficiency across a wide frequency band. Magnetic radomes utilize dielectrics including magnetic particles (206) to match the impedances between medium boundaries, such as an air to dome boundary.

Abstract: A crossed slot fed microstrip antenna (100). The antenna (100) includes a conducting ground plane (125), which has at least one crossed slot (125), and at least two feed lines (105). The feed lines (105) have respective stub regions (115) that extend beyond the crossed slot (125) and transfer signal energy to or from the crossed slot (125). The antenna (100) also includes a first substrate (150) disposed between the ground plane (120) and the feed lines (105). The first substrate (150) includes a first region and at least a second region, the regions having different substrate properties. The first region is proximate to at least one of the feed lines (105).

Abstract: A waveguide (100) including at least one outer surface (105, 110, 115, 120) defining a waveguide cavity (140) and at least one inner surface (130, 135) positioned within the waveguide cavity (140). The inner surface (130, 135) includes a frequency selective surface (FSS) having a plurality of FSS elements (145) coupled to at least one substrate. The substrate defines a first propagation medium such that an RF signal having a first wavelength in the first propagation medium can pass through the FSS (130, 135). The FSS (130, 135) is coupled to a second propagation medium such that in the second propagation medium the RF signal has a second wavelength which is at least twice as long as a physical distance between centers of adjacent FSS elements (145). The second wavelength can be different than the first wavelength.

Abstract: A slot fed microstrip antenna (100) provides improved efficiency through enhanced coupling of electromagnetic energy between the feed line (117) and the slot (106). The dielectric layer (105) between the feed line (117) and the slot (106) includes magnetic particles (114), the magnetic particles (114) preferably included in the dielectric junction region (113) between the microstrip feed line (117) and the slot (106). A high dielectric region is preferably also provided in the junction constant to further enhance the field concentration effect. The slot antenna (100) can be embodied as a microstrip patch antenna (200).

Abstract: Method for constructing a radome (110). The method can include the steps of providing a radome structure, wherein the radome structure can include at least one of a radome wall (115) and a radome frame (120). The radome structure can be impedance matched to an operational environment. The impedance match can be independent of the thickness and geometry of the radome structure.

Abstract: The present invention relates to a circuit for processing radio frequency signals. The resonant circuit includes a substrate. The substrate can be a meta material and can incorporate at least one substrate layer. A resonant line and at least one ground can be coupled to the substrate. An end of the resonant line can electrically shorted to the ground or electrically open with respect to ground. The substrate layer can include a first region with a first set of substrate properties and at least a second region with a second set of substrate properties. At least a portion of the resonant line can be coupled to the second region. The first and/or second set of substrate properties can be differentially modified to vary a permittivity and/or a permeability over a selected region. A third region can be provided with a third set of substrate properties as well.

Abstract: A slot fed microstrip patch antenna (300) includes a conducting ground plane (308), the conducting ground plane (308) including at least one slot (306). A dielectric material is disposed between the ground plane (308) and at least one feed line (317), wherein at least a portion of the dielectric layer (313) includes magnetic particles (324). The dielectric layer between the feed line (317) and the ground plane (308) provides regions having high relative permittivity (313) and low relative permittivity (312). At least a portion of the stub (318) is disposed on the high relative permittivity region (313).

Abstract: A feed structure (105) for a horn antenna (100). The feed structure can include a first waveguide (110) and a second waveguide (115) having a first portion at least partially disposed within the first waveguide. The second waveguide also can include a second portion intersecting a first wall (240) of the first waveguide. The first wall can include a first frequency selective surface (244) at an intersection (280) of the first wall and the second portion of the second waveguide. The first waveguide can be operatively coupled to a first horn section (130) and the second portion can be operatively coupled to a second horn section (135).

Abstract: An antenna system includes a ground plane and/or antenna elements forming an antenna array. A spatial filtering surface is positioned adjacent the antenna array through which electromagnetic radiation to or from the antenna array passes. The spatial filtering surface includes a dielectric substrate and a plurality of spaced, geometric configured, resonant elements printed on the dielectric substrate and configured and spaced from each other to have a resonant frequency to filter an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate. A dielectric filler is positioned between, above and below each resonant element printed on the dielectric substrate. A spatial filter taper transform is imparted when electromagnetic radiation passes therethrough. A standing wave is created between the ground plane and spatial filtering surface.

Abstract: A spatial filtering surface includes a dielectric substrate and a plurality of spaced, geometrically configured, resonant elements positioned on the dielectric substrate. The resonant elements form concentric rings that each attenuate any electromagnetic radiation passing therethrough a different amount wherein a spatial filter transform is imparted for tapering the magnitude and phase of a produced aperture field.

Abstract: An antenna (100) for microwave radiation including a first horn (135) which includes a plurality of corrugations (150). At least one of the corrugations (150) is formed of a frequency selective surface (FSS) (138). The FSS has a plurality of FSS elements (305) coupled to at least one substrate (310). The substrate (310) can define a first propagation medium such that an RF signal having a first wavelength in the first propagation medium can pass through the FSS (300). The FSS (300) is coupled to a second propagation medium such that in the second propagation medium the RF signal has a second wavelength which is at least twice as long as a physical distance between centers of adjacent FSS elements (305).

Abstract: A slot fed microstrip patch antenna (200) includes an electrically conducting ground plane (208), the ground plane (208) having at least one coupling slot (206) and at least a first patch radiator (209). An antenna dielectric substrate material (205) is disposed between the ground plane (208) and the first patch radiator (209), wherein at least a portion of the antenna dielectric (210) includes magnetic particles (214). A feed dielectric substrate (212) is disposed between a feed line (217) and the ground plane (208). Magnetic particles can also be used in the feed line (217) dielectric. Patch antennas according to the invention can be of a reduced size through use of high relative permittivity dielectric substrate portions, yet still be efficient through use of dielectrics including magnetic particles which permit impedance matching of dielectric medium interfaces, such as the feed line (217) into the slot (206).

Abstract: A circuit for processing radio frequency signals. The circuit includes a substrate where the circuit can be placed. The substrate can be a meta material and can incorporate at least one dielectric layer. A quarter-wave transformer and at least one ground can be coupled to the substrate. The dielectric layer can include a first region with a first set of substrate properties and a second region with a second set of substrate properties. Substrate properties can include a permittivity and a permeability. A substantial portion of the quarter-wave transformer can be coupled to the second region. The permittivity and/or permeability of the second region can be higher than the permittivity and/or permeability of the first region.

Abstract: Method for constructing a radome (110). The method can include the steps of providing a radome structure, wherein the radome structure can include at least one of a radome wall (115) and a radome frame (120). The radome structure can be impedance matched to an operational environment. The impedance match can be independent of the thickness and geometry of the radome structure.

Abstract: A circuit for processing radio frequency signals. The circuit can include a substrate board that has at least one dielectric layer (100) having a first set of substrate properties over a first region (102). The first set of substrate properties can include a first permittivity and a first permeability. A second region (140) can be provided with a set of second substrate properties. The second region can have a second set of substrate properties including a second permittivity and a second permeability. The second permittivity can be different than the first permittivity and/or the second permeability can be different than the first permeability. A first transmission line (102) having at least one discontinuity can be coupled to the second region (108). The discontinuity can include a bend, corner, non-uniformity, break in the transmission line, or a junction between the first transmission line and a second transmission line.

Abstract: A radome (202) includes a dome wall (208) formed from a dielectric material wherein at least a portion of the dielectric material includes a plurality of magnetic particles (206). Radomes according to the invention can form dome walls of variable thickness, yet still have high radiation efficiency across a wide frequency band. Magnetic radomes utilize dielectrics including magnetic particles (206) to match the impedances between medium boundaries, such as an air to dome boundary.

Abstract: A spatial filtering surface includes a dielectric substrate and a plurality of spaced, resonant dipole elements positioned on the dielectric substrate. Each dipole element has dipole ends and an associated diode for controlling amplitude taper and a reflection phase of an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate. Bias lines interconnect the dipole elements for conducting a bias current to a dipole element.

Abstract: A crossed slot fed microstrip antenna (100). The antenna (100) includes a conducting ground plane (125), which has at least one crossed slot (125), and at least two feed lines (105). The feed lines (105) have respective stub regions (115) that extend beyond the crossed slot (125) and transfer signal energy to or from the crossed slot (125). The antenna (100) also includes a first substrate (150) disposed between the ground plane (120) and the feed lines (105). The first substrate (150) includes a first region and at least a second region, the regions having different substrate properties. The first region is proximate to at least one of the feed lines (105).