Abstract: The invention is directed to a dual-frequency stacked patch antenna. In one embodiment, the antenna comprises a pair of electrically conductive, nested, tub-like structures and a feed surface. The edges of the tub-like structures and the feed surface define a surface that is adapted to be conformal to an application surface that defines a cavity in which the antenna is positioned. The edges of the tub-like structures and the edge of the feed surface define a pair of slots for receiving and/or transmitting two signals with different center frequencies. Located and extending throughout each of the slots is a slot modification structure comprised of inter-digitated fingers that provide capacitive loading and enhance the low observability of the antenna.

Abstract: The invention is directed to a crossed-dipole antenna structure that, in one embodiment, is comprised of: (a) a first planar dielectric substrate with a feed portion and an antenna portion that supports a first dipole antenna and (b) a second planar dielectric substrate that supports a second dipole antenna or substantial portion of such an antenna. The first and second planar dielectric substrates are positioned substantially perpendicular to one another and so as to form a crossed-dipole antenna from the first and second dipole antennas. The feed portion of the first planar dielectric substrate is electrically and mechanically connected to the second planar substrate by a plurality of solder joints established in the corners defined by the intersections of the first and second planar dielectric substrates.

Abstract: A radio frequency reconfigurable lens is provided. In particular, a lens comprising at least two opposed frequency selective surface sheets is provided. A relative phase shift may be imparted to an incident radio frequency wave by varying the distance between at least some of the unit cells of a first of the FSS sheets and adjacent unit cells on a second of the FSS sheets. In order to provide a desired phase taper across the width of a lens, and/or to provide different phase shift amounts, pairs of FSS surfaces having controllable columns or rows can be cascaded together. According to an additional aspect of the present invention, radio frequency waves can be scanned by cascading multiple tunable stages. The present invention also provides a radio frequency shutter.

Abstract: A radio frequency reconfigurable lens is provided. In particular, a lens comprising at least two opposed frequency selective surface sheets is provided. A relative phase shift may be imparted to an incident radio frequency wave by varying the distance between at least some of the unit cells of a first of the FSS sheets and adjacent unit cells on a second of the FSS sheets. In order to provide a desired phase taper across the width of a lens, and/or to provide different phase shift amounts, pairs of FSS surfaces having controllable columns or rows can be cascaded together. According to an additional aspect of the present invention, radio frequency waves can be scanned by cascading multiple tunable stages. The present invention also provides a radio frequency shutter.

Abstract: Method and apparatus for providing a configurable circuit are disclosed. In addition, method and apparatus for providing a phased array antenna having an integrated configurable circuit are provided. According to the present invention, at least a first component of a configurable circuit is formed on a first substrate. At least a second component of a configurable circuit is formed on at least a portion of a moveable cantilever formed from a second substrate. The first and second substrates are registered with one another to form a completed configurable circuit. According to the present invention, a configurable circuit may comprise a variable capacitor or a switch. In addition, a configurable circuit may be used in connection with phase shifting a radio frequency signal provided to an element of a phased array antenna.

Abstract: Method and apparatus for providing a configurable circuit are disclosed. In addition, method and apparatus for providing a phased array antenna having an integrated configurable circuit are provided. According to the present invention, at least a first component of a configurable circuit is formed on a first substrate. At least a second component of a configurable circuit is formed on at least a portion of a moveable cantilever formed from a second substrate. The first and second substrates are registered with one another to form a completed configurable circuit. According to the present invention, a configurable circuit may comprise a variable capacitor or a switch. In addition, a configurable circuit may be used in connection with phase shifting a radio frequency signal provided to an element of a phased array antenna.

Abstract: An antenna apparatus that includes a beam control system and a beam collimating system having a compound curve antenna structure is provided. The compound curve antenna structure can be two-dimensional or three-dimensional. In one embodiment, the curve is parabolic and the compound curve antenna structure includes first and second parabolic reflector sections that are spaced from each other. A feed array of the beam control system is disposed therebetween at the base ends of the two parabolic reflector sections. When the compound curve antenna structure is three-dimensional, the two parabolic reflector sections are part of a body of revolution. The control system also includes memory storage that stores predetermined data related to controlling activation of each of a plurality of feed elements of the feed array. The predetermined data is based on information obtained using a reference beam with the compound curve antenna structure.

Abstract: An antenna apparatus that includes a beam control system and a beam collimating system having a compound curve antenna structure is provided. The compound curve antenna structure can be two-dimensional or three-dimensional. In one embodiment, the curve is parabolic and the compound curve antenna structure includes first and second parabolic reflector sections that are spaced from each other. A feed array of the beam control system is disposed therebetween at the base ends of the two parabolic reflector sections. When the compound curve antenna structure is three-dimensional, the two parabolic reflector sections are part of a body of revolution. The control system also includes memory storage that stores predetermined data related to controlling activation of each of a plurality of feed elements of the feed array. The predetermined data is based on information obtained using a reference beam with the compound curve antenna structure.

Abstract: A deployable reflector for an electronically scanned reflector antenna is provided. The deployable reflector may be confined to a relatively small volume for transportation of the reflector to a deployment site. Upon deployment, the reflector of the present invention forms a relatively large reflector surface, having a precisely controlled surface geometry. The reflector generally includes a plurality of panel members interconnected to a plurality of ribs interconnected to an extendable boom. The antenna reflector of the present invention is particularly well suited for a space-based antenna, where a reflector that can be collapsed into a small volume for transport and deployed to form a large reflector surface having high gain is desirable.

Abstract: A method an apparatus for calibrating an electronically scanned reflector (ESR) antenna to compensate for mechanical distortions in a reflector and feed thereof first determines displacement values for a multitude of points on the reflector and the feed. The displacement values are then analyzed to determine the types of distortion, if any, that are present within the ESR antenna system. Compensation values are then determined for each of a plurality of beam positions based on the type(s) of distortion identified. The compensation values are stored in a lookup table for later use in generating antenna beams in the corresponding beam position.

Abstract: An antenna apparatus for generating transmit signals, receiving return signals based on the transmit signals, and/or receive transmitted signals from other sources is provided. The antenna apparatus includes a beam forming system and a beam collimating system. The beam forming system includes an array of feed elements. Each feed element can be used to generate more than one primary beam, either substantially at the same time or at different times. A secondary beam is developed from the primary beam using the collimating system. The secondary beam constitutes the transmit signal. The feed elements have relatively low gain, the spacing between them is no greater than about one wavelength, and they are relatively small in size to reduce beam-to-beam cross over loss. The beam forming system also includes a control system for energizing different feed elements using the same transmit/receive modules.