Abstract: Feed horn apparatus for use in a multiple-feed antenna system. The present invention comprises a corrugated feed horn and an antenna array or cluster of feed horns arranged in a hexagonal lattice pattern. The feed horn comprises a hexagonal aperture formed by a circular-to-hexagonal transition section a corrugated section disposed adjacent to the circular-to-hexagonal transition section, a tapered section disposed adjacent to the corrugated section, and an input section having an input/output port disposed adjacent to the tapered section. The corrugated feed horn has good beam pattern symmetry, low cross-polarization, and sidelobe levels, along with an increased horn aperture area. As a result, the efficiency of the corrugated feed horn is improved by transitioning from a circular to the hexagonal aperture.

Abstract: A multi-wave-reflector antenna dish simultaneously receives signals from different satellites. The antenna dish comprises a reflector with a superquadric projected aperture and a plurality of LNBF modules. The reflector is formed through process including, projecting the superquadric on the paraboloid, projected aperture cutting and surface distortion of the aperture based on the generalized diffraction synthesis technique. In addition to reflecting signals from satellites, it also generates focusing waves sharing similar radiation patterns and horizontal gain with incoming waves on the focal plane, finally to be received by the LNBF modules.

Abstract: A dielectric slab is arranged on one surface of a ground plane to form a transmission guide for transmitting an electromagnetic wave along the surface from one end to the other end between the dielectric slab and the ground plane. A perturbation is loaded on the dielectric slab to leak the electromagnetic wave from the surface of the dielectric slab. A feed supplies an electromagnetic wave to one end of the transmission guide formed by the ground plane and dielectric slab. A dielectric layer is interposed between the ground plane and the dielectric slab, and has a lower permittivity than that of the dielectric slab.

Abstract: Antennas and multiplexer structures are provided for establishing individual communication links with satellites that are located at geostationary positions in close angular proximity to one another. The antenna includes individual wave-guides where at least one of the wave-guides has a decreased dimension such that the wave-guides may be spaced in close proximity to each other to communicate with the satellites. For example, in one embodiment, the antenna includes at least one wave-guide that is a hollow metallic structure filled with a dielectric material. The dimensions of this wave-guide can be altered by changing the dielectric material used to fill the wave-guide. By using a dielectric material having an appropriate dielectric constant, the dimension of the wave-guide can be configured to allow the wave-guide to be spaced in close proximity to the other wave-guide.

Abstract: A waveguide slot array antenna system, for use with a communications system 30 disposed on a satellite. The waveguide slot array antenna system comprises a feed waveguide having an input port and multiple output ports, a waveguide slot array having a plurality of slots formed therein that is coupled to the feed waveguide, and a waveguide lens disposed adjacent to the waveguide slot array. The phase of each contributing radiating waveguide is controlled to achieve radiation pattern shaping. Inner dimensions of the rectangular waveguides are designed to provide a phase velocity inside each waveguide that results in the appropriate radiated phase at the output of the waveguides. The phase radiated by each rectangular waveguide is determined by design, and the radiation pattern that results from the combined contributions of the array can be shaped to produce a complex radiation contour.

Abstract: In a primary radiator, a dielectric plate is fixed to the interior of a hollow first waveguide having, at one end, an opening shaped like a regular square, and is substantially orthogonal to two parallel sides of the opening. A second waveguide of rectangular cross section is coaxially connected to the other end of the first waveguide. A pair of probes are disposed at an angle of approximately 45° with respect to the dielectric plate so as to protrude from flat inner wall surfaces of the second waveguide toward the center axis.

Abstract: Methods of fabricating air-filed true-time-delay, continuous transverse stub array antenna. A plurality of extruded sections that are physically independent of one another are fabricated. The plurality of extruded sections are arranged in a predefined pattern defining the structure of the array antenna. Adjacent surfaces of the extruded sections form waveguides of the array antenna. The plurality of extruded sections are joined together at their respective ends to form the array antenna. The plurality of extruded sections may be joined using a plurality of end plates. The plurality of extruded sections and end plates may comprise metal or plastic. If the extruded sections are plastic, they are metallized 44 using a process such as vacuum deposition, electroless plating, or lamination during the extrusion process. The end plates are sealed to the extruded sections to form the array antenna structure.

Abstract: A satellite broadcast system and method, particularly useful for television signals, allows for local as well as nationwide broadcast service by allocating greater satellite resources to the more important local service areas. This is accomplished by broadcasting a non-uniform pattern of local service beams and designing the system to establish different service area priorities through factors such as the individual beam powers, sizes, roll-off characteristics and peak-to-edge power differentials. Frequency reuse is enhanced by permitting a certain degree of cross-beam interference, with lower levels of interference established for the more important service areas.

Abstract: An antenna suited for receiving/transmitting electromagnetic signals from/to at least two satellites, which are fixedly placed at points on the geostationary path, is waveguide or lens type, formed by a multitude of waveguiding channels, which for example can be rotationally symmetrically arranged about an axis. Signals from remote points, which arrive in directions somewhat deviating from the direction of the axis, e.g. in an angle &agr;in thereto, exit after being refracted in the antenna in a different direction, so that the angle &agr;ut on the exit side differs from the angle &agr;in on the entrance side. It is achieved by having all of the waveguiding channels form suitably adapted angles to the axis. For a concave antenna it can give an increased separation between the positions, to which signals from remote objects are refracted by the antenna. It results in, for example, large more efficient receiver horns being used for the same size of the antenna.

Abstract: A feeder horn intended particularly for two-way satellite communications equipment and including a central transceiver horn (10) and at least three separate measuring horns (11, 12, 13) placed symmetrically in relation to the feeder horn symmetry line (O), wherein all horns are produced mechanically in one and the same metal element (1) which includes a through-penetrating center opening (100) for the transceiver horn (10), a bottom-delimited opening (110, 130, 140) for each of the measuring horns (11, 12, 13), and a moat-like recess (104, 114, 124, 134) in the metal element (1) around each opening (100, 110, 120, 130) for insulating each horn electromagnetically in relation to other horns. The delimited opening (110, 120, 130) for each of the measuring horns in the metal element (1) is filled with dielectric material (1101, 1201, 1301).

Abstract: When a converter 14 is rotated via a rotation mechanism 17, the arrangement inclination angle of two primary radiators 15a and 16b can be adjusted in the range of 0 to 20 deg. with respect to an axis which is in parallel with the ground. Also the reception polarization angle due to probes of the primary radiators 15a and 15b can be adjusted in the range of 0 to 20 deg. while maintaining a preset difference in polarization angle among the satellites. Therefore, the arrangement inclination angle of the primary radiators 15a and 16b for respectively receiving signals from the two satellites, and the reception polarization angle in the primary radiators 15a and 15b can be simultaneously easily adjusted by rotating the converter 14 via the rotation mechanism 17.

Abstract: Antennas useable in all types of weather conditions are disclosed for use in various applications. The antenna is a flat array with either microstrip or slotted waveguide radiating elements. The radiating elements can be either transmitting or receiving elements for the array, or can be two arrays, each dedicated to one half of the transmission link. The array is covered with a radome to prevent water droplets, ice, or snow from forming on the antenna surface, thus allowing beam launching or beam reception at the antenna surface. The antennas can be used in a wide field of applications, including microsatellite communications links. Also disclosed is a microstrip, dual-band phased array antenna having a top dielectric including an antenna array patch directly coupled to a receive feed network and a lower dielectric having a transmit feed that is coupled to the antenna array patch through an intermediate metallization layer having coupling slots.

Abstract: A coaxial cavity antenna including a cylindrical inner conductor sized for propagation of electromagnetic signals in a preselected frequency range. The coaxial antenna also includes a cylindrical outer conductor positioned coaxial with the inner conductor, and having a diameter larger than the inner conductor. The outer conductor has an aperture ring disposed at an end of the outer conductor. The outer conductor is positioned with respect to the inner conductor to form a cavity between the inner conductor and the outer conductor. The cavity is sized for propagating electromagnetic signals in the preselected frequency range. The coaxial cavity antenna also includes a plurality of aperture teeth radially oriented and disposed around the aperture ring, and an iris ring positioned inside the cavity at a predetermined distance from the aperture ring.

Abstract: A microwave radiating element including first and second means for conveying electromagnetic waves in respective first and second frequency bands, wherein the first and second means are coaxial.

Abstract: An antenna device comprising a plurality of directional antennas which are aligned on the same axis in one direction and which are also arranged in a manner that the main radiation directions of the plurality of directional antennas deviate from each other in a direction orthogonal to the direction. Hence, a drop in directivity due to the array factor can be prevented and radiation characteristics in the plane orthogonal to the direction is expanded.

Abstract: The present invention provides a low-cost, steerable antenna formed with a dielectric medium separating a pair of conductive plates and a centrally located signal feed. Switches selectively interconnect the conductive plates through the dielectric medium in patterns, which determine the direction of operation of the antenna. The directionality of the antenna may be fixed or rapidly changed, depending upon the application.

Abstract: An antenna feed system capable of simultaneously receiving and transmitting in multiple frequency bands is disclosed. In one embodiment, the feed system comprises a dielectric loading rod, an inner cylindrical waveguide, and one or more outer cylindrical waveguides. The dielectric loading rod lies along a central axis, as do the inner waveguide and outer waveguides. The axis of the inner waveguide and the rod may coincide. Each waveguide may be configured to receive and transmit a different frequency band simultaneously with the other waveguides. In addition, the axes of the outer waveguides also coincide with the central axis. The antenna feed system may further comprise one or more junctions disposed to propagate electromagnet radiation into and out of the inner waveguide and outer waveguides. A method and kit for simultaneously receiving and transmitting in multiple frequencies are also disclosed.

Abstract: It is an object of the invention to provide a connection structure for connecting the dielectric strip of an NRD guide with a metal waveguide, in which the conversion loss (connection loss) for high-frequency signals is reduced, and in which the NRD guide as well as the millimeter wave integrated circuit in which the NRD guide is incorporated can be made smaller. A non-radiative dielectric waveguide is made by arranging a dielectric strip for propagating high-frequency signals between parallel planar conductors arranged at a spacing of not more than half the wavelength of a high-frequency signal, a conductive member being arranged at an end face of a terminal end of the dielectric strip. An aperture is formed in at least one of the parallel planar conductors at a location where the electrical field of an LSM mode stationary wave propagating along the dielectric strip becomes largest. An open terminal end of a metal waveguide is connected to this aperture.

Abstract: The present invention provides a planar antenna which has a decreased transmission loss, improved aperture efficiency, increased productivity, and reduced cost when it is used in a high-frequency band such as submillimeter and millimeter wave bands, and which allows multibeam scanning and electronic-beam scanning with a thin, simple structure. According to one aspect of the present invention, the planar antenna includes a planar ground conductor, a plurality of radiating dielectrics arranged in parallel and at established intervals on a surface of the ground conductor, and a plurality of perturbations for radiating an electromagnetic wave.

Abstract: A high performance phased array antenna system for receiving satellite communication signals, with a structural top layer formed as a perforated plate (or solid plate made of very low loss plastic material), a middle layer functioning as the single layer antenna aperture layer, preferably in the form of a single layer printed circuit board on which is formed an array of antenna elements and plurality of stripline feed network circuits, each combining in-phase outputs from several adjacent antenna elements, the bottom layer functioning as the ground plane for the antenna aperture layer and also including a single level waveguide combining network for combining in-phase outputs from stripline feed network circuits electromagnetically coupled to respective transition probe holes of the waveguide combining network. Each antenna element is preferably a dual polarization octagonal patch antenna element disposed on a common surface of the antenna aperture layer.

Abstract: An antenna device for emitting and/or receiving electromagnetic radiation, such as radar radiation in a car radar apparatus is provided. Sweeping is realized by means of a fixed feeder and a rotatable reflector. The reflector is driven by a drive motor and its motion is monitored by a tachometer. The drive motor and the tachometer are constituted by so-called flag motors which are mutually motionally coupled to each other by mechanical means.

Abstract: An antenna suited for receiving/transmitting electromagnetic signals from/to at least two satellites, which are fixedly placed at points on the geostationary path, is waveguide or lens type, formed by a multitude of waveguiding channels, which for example can be rotationally symmetrically arranged about an axis. Signals from remote points, which arrive in directions somewhat deviating from the direction of the axis, e.g. in an angle &agr;in thereto, exit after being refracted in the antenna in a different direction, so that the angle &agr;ut on the exit side differs from the angle &agr;in on the entrance side. It is achieved by having all of the waveguiding channels form suitably adapted angles to the axis. For a concave antenna it can give an increased separation between the positions, to which signals from remote objects are refracted by the antenna. It results in, for example, large more efficient receiver horns being used for the same size of the antenna.

Abstract: An antenna device includes a dual polarized quad-ridge antenna horn having an electrically conductive conduit with first and second opposite ends along a horn axis. Four electrically conductive ridges are carried on an inner side of the electrically conductive conduit. A printed wiring board including a dielectric substrate is connected across the first end of the dual polarized quad-ridge antenna horn and transversely to the horn axis. Furthermore, an electrically conductive pattern is formed on the dielectric substrate and defines feed elements for the dual polarized quad-ridge antenna horn.

Abstract: An antenna for providing a first antenna pattern at a first frequency of operation and a second antenna pattern at a second frequency of operation from first and second RF signals, respectively. The antenna included a horn which is dimensioned to generate the first antenna pattern from the first RF signal. A conduit is located within the horn and is configured to propagate the second RF signal in a waveguide mode. A corrugated rod having a first and a second portion is associated with the conduit. The first portion of the rod is located inside the conduit and the second portion of the rod protrudes from the conduit into the horn. The rod is configured to be responsive to the second RF signal and is operative to transition the second RF signal from a waveguide mode to a surface wave mode and propagate the second RF signal in a surface wave mode along the rod. The rod is configured to generate a second antenna from the second RF signal propagating in a surface wave mode.

Abstract: An optically controlled frequency selective surface (FSS) includes an electrically conductive layer having an array of radio frequency scattering elements such as slots formed in an electrically conductive layer or loops mounted to a substrate. Photonically controlled elements, such as photo-diodes, photo-transistors, and other photo-electronic devices, are connected across each of the scattering elements. Electromagnetic characteristics of the FSS, including resonant frequency, impedance, and the pass/stop band, may be modulated by controlling the degree of illumination of the photonically controlled elements.

Abstract: A microwave antenna (10) is formed from a stack of generally planar elements (14-122) forming an array of horns (12) communicating with waveguides (38). The generally planar elements (14-22) are of metallized plastics. Each of these elements (14-22) has a given overall thickness which is constituted by a membrane of relatively small thickness formed (typically by vacuum forming) into a corrugated shape.

Abstract: A high power TM01 mode radio frequency antenna. The inventive antenna comprises a conical horn for receiving an electromagnetic input signal and radiating an output signal in response thereto. An inner window is disposed within the conical horn. An outer window is mounted at an output aperture of the conical horn in alignment with the inner window. The antenna has a gradual taper from a waveguide input to the aperture over a cone angle of 45 degrees. The outer window is mounted at the aperture in concentric alignment with the inner window. For an optimal compact design, the inner and outer windows are of polycarbonate construction.

Abstract: A multi-feed, multi-band antenna includes a parabolic dish reflector, a plurality of four-port feeds, and may also include one or more orthomode two-port feeds. Each four-port feed is constructed to conduct multiple frequency bands and multiple polarized RF signals within each of the bands. A mounting structure mounts each of the feeds at a different position in a line and in a plane parallel to the rim of the reflector. The four-port feeds are of a size which allows them to be mounted adjacent each other and two degrees apart. The mounting structure positions the feeds at a distance F from the reflector. The diameter D of the reflector and the distance F have a relationship such that F/D is less than approximately 0.5.

Abstract: A modular antenna has a primary radiating aperture which can either be an array of radiating elements or a passive reflector. In regards to the array of radiating elements, a feed network interfaces with the radiating elements to form the modular antenna array. The feed network has a number of output ports wherein each output port of the feed network is adapted to interface with each feed port of the radiating elements. The feed network can be placed at various locations along the antenna array to change to radiation characteristics of the antenna array. When passive reflector is used, a modular feed interfaces with the waveguide. The feed module controls the sector radiation pattern. The vertical reflector surface controls the elevation radiation pattern. The feed module can consist either of an antenna array or a single element utilizing beam shaping.

Abstract: An injection molded phased array antenna system such as may advantageously employed on satellites. The antenna system comprises a plurality of metal plated, injection molded plastic horn radiating elements respectively coupled to a plurality of metal plated, injection molded plastic orthomode junctions that produce a corresponding plurality of vertically and horizontally polarized outputs. A metal plated, injection molded plastic vertical and horizontal beamforming networks is coupled to outputs of the plurality of orthomode junctions that establish unique phases and amplitudes that produce two separate outputs associated with two independent beams.

Abstract: The present invention relates to a transmission or reception device. The device comprises several layers having openings such that the stack thereof produces one or more antennas. Microwave circuits are implanted on internal layers.

Abstract: A dual-linearly polarized multi-mode rectangular horn includes a step junction in each of the two orthogonal planes for producing a desired amount of the higher order TE.sub.30 mode signal along with the dominant order TE.sub.10 mode signal for both of the vertical and horizontal polarization signals. The rectangular horn further includes a phasing section in each of the two orthogonal planes for causing the TE.sub.30 mode signal to be a desired amount of degrees out of phase with the TE.sub.10 mode signal at the aperture plane of the rectangular horn for both of the vertical and horizontal polarization signals. The rectangular horn is for use in a reconfigurable satellite array antenna.

Abstract: The invention comprises an array of radiating elements (1) to be used as a module in a phased-array radar antenna, the radiating elements consisting of waveguides of rectangular section. The radiating elements are disposed on a common surface (2), which causes the common surface to constitute a side wall of each radiating element. The radiating elements preferably consist of channel sections (3). This consequently yields a rigid construction, while the array can be realised in only a limited number of manufacturing operations.

Abstract: This invention is a compact and cost effective multiple-feed signal receiver for use in conjunction with a parabolic dish antenna to receive electromagnetic signals from more than one satellite clusters. The multiple-feed signal receiver has a multi-layer structure to integrate circuit boards for different frequency bands or the same frequency band for different signal processing within a limited cross-section and to isolate these boards from signal interference with one another.

Abstract: Provided coaxially inside a first waveguide is a second waveguide, so as to form a coaxial waveguide. The first waveguide for the passage of a low-frequency band signal (f.sub.L signal) functions as the outer conductor of the coaxial waveguide while the second waveguide for the passage of a high-frequency band signal (f.sub.H signal) serves as the center conductor of the coaxial waveguide. Feeders for f.sub.L are provided so that they penetrate through the wall of the first waveguide. Feeders for f.sub.H are provided so that they penetrate through both the first and the second waveguide walls. The distance between the first f.sub.L feeder and the first f.sub.H feeder and the distance between the second f.sub.L feeder and the second f.sub.H feeder are set at approximately one quarter of the wavelength of the f.sub.L signal. The distance between the first f.sub.H feeder and a reflector surface is also set at about one quarter of the wavelength.

Abstract: A true-time-delay corporate feed that minimizes both scan- and frequency-dependent variations in driving point impedance by realizing and exploiting a folded ensemble of intentionally mismatched E-plane tee junctions, E-plane steps, and E-plane bends that are used to form the antenna feed. A selected arrangement of E-plane tee junctions, E-plane steps, and E-plane bends are interconnected between a line-source interface that receives RF power and a plurality of line-source interfaces that couple the RF power to radiating stubs of a continuous transverse stub antenna array. The impedance of the individual mismatched components are set to be essentially constant and purely real, such that the feed network ensemble behaves as a multi-stage transformer, efficiently matching dissimilar radiator (load) and line-source (source) impedances over a broad range of operating frequencies and scan angles.

Abstract: This invention discloses a novel design for receiving electromagnetic signals broadcasted from at least two of satellite clusters and collected by a single dish antenna. At least two signal feeds are used to feed the signals to a processing circuit. The processing circuit performs signal selection, amplification, and frequency conversion. Corrective lens are used to ensure uniform wavefront of the electromagnetic signals received by the signal feeds located farther away from the focal point of the dish antenna. A convenient adjustment device is provided for adjustment of the relative positions of the signals feeds to the dish antenna.

Abstract: This application relates to a compact broadband horn antenna. The antenna has a septum in the horn adjacent one side thereof. One embodiment consists of abutting, wedge-shaped, dielectric members having conducting coatings. A particular feed arrangement has a primary segment partitioned into quadrants with each quadrant having a conducting septum extending forwardly into a secondary section, to provide field uniformity. In an embodiment useful at frequencies above 1 GHz the septum curves upwardly at the horn mouth and is supported by an absorbing structure located just above the mouth of the horn. The other end of the septum is supported at the horn feed and the septum is otherwise unsupported along its length.

Abstract: An electronically scanned antenna that is manufactured using semiconductor material and device fabrication technology. The antenna has a semiconductor substrate having a plurality of stubs projecting from one surface. The semiconductor substrate may be silicon, gallium arsenide, or indium phosphide, for example. A first conductive layer formed on the surfaces of the semiconductor substrate and along sides of the stubs so that the stubs are open at their terminus. The conductive layers form a parallel plate waveguide region. A diode array having a plurality of diode elements is formed in the semiconductor substrate that are disposed transversely across the semiconductor substrate and longitudinally down the semiconductor substrate between selected ones of the plurality of stubs. The diode array may comprise an array of Schottky or varactor diodes, for example.

Abstract: A microwave detector includes a horn antenna and cavity formed by covering a metallic film of a printed substrate with an opened bottom microwave circuit component, and further includes a mixer diode which is positioned at the feeding point of the horn antenna and sandwiched between the microwave circuit component and the printed substrate, the mixer diode including a mixer diode substrate having a first protruding portion at a first end of the mixer diode substrate and a second protruding portion at a second end of the mixer diode substrate, separate anode and cathode electrode patterns formed on a surface of the substrate which includes the protruding portions, and a beam-lead-type or flip-chip-type diode which is mounted to a surface of the mixer diode substrate near the center thereof, the beam-lead-type or flip-chip-type diode having an anode and a cathode which are surface mounted to the anode and cathode electrode patterns to form electrically conducting pathways therewith, wherein the first and second

Abstract: A passive microwave device combines energy from two microwave communication frequency bands into a common waveguide. Reciprocally, the device separates energy from two microwave frequency bands carried in a common waveguide into separate waveguides for each frequency band. The coupling is accomplished by means of probes that pass between the waveguides. The device can be used for the combination/separation of energy in the X-band and the Ku-band, wherein the Ku-band energy is coupled into/out of a square common waveguide by means of symmetrically positioned coaxial RF coupling probes. The coupling probes extend into both the common waveguide and also into rectangular Ku-band only waveguides. The X-band and Ku band are thus combined and/or separated passively for dual or multi-band antenna feeds in a compact, low cost package. The common waveguide is constructed to include a filter that substantially attenuates any Ku-band energy that would otherwise propagate towards the X-band input/output port.

Abstract: A phased-array antenna, particularly for the radar frequency range, comprising at least a predetermined number of transmit/receive radiator elements arranged linearly and/or matrix-shaped, a power distribution as well as a phase shifter network and a transmit/receive change-over arrangement. The transmit/receive change-over arrangement includes a serial feed comprising a waveguide with coupling in/coupling out locations disposed along its length and to which the phase shifter network, and possibly a further power distribution network, is coupled and also the transmitting/receiving arrangements are coupled. With this arrangement, an otherwise needed transmit/receive switch, for example, a circulator, is not necessary.

Abstract: An inverted boxhorn antenna array comprising a power divider that is constructed from a single metal piece and a flat metal sheet that is fastened to a rear surface of the power divider. The power divider is fabricated using a variety of waveguide junctions coupled between substantially identical inverted boxhorn subarrays. The junctions includes a central magic tee junction for coupling energy from an input port into the power divider. Alternating folded shunt and folded series tee junctions are used to transfer power coupled by way of the central series junction to the inverted boxhorn subarrays. Specially dimensioned folded shunt and series tee junctions are used in the inverted boxhorn subarrays. Waveguide matched loads are bonded in waveguides between each of the inverted boxhorn radiators of the subarrays. A fully functional antenna assembly includes a radome cover, a quadrature correction plate 18a, and a twist polarizer disposed in front of radiating elements of the inverted boxhorn antenna array.

Abstract: To obtain a high-performance antenna apparatus free from the shift of its focusing point, there are provided a plurality of pairs of horns, horns of each pair are arranged at opposite positions with respect to the center of the plurality of horns, and each pair of horns operates at a different frequency band.

Abstract: A low cost, compact, electronically scanned millimeter wave (MMW) lens enables the projection of a highly directional beam of Ka band millimeter wave (MMW) electromagnetic energy, while eliminating the need for mechanical movement of the lens. The present invention allows for the economical production and operation of the lens in the Ka and higher frequency ranges by exploiting waveguide technology. The waveguides of the present invention are tapered longitudinally resulting in a wider portion of the waveguide in electromagnetic communication with an interior cavity of the lens. The waveguide taper improves impedance matching between the waveguides and the lens cavity. The waveguides also include symmetric power dividers, located longitudinally within the waveguide aperture, ensuring port widths below .lambda..sub.g /2, thus, reducing or eliminating unwanted mode components which reduces sidelobe energy. This results in a low loss, low sidelobe steerable beam of MMW energy.

Abstract: Microwave tumor detection apparatus includes a probe having a working end arranged to contact tissue. Positioned in the probe is at least one rectangular waveguide each waveguide having an aperture at the working end of the probe. The waveguides constitute antennas tuned to receive microwave radiation emitted by the tissue opposite the working end of the probe. Each waveguide is coupled electrically and mechanically to a dedicated radiometer in the probe for detecting the temperature of tissue opposite that waveguide. These radiometers have thermally conductive casings which are mounted to a common heat sink and are insulated so that all of the radiometers have a uniform thermal distribution. Also, a thin thermally insulating interface pad may be located between the working end of the probe and the tissue contacted by the probe to prevent such contact from causing changes in the surface temperature of the tissue. A method of detecting breast tumors is also disclosed.

Abstract: A phased array antenna including a number of waveguide radiators in a power supply system. A calibration network provides a test pulse. By directly connecting the calibration network to the waveguide radiators, a more accurate calibration is obtained due to the processing of any phase and amplitude errors arising in the waveguide radiators in a calibration algorithm. The calibration network can be designed as a system of waveguides.

Abstract: An array antenna is located on an upper surface of a vehicle. The array antenna is oriented at a right angle to a radio wave blocking obstacle existing in a radio wave transmission path. A diffracted wave is effectively received at the shadowed portion where a direct wave is not transmitted because of the radio wave blocking obstacle. If the antenna dimension of its longitudinal direction is larger than that of the radio wave blocking obstacle, both direct wave and diffracted wave are received and therefore the reception power decrease caused by the radio wave blocking obstacle is further reduced.

Abstract: Systems and methods for two dimensional millimeter wave imaging are described. A system includes a spindle assembly defining a rotation axis; a waveguide assembly connected to the spindle assembly, the waveguide assembly including a first dielectric waveguide defining a first axis; and a grating assembly connected to the spindle assembly, the grating assembly including a plurality of sectors, each of the plurality of sectors including a varying period conductive grating pattern. A varying period of the varying period conductive grating pattern is a function of an angle defined by a rotational position of the grating assembly with regard to the rotation axis. The systems and methods provide advantages in that an image can be scanned quickly using an inexpensive system.

Abstract: An antenna design includes a plurality of radiating elements which radiate electro-magnetic energy, and feeders which feed the electromagnetic energy to the radiating elements. The feeders have a supply network substantially at the same level in the antenna thickness direction. In order to achieve a small antenna with adequate properties for radio link usage, the radiating elements are arranged next to the supply network in the thickness direction and include box horn antennas which have a step, characteristic of a box horn, in the plane of the magnetic field.