Abstract: An orthogonal electrical coupling relies on electromagnetic coupling for the inner connection, as opposed to direct contact between conductors. A conductor on one of the lines is connected to a ground plane which is adjacent to a resonant slot. Microwave energy is coupled to the slot, thereby exciting the slot. A second conductor is on the opposite side of the ground plane from the first conductor. Microwave energy from the excited resonant slot passes to the second conductor, thereby allowing contactless interconnection between the first conductor and the second conductor. The coupling may emphasize certain modes of propagation relative to other possible modes of propagation. Specifically, the ground plane and slot may be enclosed in a cavity of a size such that the cavity does not support any natural mode propagation inside the cavity. Instead, the coupling may have a cavity in which a transverse electromagnetic (TEM) mode is propagated.

Abstract: A dual-polarization common aperture antenna having fully populated common aperture dual polarized arrays. The inventive antenna includes a first and second arrays of radiating slots disposed in a faceplate. The second array is generally orthogonal and therefor cross-polarized relative to the first array. The first array is waveguide fed and the second array is stripline fed. In the illustrative implementation, the first array and the second array share a common aperture. The common aperture is fully populated and each array uses the aperture in its entirety. The first and second arrays of slots are arranged for four-way symmetry. Each slot in the first array is a vertically oriented, iris-excited shunt slot fed by a rectangular waveguide and centered on a broad wall thereof. The second array is a standing wave array in which each slot is an air cavity backed slot fed by an inverted micro-stripline offset from a center thereof.

Abstract: A dual-polarization common aperture antenna having fully populated common aperture dual polarized arrays. The inventive antenna includes a first and second arrays of radiating slots disposed in a faceplate. The second array is generally orthogonal and therefor cross-polarized relative to the first array. The first array is waveguide fed and the second array is stripline fed. In the illustrative implementation, the first array and the second array share a common aperture. The common aperture is fully populated and each array uses the aperture in its entirety. The first and second arrays of slots are arranged for four-way symmetry. Each slot in the first array is a vertically oriented, iris-excited shunt slot fed by a rectangular waveguide and centered on a broad wall thereof. The second array is a standing wave array in which each slot is an air cavity backed slot fed by an inverted micro-stripline offset from a center thereof.

Abstract: An antenna and antenna excitation method. The inventive antenna includes a cylindrical array (20) of radiating elements. Each of the elements is mounted at a predetermined substantially transverse angle relative to a longitudinal axis. A circuit (30) is included for providing an electrical potential between at least two of the elements effective to scan a transmit or a receive beam of electromagnetic energy along an elevational axis at least substantially transverse to the longitudinal axis. In the illustrative embodiment, the array includes a stack of the planar, parallel, conductive, ring-shaped radiating elements, each of which is filled with ferroelectric bulk material. A second circuit (70) is included for exciting at least some of the elements to cause the elements to generate a transmit or a receive beam of electromagnetic energy off-axis relative to the longitudinal axis.

Abstract: A dielectric covered continuous slot (DCCS) antenna operable at RF frequencies. The antenna includes a conical or cylindrical dielectric radome structure having a nominal thickness equal to one quarter wavelength at a frequency of operation of the antenna. A conductive layer is defined on a contour surface of the radome structure, with a plurality of continuous slots defined in the conductive layer. The slots extend circumferentially about the longitudinal axis of the antenna and are spaced apart in a longitudinal sense. A serpentine end-fed signal transmission structure is disposed within the radome structure for carrying RF feed signals from an excitation end of the structure to a second end of the transmission structure.

Abstract: An orthogonal electrical coupling relies on electromagnetic coupling for the inner connection, as opposed to direct contact between conductors. A conductor on one of the lines is connected to a ground plane which is adjacent to a resonant slot. Microwave energy is coupled to the slot, thereby exciting the slot. A second conductor is on the opposite side of the ground plane from the first conductor. Microwave energy from the excited resonant slot passes to the second conductor, thereby allowing contactless interconnection between the first conductor and the second conductor. The coupling may emphasize certain modes of propagation relative to other possible modes of propagation. Specifically, the ground plane and slot may be enclosed in a cavity of a size such that the cavity does not support any natural mode propagation inside the cavity. Instead, the coupling may have a cavity in which a transverse electromagnetic (TEM) mode is propagated.

Abstract: A dielectric covered continuous slot (DCCS) antenna operable at RF frequencies. The antenna includes a conical or cylindrical dielectric radome structure having a nominal thickness equal to one quarter wavelength at a frequency of operation of the antenna. A conductive layer is defined on a contour surface of the radome structure, with a plurality of continuous slots defined in the conductive layer. The slots extend circumferentially about the longitudinal axis of the antenna and are spaced apart in a longitudinal sense. A serpentine end-fed signal transmission structure is disposed within the radome structure for carrying RF feed signals from an excitation end of the structure to a second end of the transmission structure.

Abstract: An antenna and antenna excitation method. The inventive antenna includes a cylindrical array (20) of radiating elements. Each of the elements is mounted at a predetermined substantially transverse angle relative to a longitudinal axis. A circuit (30) is included for providing an electrical potential between at least two of the elements effective to scan a transmit or a receive beam of electromagnetic energy along an elevational axis at least substantially transverse to the longitudinal axis. In the illustrative embodiment, the array includes a stack of the planar, parallel, conductive, ring-shaped radiating elements, each of which is filled with ferroelectric bulk material. A second circuit (70) is included for exciting at least some of the elements to cause the elements to generate a transmit or a receive beam of electromagnetic energy off-axis relative to the longitudinal axis.

Abstract: A multiple band reconfigurable reflecting antenna array and method for multiple band operation and beam steering. An array of dipole antennas is disposed on a multiple band high impedance surface. The antenna array is reconfigured by changing the length of the dipole elements, to thereby change the dipoles resonant frequency. At a given frequency band, small changes in dipole length allow to steer the reflected beam in the selected direction; whether large changes in dipole length permit to switch the operating frequency band. A method of broadening the bandwidth of a high impedance surface is also exposed.

Abstract: A radiator (10) comprising one or more centered longitudinal shunt slots (12) disposed in a rectangular waveguide (11) that are fed by corresponding offset ridge resonant irises (14). The offset ridge resonant irises that are centered on each respective slot. When multiple slots and offset ridge resonant irises are employed, adjacent irises are oriented opposite to one another.

Abstract: A compact high-performance antenna. The antenna includes a waveguide (16) for providing or receiving electromagnetic energy. A feed circuit (18, 106, 108, 110) provides or receives the electromagnetic energy to or from the waveguide (16). A radiating circuit (112, 114) provides or receives the electromagnetic energy to or from the feed circuit (18). One or more notches (120) in the feed circuit (108, 110) compensate for insertion phase errors in the electromagnetic energy. One or more tabs (18) in the radiating circuit (112, 114) compensate for radiation phase errors in the electromagnetic energy. In a specific embodiment, the antenna is a dipole antenna and includes an array of dipole cards. The radiating circuit (112, 114) includes first (112) and second (114) radiating circuits included in each of the dipole cards (14). The first (112) and second (114) radiating circuits include a plurality of quarter-wave stripline transformers (24).

Abstract: Disclosed is a common aperture dual polarization antenna array (30). This common aperture dual polarization antenna array (30) includes an antenna aperture (36) and a plurality of centered slot arrays (32) positioned within the antenna aperture (36). A plurality of notch dipole arrays (34) are positioned within the antenna aperture (36) and positioned substantially orthogonal to the plurality of centered slot arrays (32). A first feed guide (46) is coupled to the plurality of centered slot arrays (32) and a second feed guide (56) is coupled to the plurality of notch dipole arrays (34).

Abstract: Apparatus and methods for transitioning between opposite sides of adjacent stripline circuit boards. An orthogonal coaxial connection between opposite sides of the stripline circuit boards is provided wherein a center pin of a coax connector is disposed through the first stripline circuit board and the center trace of one of the stripline circuit boards and through the second board. The center pin is soldered or otherwise electrically attached to a small conductor island pad isolated from the ground plane of the second board and to the plated through hole. The ground of the coaxial connector is connected to the ground plane of the second board adjacent to the isolated conductor island pad.

Abstract: A low profile, compact microstrip-to-waveguide or stripline-to-waveguide transition. The end of the waveguide is terminated in a cavity backed slot defined in a groundplane formed on a dielectric substrate. The slot is excited by a microstrip or stripline conductor defined on the opposite side of the substrate. The conductor is terminated in a T-shaped junction including two opposed arms extending along the slot, each having a length equal to one-quarter wavelength at the center frequency of operation. A cavity covers the substrate on the conductor side, and is sized so that no cavity modes resonate in the frequency band of operation. The transition is matched by appropriate selection of the length of the slot and the length and position of the microstrip.

Abstract: A low profile, compact microstrip-to-waveguide transition which utilizes electromagnetic coupling instead of direct coupling. The end of the waveguide is terminated in a cavity backed slot defined in a groundplane formed on a dielectric substrate. The slot is excited by a microstrip line defined on the opposite side of the substrate, offset from the slot centerline. A cavity covers the substrate on the microstrip side, and is sized so that no cavity modes resonate in the frequency band of operation. The transition is matched by appropriate selection of the length of the slot and the length and position of the microstrip.

Abstract: A centered longitudinal series/series coupling slot disposed between a boxed stripline and a crossed rectangular waveguide comprising a plurality of longitudinal radiating slots. The centered longitudinal series/series coupling slot is disposed orthogonal to the longitudinal radiating slots of the crossed rectangular waveguide. The centered longitudinal series/series coupling slot is longitudinally disposed along the centerline of the boxed stripline in such a way the centered longitudinal slot interacts with the stripline mode and not with the rectangular waveguide mode (TE.sub.10 mode) in the boxed stripline. As a result of this, a highly efficient standing wave (or travelling wave) feed is provided using the centered longitudinal series/series coupling slot in the boxed stripline.

Abstract: A common aperture dual polarization array that comprises a vertical polarization antenna array that provides for vertical polarization, and horizontal polarization antenna array that provides for horizontal polarization. The vertical polarization antenna array is comprised of a flat plate shunt slot standing wave array that includes a plurality of sets of radiating slots configured in a staggered pattern that are laterally separated by an air gap. The horizontal polarization antenna array is comprised of a collinear array of radiating slots, a strip reflector, and a plurality of baffles that form a short backfire antenna array. The collinear slots are disposed orthogonal to the radiating slots of the vertical polarization antenna array.

Abstract: A dual polarization array that comprises horizontal polarization and vertical polarization arrays, combined with an efficient waveguide-fed standing wave feed array. The vertical polarization array comprises an offset, resonant, iris-fed, centered longitudinal-shunt-slot, standing wave array. The horizontal polarization array comprises a flared dipole fed by a longitudinal, shunt-slot, standing wave array. The waveguide-fed standing wave feed array is comprised of a plurality of waveguides that separately feed the horizontal polarization and vertical polarization arrays. The horizontal polarization array comprises a first plurality of radiating waveguides laterally disposed adjacent to each other that are separated by a first plurality of gaps. Each waveguide comprises a plurality of radiating flared dipoles disposed adjacent to a respective plurality of longitudinal radiating shunt slots.

Abstract: An interconnection between layers of stripline or microstripline in a multilayer microwave circuit assembly, through electromagnetic coupling. The adjacent layers (52 and 54) utilize a common ground plane layer (56), and a U-shaped coupling slot (64) is formed in the common ground plane. To eliminate undesirable coupling to other transmission line modes, the coupling slot is enclosed by a cavity (70) for each layer. The cavity size is selected so that no cavity mode exists, and to prevent formation of unwanted transmission modes. The "U" shape of the slot reduces the size of the cavity. The interconnection can be used with adjacent layers of stripline, microstrip line, or stripline and microstrip line.

Abstract: An array antenna which includes a first waveguide 12 coupled to a second waveguide 20 by an L-shaped coupling slot 30. The slot 30 has a first portion 32 orthogonal to a second portion 34 thereof thereby providing the unique L-shape. In a specific embodiment, the slot 30 is located with the first portion 32 along the centerline and longitudinal axis of the first waveguide 12 and the second portion 34 along the centerline and longitudinal axis of the second waveguide 20. The folded short, as well as the tapered section of prior designs can be eliminated by use of the L-shaped coupling slot of the present invention in the first and last positions of the coupling slot because a short can be placed at the L-shaped slot. Hence, the L-shaped coupling slot of the present invention provides a more compact planar antenna than that afforded by conventional designs.