Abstract: An antenna for an integrated circuit card includes a conductive track (2) forming at least one turn and having ends (3) comprising conductive layers forming connection terminals (4), the connection terminals (4) being perforated. An integrated circuit card is provided that includes such an antenna.

Abstract: A tapered slot antenna is provided including a substrate and a metal layer which is disposed on the substrate and removed in a region to form a tapered slot portion having a closed narrow end and extending outward toward a relatively wider end that is open. The tapered slot antenna is further provided with a corrugated structure including a plurality of slits formed periodically positioned in opposing outer edge portions of the metal layer parallel to the direction of the radiation by removing rectangular portions of the metal layer, having a sit depth ranging from 0.04 wavelengths to 0.12 wavelengths. With the structure, an electric field component can adequately be generated to thereby reduce the cross-polarized D-plane component and the electric field intensity at the substrate edge portions as well.

Abstract: A polyrod antenna fed at an end by a flared notch antenna. The space required to feed the polyrod is reduced, and a broader operating bandwidth is achieved. Gain of the antenna can be increased by increasing the polyrod length. A number of the polyrod antennas can be packed together in an array configuration.

Abstract: A dual beam monopulse antenna system includes a flat plate antenna (10). The antenna (10) comprises a plurality of slotted waveguides (20) which transmit radiation through slots (28). The antenna is divided into quadrants (12, 14, 16, 18) for monopulse operation. Each of the quadrants is provided with primary and secondary feed lines which are connected through directional couplers (42-136) to connecting lines (146-192) to the slotted waveguides (20). The primary feed lines (26, 28, 30, 32) are connected to a primary monopulse comparator network and the secondary feed lines (34, 36, 38, 40) are connected to a secondary monopulse comparator network. The summation terminals of the monopulse comparator networks are connected to a switch network (322). The azimuth differential terminals of the monopulse comparator networks are connected to a switch network (332). The elevation differential terminals of the monopulse comparator networks are connected to a switch network (342).

Abstract: A digital signal, beam radiation antenna consisting of a cylindrical mast having an inner tubular conductor and an outer tubular conductor, and means for exciting said inner conductor to establish a traveling wave internal to said antenna. Moreover, there are spaced slots in said outer conductor defining an illumination aperture coupled to the inner conductor and for radiating the beam from the antenna. This establishes the illumination along the aperture so as to produce a high beam tilt of the order of 0.6-3.5 degrees from the horizontal for the beam radiation; further, for varying the phase from layer to layer, such that there are substantially no null variations in the elevation pattern of the beam.

Abstract: The present invention relates to an antenna unit (101) capable of operating in a satellite communication mode. The antenna unit (101) comprises interleaved circular patches for transmitting (102) and receiving (103) radio signals periodical arranged in a first and a second layer. The patches for transmitting (102) in the first layer are arranged in a first lattice (104) and the patches for receiving (103) in the second layer are arranged in a second lattice (105). The first lattice (104) is interleaved with the second lattice (105). Every other patch for transmitting (102) in the first layer has a corresponding patch for receiving (103) in the second layer, where each of the patches for receiving (103) are arranged in such a way that a center axis of the patches for receiving (103) coincide with a center axis of the corresponding patch for transmitting (102).

Abstract: A tapered slot antenna includes a dielectric sheet, a conductor layer laminated on said dielectric sheet, in which conductor layer a tapered slot pattern is formed as a result of a slot width of a slotline being widened gradually, and corrugated structures provided at two sides of said conductor layer, parallel to a direction in which an electromagnetic wave is radiated from said antenna. The shape of said antenna is axially asymmetrical.

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: In order to offer a tunable slot antenna capable of varying an impedance matching center frequency thereof, there is provided a coaxial resonant slot antenna for supplying RF power to a strip conductor placed in a flat conductive cubic with a slot formed in its upper surface and electrically insulated from the flat conductive cubic, wherein a variable capacitor is electrically connected between one point lying in the neighborhood thereof including an end far from a RF power connection point on the strip conductor and a side wall of the flat conductive cubic, and a d.c. voltage to be applied across the variable capacitor is supplied to the connection point.

Abstract: A geodesic slotted cylindrical (GSC) antenna having a shaped elevation pattern and a narrow or shaped azimuth beam that can be scanned 360.degree. in the azimuth plane. The azimuth radiation pattern of the GSC antenna can be reconfigured through the use of interchangeable beam forming feed networks. The GSC antenna comprises a parallel plate waveguide formed by spaced-apart inner and outer cylinders constructed from conductive material. Radiation occurs from a stack of circumferential slots in the outer cylinder. By varying the slot spacing with the azimuth angle, the elevation pattern can be altered as a function of the azimuth angle. The GSC antenna can be excited by a number of equally spaced probes on a circle at the base of the cylinders. The feed radius is typically smaller than the outer cylinder's radius to minimize the number of active components and to minimize the number of spurious ray paths that can wrap around inside the cylinder's parallel plate region.

Abstract: A ferrite scanning line source is formed of a ferrite toroid and one or more dielectric slabs mounted to a side of the toroid. A signal propagating through the waveguide is phase shifted by the magnetization of the toroid. The further down the toroid the signal propagates the greater the phase shift that is applied to the signal. Radiators or coupling ports are formed by slots cut in a wall of the waveguide. The phase of the signal radiating from each slot in the line source is shifted from the signals emanating from the preceding and following slot in the line source. By properly locating the slots along the line source, a composite beam formed by the energy radiating from each slot may be titled (scanned) to a desired direction. In addition, the amount of phase shift applied to the signal by the waveguide depends on the magnetic state of the phase shifter.

Abstract: A slot antenna is disclosed for use in RF broadcasting. The antenna includes an elongated longitudinally extending hollow mast surrounding a longitudinal axis. An array of longitudinally spaced slots are formed in the mast for radiating electromagnetic energy therefrom. A coupler bar is associated with each slot. Each coupler bar is located within the mast between the ends of the associated slot for coupling electromagnetic energy from within the mast and developing with the slot a slot-coupler reactance. Tuning means is associated with each slot. Each tuning means is longitudinally spaced from the associated slot. Each tuning means extends inwardly from the mast toward the longitudinal axis for tuning the antenna to reduce the slot-coupler reactance.

Abstract: A slot antenna having an elongated tube with a slot extending along the longitudinal axis of the tube provides an antenna structure for a wide-band communications antenna. The configuration of the tube and slot provide an antenna with an input impedance of about 50 ohms. A plurality of feed points are spaced along the slot for radiating and receiving wideband RF signals. When oriented vertically with respect to the earth, the antenna radiates and receives horizontally polarized signals with a high rejection of vertically polarized signals. When oriented horizontally with respect to the earth, the antenna radiates and receives vertically polarized signals with a high rejection of horizontally polarized signals. The antenna tube is coupled to a rectangular ground plane extending substantially the length of the antenna tube.

Abstract: A scanning array antenna employs a solid rotating core having an anisotropic refractive index within an apertured waveguide that emits radiation in response to an input beam propagating through the waveguide. Rotating the core changes its refractive index relative to the input beam, causing the radiated beams to undergo an angular scanning. The solid rotating waveguide core can be formed from a dispersion of aligned elongate conductive members in an isotropic dielectric, from a liquid crystal medium, or from a dispersion of aligned elongate conductive members in a liquid crystal medium. The antenna is operable in reciprocal transmission and reception modes.

Abstract: A slotted waveguide array antenna includes a plurality of waveguide elements extending in a parallel side-by-side relation, each having a radiating side including a broad wall formed with a plurality of slots, and an asymmetric ridge. The slots are slanted to the longitudinal axis of the antenna in alternating directions and are spaced .lambda.g/2 apart such as to offset phase reversal between each pair of adjacent slots.

Abstract: An antenna apparatus comprises a dielectric substrate, an earth conductor mounted on one surface of the substrate and forming a microstrip transmission line, an upper conductor mounted on the other surface of the substrate and forming a microstrip transmission line, an antenna element formed integrally with the microstrip transmission lines, and a delayed wave opening situated in the earth conductor in confronting relationship with the upper conductor.

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: A dual polarized flat plate antenna wherein a deliberate unbalance of phase and/or amplitude is introduced into a feed arrangement for one of the polarizations such that interactive coupling between colocated elements associated with the respective polarizations causes the beamwidth and/or shape of the radiation pattern for the other polarization to be controlled.

Abstract: The present invention relates to an improvement of an antenna apparatus for a transceiver that is capable of obtaining a stable operation of an antenna without being affected by different sizes of wrist bands or by a durability of a metal clasp. An antenna unit (14) is comprised of a strip shaped conductive plate (13), whose slot (13a) is formed in the longitudinal direction of wrist band (12), which is connected to a casing (11) of the wrist type transceiver (10). One conductive section of slot (13a) of the conductive plate (13) provides a feeding point (131) in order to supply a positive potential. The other conductive section (130b) provides a second feeding point (132) in order to fix the other conductive section (130b) to the ground potential. A capacitance element (19) is attached between one conductive section (130a) and the other conductive section (130b) of the conductive plate (13).

Abstract: An apparatus is disclosed for providing a radiating element having an electrical reflective phase shifter for reflecting electromagnetic energy received from an electromagnetic energy source including a dielectric substrate having a top surface, a conductive layer having a channel-like opening in its top surface and disposed on the top surface of the dielectric substrate, at least one electrostatic switch spans the channel-like opening and a means for selectively actuating the electrostatic switch to reflect the electrostatic energy. The electrostatically actuated mechanical switch utilizes a cantilever element fabricated by solid-state microfabrication techniques. The electrical reflective phase shifter can be grouped into a phase shifting reflect array for beam steering an electromagnetic energy from an electromagnetic energy source.

Abstract: A metal flared notch radiator with separate and isolated transmit and receive ports for an active array. A 4-port circulator is integrated into the transition of the radiator so that the integrated device has have a separate transmit port, a separate receive port, and a separate termination port to provide isolation between the transmit and receive.

Abstract: A non-linear solid state conductor placed across a resonant aperture formed in a surface reflective of electromagnetic energy becomes conductive under the influence of a microwave field above a threshhold energy level of intensity to render the resonant aperture fully reflecting for the bandwidth of frequencies associated with the geometry of the resonant aperture.

Abstract: A constant gain sector beam array is obtained by applying equal amplitude, equal phase excitations to a sector array characterized by a curved array geometry. In a simple form, the curve is the arc of a portion of a circle. The radiation pattern can be further enhanced by using a more complex curvature geometry, and by minor adjustments to the amplitudes in the slots. Other forms of shaped beams, such as a cosecant squared antenna pattern, may be obtained by appropriately shaping the curvature geometry.

Abstract: A multimode low-profile avionics antenna is disclosed for use in Automatic Direction Finder (ADF) systems. The low profile antenna generates a steerable cardioid radiation pattern having a minimum bandwidth of 30% and an unusual degree of independence from mutual coupling and coupling to ground-plane currents. The antenna includes two resonant cavity-backed slot antennas. The upper cavity, which backs a directional crossed-slot antenna, is the larger of the two cavities. The shallow lower cavity is actually a short-circuited radial transmission line employing a stepped inner radius and band-switching to extend the operating bandwidth to the required 30%. The crossed-slot antenna elements are configured orthogonally and the slot ends are folded over the side of the cylindrical cavity to minimize the resonant cavity diameter for the requisite slot length.

Abstract: An antenna system having first and second arrays of radiating members, first and second sets of corresponding bifurcated members and two pairs of feed members. The radiating members of the first and second arrays each have a near end and a far end and a linear portion therebetween with radiating slots formed therein. The linear portions of the radiating members are interleaved in a planar spaced parallel relationship. Each bifurcated member has a unitary portion and a bifurcated portion with the bifurcated portion having a pair of coupling ends. Each bifurcated member is coupled at its unitary portion to the near end of a different radiating member of its corresponding array and also coupled at its coupling ends to a different feed member of its corresponding pair of feed members. The antenna system further includes a monopulse comparator coupled to the input ends of the first and second pairs of feed members for operation as an amplitude comparison monopulse antenna.

Abstract: A printed circuit cavity-backed crossed-slotted conductive element having two legs of each slot coupled by stripline feeders to a radio communications device. The feeders supply the radio frequency signal with a 180 degree phase shift in order to cancel cross-coupling from one leg to another around the intersection. The conductive element and the stripline feeders are mounted on separate substrates which are attached together with other elements to provide shielding and mechanical protection. The crossed-slot design reduces space and structure required for a mobile application while achieving good performance. When mounted in an array, the crossed slot antennas may be directionally tuned to a specific satellite/frequency/direction via pin diode phase shifters.

Abstract: Disclosed is a circular waveguide in which a slots are formed which are shaped and disposed such that they interrupt either the right hand or left hand circulating mode (RC and LC respectively) residing in the waveguide. Locating the slots in the waveguide wall is accomplished in accordance with the theory that for TE modes in circular waveguide with circumferential variation of e.sup..+-.jm.phi., current flow lines are produced that are helical. The slots are located so as to interrupt the helical current of the desired mode. In one embodiment, an ortho-polarization mode transducer and a circular polarizer are used to feed the slotted waveguide. By control of the amplitude and phase of the energy propagating in the waveguide, azimuthal pattern control can be effected. By dielectric loading the waveguide to make .lambda.g in the loaded waveguide equal to .lambda.-free space, endfire radiation can be achieved.

Abstract: A dipole exciter for an antenna for the transmission of electromagnetic waves which is arranged on the free end of a rigid co-axial line is described. The dipole consists of two flat metal pieces (10, 11) which are arranged on the outer conductor (6) of the line and the main dimension of which extends at right angles to the axis of said line.

Abstract: Disclosed is a circular waveguide in which a slots are formed which are shaped and disposed such that they interrupt either the right hand or left hand circulating mode (RC and LC respectively) residing in the waveguide. Locating the slots in the waveguide wall is accomplished in accordance with the theory that for TE modes in circular waveguide with circumferential variation of e.sup..+-.jm.phi., current flow lines are produced that are helical. The slots are located so as to interrupt the helical current of the desired mode. In one embodiment, an ortho-polarization mode transducer and a circular polarizer are used to feed the slotted waveguide. By control of the amplitude and phase of the energy propagating in the waveguide, aximuthal pattern control can be effected. By dielectric loading the waveguide to make .lambda..sub.g in the loaded waveguide equal to .lambda.-free space, endfire radiation can be achieved.

Abstract: A microwave phase shifter comprise a dielectric waveguide having a flat side and a moving conductor plane member substantially parallel to the waveguide side. Piezoelectric means are provided to move the plane member with respect to the waveguide side between a portion relatively remote from the waveguide side and an other position substantially in contact with the waveguide side. The piezoelectric means consists preferably of a stack of piezoelectric members supplied by a variable d.c. power source. Owing to the piezoelectric means for moving the conductor plane member, a variable phase shift is continuously adjusted. Such a phase shifter can be as an antenna network when the dielectric waveguide contains groups of radiator perturbations, such as conductor strips, respectively controlled by one or several piezoelectric means carrying conductor plates facing waveguide portions including the perturbations groups.

Abstract: A probe-fed slot antenna is provided having an inner conductor, a cylindrical outer conductor coaxial with the inner conductor, and a plurality of slots in the outer conductor. A plurality of probes extend from the cylindrical outer conductor into the interior, each probe adjacent to one of the slots. A coupling ring is mounted coaxially between the outer and inner conductors to allow efficient transfer of RF energy to and from the slots.

Abstract: A flat microwave antenna comprising a network of emitting or receiving elements constructed by means of the printed circuit technique on a dielectric support. The elements are arranged on a series of radii (A to H) and are relatively equidistant on each of these radii. In the simplest construction, the radii are equiangularly spaced and the number of elements per radius is equal to 2.sup.n, n being a positive integer proportional to the length of each radial segment.

Abstract: An electronically scanned array antenna useful for millimeter wavelength energy is disclosed. The antenna comprises a fully ferrite loaded square or round waveguide having radiating apertures spaced along part of its length. Rf energy is circularly polarized in the waveguide. The phase velocity of the wave is controlled by applying a longitudinal magnetic field to the ferrite to produce a controllable linear progressive phase of the energy radiated from the apertures to form a beam in the desired direction. The phase control is of a latching type using flux drive. The particular structure of the invention enables combining a plurality of branching array elements with a feed element to form an array capable of two dimension beam scanning.

Abstract: A modular integrated multi-element phased array antenna. The antenna is comprised of a supporting structure having a plurality of slotted, ridged waveguide radiator elements longitudinally extending therein and a single series ridged waveguide feed structure, having a first and second plurality of waveguide channels formed therein. The feed structure is supported by at least a portion of the supporting structure and receives microwave energy from a source and then couples the energy to the first plurality of waveguide channels. The antenna is further comprised of a multi-element phase shifter module positioned in juxtaposition with the feed structure for receiving the microwave energy from each of the first plurality of waveguide channels. The phase shifted energy is coupled from the phase shifter module to each of the second plurality of waveguide channels.

Abstract: A millimeter-wave electronic scan, phased array antenna in a slotted dielectric waveguide having a semi-insulating core and at least one semi-conducting epitaxial layer. A controller affixed to the epitaxial layer is used to apply a bias voltage thereby varying the conductivity of the layer and influencing wave propagation in the guide to effect beam scanning.

Abstract: Slow wave antenna including slow wave structure of a helical coiled conductor having linear capacitance and inductance distribution. Driving point impedance is changed by varying the ratio of the distributive capacitance to the distributed inductance. Tuning is changed by changing the capacitance between the distributive capacitance common and RF ground. Slow wave antenna structure includes a first embodiment having a slotted pipe with a helically wound conductor and a second embodiment includes a helically coiled element with a plane capacitance structure. In the slotted type of helically wound center conductor antenna, the antenna is tuned by changing the distance between the helix and the outside diameter of the pipe. The antenna is also tuned by changing the capacitance between the pipe and the ground of the RF system. In the helical element with a plane capacitance sheet antenna, tuning is accomplished by varying the spacing of the sheet and hence the capacitance between a conductive sheet and the helix.

Abstract: An antenna element for coupling circularly-polarized radiation to a feedline. The element includes a pair of superposed planar dielectric layers. An outer surface of each layer is covered with an electrically-conductive layer forming a ground plane and having a circular opening defining respective cavities. Orthogonally-crossed dipoles are disposed between the dielectric layers and adjacent the openings for coupling radiation to the feedline through striplines also disposed between the dielectric layers.

Abstract: An antenna drive arrangement for a very high frequency omnidirectional range (VOR) navigation system for aircraft. The antenna has two vertically arrayed antenna elements located above a ground plane, and reference and variable phase signals are distributed to each of the antenna elements in amplitude and phase relationship selected to produce a null in the H-component of the radiated field which is substantially tangential to a projection of the ground plane. The null is located in a region of the field disposed radially outwardly of the antenna array.

Abstract: A 360 degree scanning antenna is disclosed which includes a mechanism for anning the main beam of a cylindrical array in azimuth and over a limited angle in elevation in which a primary feedhorn illuminates a geodesic lens which in turn illuminates the cylindrical array structure. Energy is coupled from the parallel plate structure of the feedhorn assembly into the individual waveguides of the array via dielectric wedges extending from the waveguides.Scanning in elevation is accomplished by changing the transmitter frequency and in azimuth by rotating the primary feedhorn assembly.

Abstract: An antenna which is suitable for use in a very high frequency omni-directional range (VOR) navigation system for aircraft. The antenna is driven to radiate reference and variable phase signals which provide flight bearing information to an aircraft which enters the radiated field.The antenna comprises a cylindrical radiator which is formed with four orthogonally disposed longitudinally extending slots, and each slot is backed by a separate cavity which extends into the cylinder. Each cavity has an effective depth which is greater than the radial or, more usually, the diametral dimension of the cylinder, and all four cavities are configured so as to locate wholly within the cylinder.

Abstract: A line source antenna adapted for a light weight, compact phased array radar and consisting of a plurality of radiating slots periodically located in one side wall of a length of waveguide, having a single monolithic ferrite phase shifter in the form of a long continuous toroid extending the length of all of the slots.

Abstract: An array antenna having a plurality of radiating elements positioned in a planar configuration is divided into four separate quadrants. The array antenna is capable of being switched between two modes, a narrow pencil beam mode and a cosec.sup.2 .theta.cos.theta. mode, through the use of a single switch and a pair of phase shifters. In the pencil beam mode, the transmitted energy is symmetrically divided between the four quadrants of the antenna. By changing the switch to its second position the power is diverted to only the upper half of the antenna and a pair of phase shifters introduces a phase shift to the radiating elements along the lower half of the upper portion of the antenna. This causes an asymmetric radiation pattern from the antenna creating the cosec.sup.2 .theta.cos.theta. beam which is well suited for ground mapping.

Abstract: A specified pattern slotted waveguide antenna is achieved by controlling the amplitude and phase of each slot of the array. The amplitude and phase of each slot is controlled by selecting the proper spacing between slots, the proper offset or slanting of each slot from the long axis of a waveguide, and the proper termination of the waveguide. The selection technique considers both the incident and reflected voltages in the waveguide to produce the desired amplitude and phasing at each of the slots, and also provides a proper load to a generating signal at center frequency.

Abstract: A dual switch multimode array antenna capable of being switched between two modes through the use of two waveguide switches and a pair of phase shifters. The first mode produces a pencil beam with a monopulse capability and the two switches divide the transmit power equally between the four quadrants. A monopulse capability exists both in azimuth and elevation in this first mode. With the switches and phase shifters transitioned to the second position, illuminated power is directed to the two quadrants and the upper half of the antenna only. This produces the well known cosec.sup.2 .theta. cos.theta. beam in elevation. An azimuth monopulse capability is available in this mode.

Abstract: A multi-aperture array antenna provides a narrow beam width, low side lobe radiation pattern for an illuminating beam through the forward feed of a ladder-type feed structure. Alternatively, the rear feed of the ladder network is so electrically tapered as to provide three simultaneous low side lobe smaller apertures which can be independently directed via phase shifters to provide distinct received beams for interferometric phase comparison. A feed connected to one radiating element in each of the three apertures form a broad-beam pattern for side-lobe cancellation. A phase shifter is positioned adjacent to each radiation element to steer the beam and switch between antenna functions by precise control of the phase excitation to each port. The feed structure is connected in a ladder configuration forming a front feed and a rear feed.

Abstract: A doppler navigation antenna having automatic land-sea error correction through the utilization of two somewhat differently inclined lobe groups consisting of four lobes each, and employing a plane radiator group which comprises a plurality of individual radiators arranged in parallel rows. Each end of each radiator is fed by a pair of feed lines which extend transversely in the rows, the individual feed lines of each pair of feed lines having slightly different phase delay characteristics.

Abstract: An antenna array consists of one or more slotted-waveguide, linear subarrays. Slots for radiation are cut in both narrow walls of each such waveguides, and PIN diodes across the slots are selectably forward and backward biased to effectively open the slots along one waveguide narrow wall while the others are closed and, alternatively, vice verse.

Abstract: A reflectarray antenna includes a primary feed that radiates a primary wave to a plurality of radiators where the wave is absorbed. A portion of the absorbed wave is resolved into first and second mutually orthogonal components at first and second feed ports, respectively, of a radiator. The first component is transmitted with a designated phase shift via a transmission phase shifter to the second feed port. Correspondingly, the second component is transmitted with the designated phase shift via the phase shifter to the first feed port. After the components are transmitted to the feed ports, they are re-radiated by the radiator in polarization states orthogonal to the ones in which they were absorbed.

Abstract: A ridged rectangular launching waveguide and a ridged rectangular radiating waveguide have a common length-wise wall comprised of wall segments. A wave launched at the proximal end of the launching waveguide is coupled to the radiating waveguide through passageways between the segments. A cylindrical metal rod extends through a segment to the wavepaths of the waveguides. Additionally, the ridges of the waveguides have similar notches near the rod, the rod and the notches forming similar attenuators in the wavepaths. The passageways result in a formation of a pair of three-db, ninety-degree hybrids connected back-to-back through the attenuators. The hybrids and the attenuators couple a predetermined percentage of the energy of the wave to a radiating slot in a panel at the distal end of the radiating waveguide. The remainder of the wave energy is reflected by the attenuators and coupled by the hybrids through the radiating waveguide towards the proximal end thereof.

Abstract: A slotted-waveguide linear array in which a pattern of slots in a narrow wall of a first waveguide forms the aperture of the array. A second waveguide runs parallel to the first guide, the other narrow wall of the first waveguide being a common wall with the second waveguide. The pattern of coupling holes through this common wall couples energy between the waveguides.A feed arrangement, preferably including a 180.degree. hybrid, has two of its ports connected one each to the first and second waveguides, the difference port, when driven, providing 180.degree. phase feed of the two waveguides so that the presence of the second waveguide is substantially nil. Thus, a single beam is formed as if the second waveguide were not present. The feed also provides for excitation of the waveguides through a mutual hybrid in-phase relationship when the sum port of the hybrid is driven, in which case the beam is angularly separated from the original beam.