Abstract:
A cavity-backed slot antenna whose cavity has an artificial magnetic conductor (AMC) disposed therein, the AMC being loaded with active reactive elements. The active reactive elements are preferably formed by Non-Foster Circuits (NFCs).
Abstract:
An active artificial magnetic conductor includes an array of unit cells, each unit cell including a top face, at least one wall coupled to the top face, a base coupled to the at least one wall, and a crossed slot in the top face. The top face, the at least one wall, and the base form a cavity and are conductive.
Abstract:
A circularly polarized artificial impedance surface antenna (AISA) includes an impedance modulated substrate having a modulated scalar impedance to a surface wave traversing a top surface of the substrate, wherein the impedance modulation has a plurality of intertwined lines of constant impedance, and wherein each line of constant impedance follows a spiral elliptical path.
Abstract:
A dielectric artificial impedance surface antenna (DAISA) including a first dielectric with a thickness, the first dielectric thickness varying to provide a modulated impedance to a signal traversing the first dielectric, the first dielectric having a first surface and a second surface opposite the first surface, and a transparent conductive material coating the second surface.
Abstract:
An active artificial magnetic conductor includes a ground plane and an array of unit cells coupled to the ground plane. Each unit cell includes a low impedance shunt coupled to the ground plane and an impedance element coupled to the low impedance shunt. A plurality of non Foster circuits are coupled in two different directions between impedance elements of adjacent neighboring unit cells in the array of unit cells.
Abstract:
A method for fabricating and installing an artificial impedance surface antenna (AISA) includes locating a substantially flat surface having a line of sight to a satellite or satellites of interest, determining an angle θo between a normal to the substantially flat surface and a direction to the satellite or satellites of interest, selecting an antenna superstrate from a pre-fabbed stock of antenna superstrates, the selected antenna superstrate configured for having a peak radiation within two (2) degrees of the angle θo, laminating the selected antenna superstrate to an antenna substrate to form the AISA, and mounting the AISA on the substantially flat surface.
Abstract:
An apparatus for measuring material properties of a material under test includes a transmission line, a tunable cavity within the transmission line having a ground plane at an end of the tunable cavity, and a voltage-tunable reactive grid adjacent a beginning of the tunable cavity.
Abstract:
An active artificial magnetic conductor includes an array of unit cells, each unit cell including a top face, at least one wall coupled to the top face, a base coupled to the at least one wall, and a crossed slot in the top face. The top face, the at least one wall, and the base form a cavity and are conductive.
Abstract:
An active artificial magnetic conductor includes an array of unit cells, each unit cell including a top face, at least one wall coupled to the top face, a base coupled to the at least one wall, and a crossed slot in the top face. The top face, the at least one wall, and the base form a cavity and are conductive.
Abstract:
A system for measuring properties of a surface under test with surface waves includes a surface wave network including a dielectric substrate, a reactive grid of a plurality of metallic patches on a first surface of the dielectric substrate, a plurality of electronic nodes on the first surface of the dielectric substrate, and a ground plane on a second surface of the dielectric substrate permeable to RF fields of the surface waves, and a controller configured for causing a respective one of the electronic nodes to transmit at least one surface wave and configured for collecting data for signals received by at least one other of the plurality of electronic nodes.