Abstract: An array antenna system for forming multiple independently steered beams is described. The antenna system includes series or parallel feed circuits and phase shifters which are not disclosed directly in the signal path between the feed circuits and antenna elements included in the array antenna system.

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: A flat-plate dual band antenna element is described which comprises two superposed sets of excitation probes and apertures each of which operates in a different frequency band. These antenna elements are used in an array together with a plurality of single band elements to create a flat-plate, dual band array antenna that is low cost and permits monopulse alignment methods and distributed power amplification to be used. The geometric arrangement of the antenna elements is such that distribution networks for the excitation probes can be accommodated in the limited space available. Dual band flat-plate array feeds for a reflector antenna are also described. These use either a combination of the above mentioned dual band antenna elements and single band antenna elements or alternatively, two sizes of single band antenna elements.

Abstract: To control the temperature sensitivity of a ferroelectric microwave device, a microwave waveguide in the device is loaded with a modified ferroelecc material of reduced grain size less than 100 nm, preferably about 50 nm. The electrical properties of this material are less sensitive to temperature change. Thus, when a dc bias voltage is applied across the ferroelectric to tune the dielectric constant, changes in temperature will have a minimal effect on the desired tuning of the device.

Abstract: A low cost base station antenna for preventing insertion loss. In the antenna, a printed circuit board (PCB) has a power divider pattern including power divider terminals disposed on one side of the PCB. A conducting ground plate has therein rectangular apertures disposed in line as radiation elements respectively and electromagnetically coupled with each of the power divider terminals of the PCB and disposed to be separated from the PCB by a foamed dielectric sheet with a predetermined thickness so as to be insulated with respect to the power divider pattern. The power divider terminals of the PCB are disposed to terminate within the contour of the apertures and all the power divider terminals are disposed in one line and have a length being a quarter of wavelength. A cavity has a rectangular box with one side open and connected by its open side and by its edges to the ground plate so that all the apertures are disposed within contour of the capacity.

Abstract: A communication system for transferring data through the air over a relatively short fixed distance comprising a transmitting antenna which comprises a leaky coaxial cable for radiating electromagnetic energy modulated with data to be transferred; and a plurality of non-linear fixed beam array antennas for receiving the modulated electromagnetic energy from the leaky coaxial cable. The plurality of fixed beam array antennas are juxtaposed with the transmitting antenna such that the transmitting antenna extends at least partially through the near-field regions of the plurality of fixed beam array antennas. The communication system also comprises a selection means which determines which radio frequency output from the plurality of non-linear fixed beam array antennas exhibits the greatest radio frequency power and outputs that particular radio frequency output to a receiver.

Abstract: A feed device for a radiating element operating in dual polarization, for use especially in the field of space transmission, comprises a first feed line penetrating into a first cavity located beneath said radiating element, and a second feed line disposed in a configuration orthogonal to the first line and penetrating into a second cavity located in line with the first, a conductive part forming a coupling slot between the two cavities.

Abstract: A photonically controlled antenna array is made of a plurality of stacked light waveguides made of a material such as silicon whereon each of which one or more photonically controlled antenna elements are mounted. Light is injected into ones of the light waveguides and reflects therein until it is absorbed by the antenna elements mounted thereon due to the higher refractive index of silicon. When the photonically controlled antenna elements are illuminated they are switched to a conductive state and can transmit and receive electromagnetic signals. When no light is injected into the light waveguide the photonically controlled antenna elements are not illuminated and are in a non-conductive state wherein they cannot receive or transmit electromagnetic signals.

Abstract: A user terminal (110) which comprises an electrically-controllable back-fed antenna (300, FIG. 3) is used for the formation of single and multiple beams. The electrically-controllable back-fed antenna comprises an RF power distribution/combination network (310), electrically-controllable phase-shifting elements (320), a control network (440, FIG. 4) and radiating/receiving elements (360). The control network is coupled to the electrically-controllable phase-shifting elements and is used for controlling the dielectric constant of dielectric material contained within the electrically-controllable phase-shifting elements. In a preferred embodiment, phase-shifting elements comprise waveguide sections containing at least one dielectric material, and the dielectric material includes a ferroelectric material, preferably comprising Barium Strontium Titanate (BST).

Abstract: An antenna device and system design form a modular common antenna surface having various surface portions for transmission and reception as well as integrated transmission and reception within the same common antenna surface, the various surface portions either forming passive or active arrays for transmission or reception. Additionally superimposed surface portions of the modular common antenna surface constitute individual transmit and receive array portions, respectively, sharing the total aperture, the modular common antenna surface producing at least one polarization plane for transmission and generally two orthogonal polarization planes for reception to achieve polarization diversity for the reception.

Abstract: The present invention relates to antennas. One of the problems which arises during the operation of a linear array antenna with electrical downtilt is that cross-polar radiation currents are generated. These cross-polar radiation currents, if at the same frequency as the operating band of the antenna, interfere with the required gain of the antenna. The present invention provides a solution to cross-polar radiation currents with an antenna assembly comprising first and second apertured ground planes with an antenna probe feed network printed upon a dielectric substrate supported therebetween, the array of radiating elements having different phase input feeds, wherein an outwardly extending ground plane flange extends from one of the apertured ground planes. There is also provided a method of receiving and transmitting signals by means of a layered antenna of this construction.

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: A phased array includes a first plurality of radiators having a first polarization and a second plurality of radiators having a second polarization, different from said first polarization. The phased array is constructed such that radiating patterns of the first and second plurality of radiators are congruent. The radiators are constructed so that they radiating apertures thereof can occupy virtually the same space, i.e., the spacing of the radiating elements is less than a wavelength. Other features provided allow this compactness to be achieved. Impedance matching features are integrated into the radiators themselves. The elevation assemblies of the radiators are mated together, and then are coupled across to their respective azimuth assemblies. Two azimuth assemblies for either type of polarization may be provided when monopulse operation is required.

Abstract: Antenna devices, including a pair and larger arrays of radiators, wherein each pair is to be connected to a first transmission line having a first characteristic impedance Z1. Each pair includes at least first and second radiating elements (1, 2) and first and second impedance transformers (3, 4) for the first and second radiating elements. One side of each transformer is connected to the respective element. The other sides are inter-connected by a second transmission line (8) to which their impedances are matched. The second transmission line has a resistive first impedance R1 equal to twice the first characteristic impedance Z1. The first transmission line is to be connected to the second transmission line at a selected one of many possible contact points (9). The selected contact point then determines a signal phase difference between said first and second radiating elements.

Abstract: A broadband partial fan cone direction finding antenna and array disclosed. The antenna includes a radiator having a partial cone shape. The radiator substantially occupies a spatial area defined by a portion of a cone and the cone is defined by a cone axis, a cone height, and a cone angle. The cone has a base and an apex, and the portion of the cone is defined by a cone sweep angle. The cone sweep angle is determined as the angle subtended by a projection of the portion of the cone projected onto a plane that is perpendicular to the cone axis. The cone sweep angle is less than 360.degree. so that the portion of the cone is bounded on its sides by edges which extend radially from the apex of the cone outward to the base of the cone.

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: A multilayer dielectric line circuit in which a dielectric line circuit has a multilayer structure so as to be easily formed with a small overall size. In one form of the invention, first and second dielectric strips and first and second dielectric resonators are provided between respective adjacent pairs of conductor plates. The first dielectric strip and the first dielectric resonator, the first and second dielectric resonators, and the second dielectric resonator and the second dielectric strip are each coupled electrically or magnetically so as to couple the respective dielectric strips in the different layers.

Abstract: A communication system for transferring data through the air over a relatively short fixed distance comprising a transmitting antenna which comprises a leaky coaxial cable for radiating electromagnetic energy modulated with data to be transferred; and a plurality of non-linear fixed beam array antennas for receiving the modulated electromagnetic energy from the leaky coaxial cable. The plurality of fixed beam array antennas are juxtaposed with the transmitting antenna such that the transmitting antenna extends at least partially through the near-field regions of the plurality of fixed beam array antennas. The communication system also comprises a selection means which determines which radio frequency output from the plurality of non-linear fixed beam array antennas exhibits the greatest radio frequency power and outputs that particular radio frequency output to a receiver.

Abstract: A reconfigurable multiple beam array antenna for transmitting beams includes a reflector and radiating elements for feeding beam signals to the reflector. The array antenna includes a reconfigurable beam forming network having a plurality of dividers, a plurality of adjustable phase shifter and attenuator pairs, and a plurality of combiners to form beam signals from beam signals input to the beam forming network. A first hybrid matrix formed by an association of couplers is connected to the beam forming network for receiving the beam signals. Amplifiers receive and amplify the beam signals from the first hybrid matrix. A second hybrid matrix formed by an association of couplers is connected to the amplifiers for receiving the beam signals. The second hybrid matrix provides the amplified beam signals to the radiating elements for the reflector to transmit beams.

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.

Abstract: A polarization diversity device for reducing a fading effect. The polarization diversity device for reducing a fading effect, which has a microstrip disk type of antenna for outputting a signal received from a first position, in the form of a field dipole polarized in a direction of X, and outputting a signal received from a second position perpendicular to the first position, in the form of a field dipole polarized in a direction of Y, a phase shifter for phase-shifting the signal received from the second position, thereby to set the signal having the most appropriate value to a fading environment of a corresponding channel, and a combiner for combining the signal received from the first position, with the signal outputted from the phase shifter.

Abstract: A phased-array antenna structure is provided that includes an antenna waveguide structure with a plurality of waveguides. The antenna waveguide structure propagates the received or transmitted electromagnetic (EM) signals within the plurality of waveguides to a corresponding active array module. Each active array module amplifies and adjusts the phase of a received or transmitted EM signal. The active array modules are coupled to an interconnect structure that provides EM signal propagation paths, as well as power and digital signal paths, to and from the active array modules. A plate is coupled to the interconnect structure and the antenna waveguide structure to support the antenna waveguide structure, the electronic modules, and the interconnect structure, thereby forming a rigid unit and keeping the electronic modules in alignment with their corresponding waveguides in the antenna waveguide structure.

Abstract: An electronic scan antenna for generating an electrically scanned RF beam in response to an incident RF beam having at least one operating frequency band associated therewith includes a ground plane for reflecting the incident RF beam and a phasing arrangement of plasma structures operatively coupled to the ground plane. Each plasma structure includes gas containing areas which are reflective at the operating frequency range, when ionized, forming ionized plasma areas. Each ionized plasma area is disposed a first distance from the ground plane, a second distance from adjacent ionized plasma areas and each plasma ionized plasma area has a particular size associated therewith. In this manner, each ionized plasma area, in cooperation with the ground plane, provides a portion of a composite RF beam which has a phase shift associated therewith.

Abstract: Multi-beam antenna feed networks employ more aperture ports (e.g., ports I, II, III, IV and V) than beam ports (e.g., ports A, B, C and D) to achieve low sidelobe lossless operation, particularly for cellular communications. With five aperture ports, signal value outputs at the aperture ports represent orthogonal outputs having phase gradients effective to provide a four beam radiation pattern. The feed arrangement includes directional couplers (e.g., C11, C21) and phase shifters (e.g., P22, P23) intercoupled between the beam ports and aperture ports to provide the desired orthogonal aperture excitation. An example of specific directional coupler and phase shifter circuit values for a matrix network for a four beam port to five aperture port feed network configuration is provided.

Abstract: Apparatus and method for providing an antenna feed (10) operative at different microwave frequency bands employ a circular waveguide (14) interconnecting an orthomode transducer (20) to a feed horn (16) thereby providing a feed (10) suitable for illuminating the reflector (54) of an antenna (12). The orthomode transducer provides for a coupling of waves in the first frequency band with both vertical and horizontally polarized waves. Included within the feed is a coupler assembly (26) of waves of the second frequency band operative via a sidewall of the circular waveguide. The coupler assembly includes plural identical coupling sections (28) each having a rectangular waveguide section contiguous and parallel to the circular waveguide with a row of apertures for coupling power into and out of the circular waveguide. Pairs of the coupling sections are disposed in orthogonal planes so as to introduce two linearly polarized waves which are perpendicular to each other.

Abstract: A phased array (20) and method for constructing the same are disclosed. The phased array (20) includes a superstructure (22) with cavities (40) therein. A cover plate (28) is mounted to the superstructure (22) and cooperates with the cavities (40) to form cavity style filters therebetween and to form a box-beam type superstructure. Ideally, the superstructure (22) is self supporting. Electronic modules (32) and amplifiers (33) are mounted to the superstructure (22). The method includes machining a block of material to form a webbed superstructure with cavities (40) therein. A cover plate (28) is mounted to the superstructure (22) over the cavities (40) to form cavity style filters. Amplifiers (32) and antenna elements (30) are then affixed to the superstructure (22) and cover plate (28). Ideally, the cover plate (28) is affixed to the superstructure (22) using an electrically conductive adhesive.

Abstract: Multiple shaped-beam or scanned beams reflector or lens antenna configured so as to have the radiating elements outside the focal plane (imaging) with improved characteristics in terms of gain and coverage area. Said antenna (FIG. 1) essentially consists of a reflector or a lens (1), a certain number of radiators (3) positioned outside the focal plane, a Beam Forming Network (BFN). It classifies in the technical field of multiple shaped-beam antennae and is applicable to radars, telecommunications in general and to space telecommunications in particular. Its most significant advantage consists in its use as transmitter antenna since in it the electric performance/complexity ratio is improved.

Abstract: Planar microwave antennas are described of the type formed from a plurality of moulded planar layers. A first layer defines horn elements and two underlying layers define waveguide channels communicating with the horn elements. The waveguide channels are formed at the interface between layers by aligned channels in the abutting surfaces. The surfaces of at least the horns and waveguide channels are metallised, and the layers may be secured together by rib welding.

Abstract: A device for distributing a microwave signal in an array antenna to a number of radiating elements includes a main branching point at which the microwave signal is distributed to a first and a second antenna section. Each antenna section has a number of branching points connected in series, each of which distributes the microwave signal supplied to the branching point between a waveguide, connected to the branching point, and the next branching point connected in series. A number of parallel branches are connected to the waveguide. These parallel branches distribute the microwave signal supplied through the waveguide between the radiating elements.

Abstract: An improved BST dielectric powder is created used a sol-gel procedure. Addition of graphite to the powder, followed by a firing of the mixture results in a highly porous BST substrate, with the included graphite being burned off. By adjustment of the amount of added graphite, the porosity of the BST substrate is widely adjustable and enables achievement of a low bulk dielectric constant. A low dielectric filler is added to the fired substrate so as to provide a composite substrate with physical rigidity. Conductive layers are then adhered to the composite substrate to enable a tuning of the dielectric constant in accordance with applied DC voltage potentials. Antenna and other applications of the improved composite BST substrate are described.

Abstract: A multiband phased-array antenna interleaves tapered-element radiators with waveguide radiator to facilitate the simultaneous radiation of antenna beams across a bandwidth in excess of two octaves. The launch ends of the waveguide radiators collectively define a ground plane. The tapered-element radiators have pairs of tapered wings which are extended past the ground plane by a distance which is selected to establish a predetermined tapered wing radiation impedance. The radiators of each type are spaced apart by a span which insures that they will not generate grating lobes at the highest frequency which they respectively radiate.

Abstract: There is provided an improved planar antenna, for use in satellite communication, capable of providing higher aperture efficiency, improved circular polarization and increased production tolerability. The antenna comprises a waveguide and an array of M.times.N helical antenna elements, wherein M and N are integers.

Abstract: A phased array antenna (10A, 10B, 10C) is constructed of an array of radiators (24), each of which has a radiating aperture, a first port (26) and a second port (26). The first port introduces a first radiation with a first polarization, and the second port introduces a second radiation with a second polarization which is orthogonal to the first polarization. Individual transmitting amplifiers, in the case of a transmitting array, or individual receiving amplifiers (16A), in the case of a receiving array, are connected to the ports of each of the radiators. The amplifiers associated with the first ports of the respective radiators are connected, in turn, to phase shifters (18A) and attenuators (20A) which constitute a first beamformer for forming a set of one or more beams of radiation.

Abstract: A microstrip antenna device having a dielectric layer, a conductive patch of a chosen shape on one side of the layer and, on the other side of the layer, a conductive plate forming a ground plane; and, a feed circuit comprising at least one microstrip line connected to the conductive patch and implanted in the dielectric layer in the same plane as the conductive patch. The thickness of the dielectric layer opposite the microstrip line is greater than the thickness opposite the periphery of the microstrip line. Further, the thickness of the dielectric layer opposite the conductive patch is greater than the thickness opposite the microstrip line, and also greater than the thickness opposite the periphery of the conductive patch.

Abstract: A unitary array of efficient directional corrugated feed horns, each having a desired corrugated horn cross-section within close tolerances, as well as accurate positioning and orientation relative to each other. The unitary array structure is comprised of a plurality of thin platelets which are laminated together in a selected sequence. The unitary array design provides a mechanical structure to support millimeter and sub-millimeter wavelength electronic devices for reception or transmission of electromagnetic energy and cooling fluid circulation channels within the array to remove unwanted heat generated by the attached electronic devices. The design of the present invention affords a relatively lightweight structure through removal of unneeded materials by forming cavities within the structure while leaving sufficient material for the bonding of the platelet assembly.

Abstract: An antenna having antenna modules for an extremely wideband active monopulse phased array system, the modules including a housing provided with four radiators of the rectangular open-ended waveguide type and with an electric circuit. With the antenna modules being suitably stacked, the radiators constitute a substantially continuous antenna surface, the radiators being positioned at the points of intersection of a system of equilateral triangles which make up the antenna surface. After preamplification, phase shift and down-conversion to an intermediate frequency, received signals from a large number of antenna modules are combined to yield a sum beam, an azimuth difference beam and an elevation difference beam.

Abstract: A linear conformal array antenna consisting of double-ridged waveguide elements which are all tapered in the E-plane or the H-plane. The array of waveguide elements is fed by a Gent lens whose amplitude and phase characteristics can be adjusted to cause the waveguide element array to produce a desired radiation pattern. The linear array antenna, which has been tapered in the E-plane, can be operated to scan an electromagnetic endfire beam in one predetermined direction with a maximum scan loss of 3 dB. The array of waveguide elements can be substantially conformal with the fuselage of an airborne craft carrying the linear array antenna, thereby reducing aerodynamic drag and radar cross section. The linear array antenna has a bandwidth that is greater than an octave wide.

Abstract: A phased array antenna includes an array of phase shifters, each shifter being operable for shifting the phase of RF energy passing therethrough. Each shifter includes a quantity of ferroelectric material disposed throughout a region. RF energy propagating from a source passes through the material. A thin conductive electrode is disposed in the center of the material, the electrode having a bias voltage imposed thereon. Such voltage creates an electric field across the material, which for a uniaxial ferroelectric orients the optic axis of the material in a direction which is both normal to the direction of propagation of the RF energy and parallel to the polarization direction of the RF energy. The electric field changes the wave propagation constant (i.e., for a uniaxial ferroelectric, the extraordinary wave refractive index, n.sub.e), producing a varying path length of the RF energy in the material, resulting in a controllable alteration of the phase of the RF energy.

Abstract: A 90.degree. coupling circuit cascaded with a pair of hybrid mode latchable phase shifters provides polarization agility for an RF radiator module of the type typically used in a phased array. For example, such radiator modules typically may utilize an active microwave integrated circuit (MIC), a monolithic microwave integrated circuit (MMIC) or a passive reciprocal hybrid mode element (RHYME) circuit. These circuits are arranged to provide duplex RF transmit/receive functions with controllable phase shifts at each radiator site in a phased array. By appropriately setting the two controllable phase shifters to different combinations of phase shifts (e.g., 0.degree. and/or 90.degree.) to a dual orthogonal mode radiator, different spatial polarizations for RF radiator transmit/receive functions can be defined. The radiator itself may include a square or circular waveguide including, in some cases, a reciprocal dielectric quarter-wave plate and a non-reciprocal ferrite quarter-wave plate.

Abstract: A low cost, light weight, high performance phase shifter mounting structure which allows high density packaging of phase control modules for phased array antennas. The mounting structure is a bimetallic sandwich design in the shape of an I-beam having a top flange for mating to radiating elements, a bottom flange for mating to a feed network, and a center web for mounting phase control modules. The I-beam is formed from a single piece of laminated stock comprising an outer layer of aluminum and a core layer of titanium forming an anisotropic thermal expansion composite material. The titanium center web matches the coefficient of thermal expansion of the typical ferrite, MIC, or MMIC phase shifter and driver circuits. The aluminum flange material allows easy machining of microwave transitions at each end of the I-beam and matches the expansion of typical radiating element structure and feed networks.

Abstract: A phased array antenna structure has a distribution network, and a composite of feed, module, and antenna honeycomb structures. The distribution network distributes or collects electromagnetic (EM) energy. The feed honeycomb structure is positioned adjacent the distribution network and connected to receive the EM energy from the distribution network or to distribute EM energy to the distribution network. The module honeycomb structure is positioned adjacent the feed honeycomb structure so as to receive EM energy from the feed honeycomb structure or to transmit EM energy to the feed honeycomb structure. The antenna honeycomb structure is positioned adjacent the module honeycomb structure on a side opposite the feed honeycomb structure so as to receive EM energy from the module honeycomb structure or to transmit EM energy to the module honeycomb structure. Each of the feed, module and antenna honeycomb structures have a plurality of aligned waveguides for transmitting EM energy therealong.

Abstract: A waveguide feeding array antenna is provided to be capable of separating and taking up each of the polarization components of the horizontal and vertical polarized waves received concurrently at an opening of each of a plurality of waveguides arranged to form a network, by means of a taking-up equipment disposed in the waveguide circuit. The both polarization components can be made thereby to be effectively separated from and composed with each other while realizing the simplification and economization of the waveguide network.

Abstract: A phased array waveguide antenna having a plurality of longitudinally extending parallel waveguides arranged in rows and columns, and electrically controlled phase shifter strips disposed in longitudinally extending slots centrally located in respective columns of waveguides. The electrically controlled phase shifter strips include conductive patches that are selectively conductively connected together by microwave diodes to provide for variable susceptances.

Abstract: RF manifolding for a radar antenna which allows tight spacing of Phase Control Modules (PCMs) is disclosed. The manifolding consists of ridged branch manifold waveguides to which ridged cross waveguide sections are installed. Each branch manifold waveguide of the present invention has ridges on one broad wall, coupling slots on another broad wall, and a plurality of cross waveguides connected on the side having the coupling slots. The cross waveguides are likewise provided with ridges on one broad wall, which are oriented at right angles to the ridges of the branch manifold waveguide, and have coupling slots on the opposite broad wall which correspond to the coupling slots of the branch manifold waveguide. The PCMs are mounted on the end of each cross waveguide, parallel to the ridges thereof.

Abstract: A planar microwave antenna having a resonant back structure (22) constituting a common back plane cavity for an array (20, 27) of resonant slots (21). The back structure (22) comprises a sheet of metal having an arrangement of mechanically pressed projections forming lands (23). The projections extend towards the regions between the slots (21) of the array (20) and are so shaped and positioned that the lands (23) do not intrude into areas of the back plane exposed by the slots (21). The lands (23) provide a rigid support for the slot array (20) and reduce the dimensional tolerance problems encountered in antennas having a single flat back plate. Further, the projections reduce the number of possible degenerate waveguide modes to give an improved antenna performance. The provision of a common back cavity also enables a closer slot spacing than can be achieved when using individual cavities for each pair of slots.

Abstract: A flat phased array antenna for reception of circularly polarized high frequency signals. The flat antenna array consists of a number of subarrays arranged in a matrix. In turn, each of the subarrays consist of individual antenna elements arranged in a matrix. In one embodiment, each subarray consists of four layers stacked one on top of the other. The top layer defines an array of miniature reception horns. Secured to the top layer is a second layer which constitutes the short-circuit plate of the antenna array. The short-circuit plate contains a plurality of through holes disposed about the surface of the circuit plate to permit passage of pairs of cylindrically shaped probes. The two remaining layers constitute the first power dividing layer and the second power dividing layer, respectively. Each of the layers includes transmission line waveguides.

Abstract: A planar antenna of the kind comprising feed lines disposed in a flat circuit and cooperating by hyperfrequency coupling with a metal ground plane plate pierced by apertures has the feed lines presenting a termination juxtaposed with each aperture. A lower ground plane plate is disposed at a distance of approximately a quarter wavelength from the apertured metal plate. The apertured metal plate comprises a metal coating deposited on a dielectric substrate. The feed line comprise central conductors disposed in channels which open into the apertures. The array of apertures, channels and conductors can be produced on the dielectric substate by single face printed circuit techniques. The antenna may be used for the reception of direct broadcasts from satellites.

Abstract: The I.F.F. sum and difference channels are obtained by means of the reflector of the radar, illuminated by primary radiating elements associated with the horn of the primary source of the radar. Furthermore, the signals of the I.F.F. sum and difference channels are suitably mixed to obtain a reduction in the level of the cross-polarized signals.

Abstract: A device for exciting a waveguide with circular polarization from a plane antenna, said waveguide (10) being a rectilinear hollow waveguide closed at one of its ends (12), said antenna being excited by at least two coaxial ports (13, 14) fed in phase quadrature by a circuit including a hybrid coupler (15), and being constituted by a radiating plane metal pattern (11) disposed on the surface of an insulating substrate (18) closing the waveguide (10) perpendicularly to its axis of symmetry.