Abstract: A siamese feedhorn for a satellite receiving antenna capable of simultaneously receiving signals from satellites in different geostationary satellite positions. The siamese feedhorn preferably includes a first waveguide section mated with a second waveguide section. The first waveguide section is preferably positioned at the antenna's focal point to receive signals from within the antenna's beamwidth. The second waveguide section is positioned at an offset distance from the focal point to receive signals from a satellite in a different geostationary position.

Abstract: An outdoor satellite broadcast receiving converter including a waveguide into which a broadcast electric wave enters and in which the broadcast electric wave travels in an axial direction as a first linearly polarized wave and a second linearly polarized wave. A first probe is disposed at a predetermined position and extends perpendicular to the axial direction into the waveguide for detecting the first linearly polarized wave. A substrate is disposed in the waveguide approximately 1/4 wavelength from the first probe and arranged to extend across an open end of the waveguide. A first shorting terminal for reflecting the first linearly polarized wave is formed on a first side of the substrate, and a second probe for detecting the second linearly polarized wave is formed on an opposing second side of the substrate. A metallic case is connected over the open end of the waveguide such that the substrate is positioned between a closed bottom of the metallic case and the first probe.

Abstract: A feed system for an antenna has a set of inner and outer coaxial waveguides which apply, respectively, both higher and lower frequency radiations to a common radiating aperture provided by a horn and shroud which envelops radiating apertures of the individual feed waveguides. Each of the feed waveguides carries signals having a bandwidth of an octave. Lower frequency radiation to be transmitted by the outer coaxial feed waveguide is applied thereto by a set of four waveguides of a launcher which launches a wave with a desired propagation mode into the outer feed waveguide. Each of the launch waveguides is initially a rectangular double-ridged waveguide for increase bandwidth. The ridging is reduced to a condition of no ridging in the outer feed waveguide by a transition to a single inner ridge which terminates in a tapered star-shaped combination ridge within the outer feed waveguide.

Abstract: A feed system for an antenna has a set of inner and outer coaxial waveguides which apply, respectively, both higher and lower frequency radiations to a common radiating aperture provided by a horn and shroud which envelops radiating apertures of the individual feed waveguides. Each of the feed waveguides carries signals having a bandwidth of an octave. Lower frequency radiation to be transmitted by the outer coaxial feed waveguide is applied thereto by a set of four waveguides of a launcher which launches a wave with a desired propagation mode into the outer feed waveguide. Each of the launch waveguides is initially a rectangular double-ridged waveguide for increase bandwidth. The ridging is reduced to a condition of no ridging in the outer feed waveguide by a transition to a single inner ridge which terminates in a tapered star-shaped combination ridge within the outer feed waveguide.

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 feed structure for an antenna, comprising a feed horn having an input end and an output end, a collar threadably engaged to the output end of the feed horn and a protective window interposed between the feed horn and the collar. The collar forms an aperture exposing said window.

Abstract: An antenna integral-type transmitter/receiver system to be installed outdoors and used for transmission and reception of radio signals. The object is to provide a small, lightweight antenna integral-type transmitter/receiver system formed of the reduced number of parts and assembling steps. The antenna integral-type transmitter/receiver system consists of a housing having one end surface in which an opening is formed and the other end surface in which an antenna mounting surface is formed, and including a transmitter/receiver function unit formed of a waveguide circuit unit, a high-frequency electrical circuit unit, and an intermediate frequency electrical circuit unit; an antenna connected to the transmitter/receiver function unit mounted on the other end surface of the housing; and a cover member for closing the opening of the one end surface of the housing. The waveguide circuit unit and the high-frequency electrical circuit unit form a first unit.

Abstract: An antenna for transmitting or receiving electromagnetic radiation along an axis comprises at least three layers 20a, 20b, 20c, 20d and 20e of dielectric material spaced from one another in a direction perpendicular to the axis. The outermost layers 20a and 20e are spaced from one another by at least half the wavelength of the electromagnetic radiation. The layers extend generally in the direction of the axis from a rear end to a front end of the layers. A transition portion 22 electromagnetically couples the layers 20a, 20b, 20c, 20d and 20e directly to a waveguide 21. A front end of the transition portion 22 is connected to the rear end of the layers 20a, 20b, 20c, 20d and 20e and has a dimension in the direction perpendicular to the axis substantially equal to the spacing between the outermost layers 20a, 20e at the rear end of the layers.

Abstract: An ultra-wideband horn antenna transmits and receives impulse waveforms for short-range radars and impulse time-of flight systems. The antenna reduces or eliminates various sources of close-in radar clutter, including pulse dispersion and ringing, sidelobe clutter, and feedline coupling into the antenna. Dispersion is minimized with an abrupt launch point radiator element; sidelobe and feedline coupling are minimized by recessing the radiator into a metallic horn. Low frequency cut-off associated with a horn is extended by configuring the radiator drive impedance to approach a short circuit at low frequencies. A tapered feed plate connects at one end to a feedline, and at the other end to a launcher plate which is mounted to an inside wall of the horn. The launcher plate and feed plate join at an abrupt edge which forms the single launch point of the antenna.

Abstract: An antenna/amplifier includes a waveguide and an amplifier system. The amplifier and signal lines which terminate in orthogonal probes are carried on a common substrate. The orthogonal probes are spaced from a waveguide wall and isolated for good cross polarization by a post which extends from the wall. The probes have probe tips which are spaced from the post by a probe space. Parameters which include the probe space, the impedance of the signal lines and the length of the signal lines can be selected to present an optimum impedance to low-noise amplifiers of the amplifier system.

Abstract: A portable communication device which has a horn antenna and a transmitter-receiver and in which the horn antenna can readily be attached to and detached from the transmitter-receiver in a short time. In this portable communication device, a flange on the horn antenna side is connected to a flange on the transmitter-receiver side with four clasps etc. The four clasps etc. are arranged at equal intervals around the outer periphery of the interface of a connecting portion. The clasp comprises a fixing hook portion and a pushing-down portion. The fixed hook portion and the pushing-down portion are fixed to the flanges on the transmitter-receiver side and on the horn antenna side, respectively. The clasps etc. can be operated very easily with a single motion. Therefore, the horn antenna can be attached to and detached from the transmitter-receiver in a short time without a tool. Also, this attaching/detaching operation can reliably be performed in the dark without lighting.

Abstract: A connector assembly for connecting a microwave antenna to a radio unit. The connector assembly comprises a central hub including a waveguide and adapts for connection to the antenna for transmitting microwave signals to and from the antenna. A first latching element is attached to the hub and a second latching element adapts for connection to the radio unit and cooperates with the first latching element for latching and unlatching in response to rotational movement of the second latching element relative to the first latching element.

Abstract: A horned interferometer antenna apparatus has parallel plates spaced apart and rigidly connected together by a separator. In the space between the parallel plates is a plurality of antenna elements. The parallel plates each have a free edge which diverge from the other free edge defining an aperture for receiving electromagnetic waves. The horned interferometer antenna apparatus has enhanced directivity and is used for passive radio direction finding. An interferometer system comprises a horned interferometer antenna apparatus, a multi channel receiver and a phase comparator. The interferometer system measures the angle of arrival of an incident electromagnetic wave or signal based on the phase difference between the signal as received by the antenna elements of the horned interferometer antenna apparatus.

Abstract: The feed-horn with helical antenna element of this invention comprises (1) a waveguide made of conductive cylinder having a step inside, the inner diameter in the vicinity of the opening face of the waveguide is larger than that of the base of the waveguide, and (2) a helical antenna element disposed at the base axial center of the waveguide. Introduction of the step-formed inside to the waveguide makes it possible to obtain excellent characteristics both of cross polarization and impedance.

Abstract: A photonic bandgap antenna (PBA) (10') utilizes a periodic bandgap material (PBM), which is essentially a dielectric, to transmit, receive, or communicate electromagnetic radiation encoded with information. Further, a photonic bandgap transmission line (PBTL) (10") can also be constructed with the PBM. Because the PBA (10') and PBTL (10") do not utilize metal, the PBA (10') and PBTL (10") can be used in harsh environments, such as those characterized by high temperature and/or high pressure, and can be easily built into a dielectric structure such as a building wall or roof. Further, the PBA (10') and PBTL (10") inhibit scattering by incident electromagnetic radiation at frequencies outside those electromagnetic frequencies in the bandgap range associated with the PBM.

Abstract: The invention provides a reflector antenna, especially for a communications satellite, having at least one fixed main reflector (102) with an essentially circular aperture. A fixed feed system (118) includes a horn radiator (108) with a rotationally symmetric radiation diagram and a fixed polarization direction. An auxiliary reflector may be arranged to be rotationally positionable around a main axis (E) and has a reflecting surface that is shaped as a partial surface of a nonrotationally symmetric ellipsoid with a low numerical eccentricity, which illuminates main reflector (102) elliptically with an ellipticity that is essentially constant regardless of the rotational position.

Abstract: A feedome is disposed on the side of an opening of a radiator main body, and comprises a dielectric board having a thickness sufficiently smaller than the wavelength of radio wave, and a dielectric protrusion fixedly mounted to the dielectric board substantially in the center of the inner side thereof, and having a height approximately equal to integral number times (1/2).multidot..lambda. where the wavelength of radio wave is .lambda., and a diameter approximately equal to the height of the dielectric protrusion.

Abstract: A microwave horn antenna structure including a plurality of planar dielectric insulating layers stacked in laminar fashion so as to have a bottom layer and a top layer, respective similarly shaped conductive trace loops co-axially disposed on a plurality of contiguous ones of the insulating layers and of incrementally increasing size from a lowermost conductive trace loop an uppermost conductive trace loop, and a plurality of conductive vias extending through the planar dielectric layers for electrically interconnecting the respective conductive trace loops. Also disclosed is a flared notch antenna that includes a plurality of planar dielectric insulating layers stacked in laminar fashion, a slanted column of electrically interconnected conductive vias formed in a plurality of contiguous ones of the dielectric insulating layers and a second slanted column of electrically interconnected conductive vias formed in the contiguous ones of the dielectric insulating layers.

Abstract: A diverging shall antenna fed by a waveguide supplying TE.sub.11 mode is described. A dielectric rod partially contained within the waveguide converts the TE.sub.11 mode to a dominant or HE.sub.11 mode. The HE.sub.11 mode is controllably converted to second and third order modes in the diverging shell by discontinuities placed in predetermined locations in the diverging shell. The discontinuities generating the second mode are incorporated into the dielectric rod structure. Turning of the relative amplitude and phase of the second and third order modes relative to the HE.sub.11 mode is achieved by slideably positioning the dielectric rod. An alternative embodiment of the inventive device includes a reactive surface of the diverging shell.

Abstract: A pyramidal horn antenna that decreases ringing in radar systems that are placed against a solid volume of e.g. concrete or wood for finding an object in or behind the solid volume. The antenna includes a solid, pyramid-shaped dielectric, the pyramid shape including a rectangular base and four triangular sides that extend from the base to meet at the apex of the pyramid. Two conductive triangular plates overlay opposite ones of the four sides of the pyramid, each of the plates including an electrical connection for coupling the plate to a radar system. The pyramid-shaped dielectric has a dielectric constant that approximates the dielectric constant of the solid volume, and therefore provides an impedance match between the antenna and the solid volume.

Abstract: A single integrated antenna feed transmits and receives electromagnetic waves in the C, X, and Ku frequency bands. This antenna feed includes an inner metal tube which lies along a central axis, and an outer metal tube which surrounds and is coaxial with the inner metal tube. Through the inner tube, a passageway is provided which is sized to carry electromagnetic waves in the X-band and Ku-band, but reject electromagnetic waves in the C-band. Between the inner tube and the outer tube, another passageway is provided which is sized to carry electromagnetic waves in the C-band. An I/O port for the X and Ku-bands is provided by a first end of the inner tube, and an I/O port for the C-band is provided by a corresponding first end of the outer tube. This first end of the outer tube lies proximate to but not past the first end of the inner tube. A solid dielectric is inserted into and fills the first end of the inner tube; and, a hollow metal cone is attached to the first end of the outer tube.

Abstract: An antenna pointing detection system for use with circularly polarized electromagnetic radiation has a horn, a waveguide and at least one mode switching arm. The horn receives radiation in a primary mode from the radiation source. The waveguide receives radiation from the horn and supports only radiation in a primary mode, e.g. the TE.sub.11 mode and the next higher order TE mode, e.g. the TE.sub.21 mode at one or more rectangular mode switching arms extending from the circular waveguide for stimulating radiation of the-next order TE.sub.21 mode in the waveguide. The arm has a series of switchable pin diodes for changing the effective length of the mode switching arm to cause a phase alteration in the TE.sub.21 mode thereby causing a deflection of the effective pointing direction of the horn. The magnitude of the received signal is detected and compared with different deflections of the horn to operate conventional antenna pointing hardware.

Abstract: An elliptic beam antenna easy to design and simple in structure. To generate elliptic beams of about the same size regardless of the kind of polarized waves for excitation, a horn antenna or waveguide structure intended for radiating out radio waves into space features the provision of diamond aperture, modified from the conventional circular, elliptical, square or rectangular one and excitation of radio waves in diagonal directions.

Abstract: An antenna for radiating UWB RF pulses is disclosed. The antenna may incl a transverse electromagnetic mode (TEM) horn antenna section connected to a pair of a resistively loaded parallel plates. Each of a pair of protrusions may be connected one of the parallel plates and a shunt network is connected to the parallel plates. Each of said parallel plates includes a plurality of plate segments having varying widths. The protrusions may have a geometric shape such as a quadrilateral, rectangle, square semi-circle or triangle. The protrusions may be made of metal such as copper or aluminum or a resistive material such as carbon. Alternatively, the protrusion may be made of plated PC board such as glass epoxy or duoroid, a carbon composite or fiber glass plated with a conductive material such as copper, tin or carbon. This invention may also be used for narrow band applications, as the shunt network can be tuned to null certain frequency ranges.

Abstract: A high-frequency integrated circuit which operates in a microwave band or in a millimeter wave band. The high-frequency integrated circuit has devices with a nonradiative dielectric waveguide such as an oscillator, a circulator, etc., and a mount case with a nonradiative dielectric waveguide in which these devices are mounted. Each of the devices with a nonradiative dielectric waveguide has a couple of conductors, a dielectric strip which is disposed between the conductors and propagates a high-frequency electromagnetic wave in a specified mode, a mounting surface which is formed on one of the conductors, and an end surface which is formed on an end of the conductors so as to be vertical to a traveling direction of the electromagnetic wave propagated in the dielectric strip and on which an end of the dielectric strip is exposed. The devices with a nonradiative dielectric waveguide are evaluated separately, and thereafter, the devices are mounted in the mount case individually.

Abstract: An antenna device for receiving a radio wave transmitted from a communication satellite, converting the received radio wave into an electric signal, amplifying the signal, and outputting the amplified signal to a receiver is capable of quickly resuming a radio wave reception in the event of a failure. The antenna device includes a converter assembly having a straight waveguide and a twisted waveguide for supplying polarized radiowaves in the same direction to two LNBs, which are oriented in the same direction and fixed to a fixing adapter that is slidably mounted on a holder unit. Even when one of the LNBs suffers a failure, the other normal LNB can be used as a spare LNB and simply moved to replace the malfunctioning LNB. Therefore, any malfunctioning LNB can be replaced easily for quick resumption of a radio wave reception. A satellite communication reception system employs such an antenna device.

Abstract: A velocity detecting radar unit that is easy to operate and to view so as to minimize distraction to the operator, particularly when in use in a moving vehicles includes a spotlight unit having a housing with a lens, a light source within the housing and a control wand pivotally mounting the housing for rotation about an axis and including an elongated tube adapted to extend through the windshield pillar of a vehicle. A radar antenna is mounted in the housing to be movable therewith and has a radar transmitting and receiving end extending from the housing oppositely of the spotlight lens. A display module is adapted to display velocity data and other information and is adjustable mounted to the tube at a location thereon remote from the spotlight housing. Similarly, an input or control module including function switches for providing function commands to a controller for the unit is provided and is adjustable mounted to the tube at a location thereon remote from the housing.

Abstract: An assembly of antenna elements is mounted in a unitary structure for transport on a satellite encircling the earth. Each element comprises a horn shaped radiator with opposed arcuate sidewalls, a rectangular waveguide feed, and a transition interconnecting the feed to a throat of the horn. The assembly services a plurality of portions of a communication band within the electromagnetic spectrum. The throats of respective horns are dimensioned for specific frequencies of the respective portions of the communication bands. The antenna elements may provide telemetry and control functions for the satellite. A side-by-side arrangement of the horns permits use of a common meanderline polarizer for conversion of a linearly polarized wave to a circularly polarized wave for each antenna element.

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 portable communication device which has a horn antenna and a transmitter-receiver and in which the horn antenna can readily be attached to and detached from the transmitter-receiver in a short time. In this portable communication device, a flange on the horn antenna side is connected to a flange on the transmitter-receiver side with four clasps etc. The four clasps etc. are arranged at equal intervals around the outer periphery of the interface of a connecting portion. The clasp comprises a fixing hook portion and a pushing-down portion. The fixed hook portion and the pushing-down portion are fixed to the flanges on the transmitter-receiver side and on the horn antenna side, respectively. The clasps etc. can be operated very easily with a simple motion. Therefore, the horn antenna can be attached to and detached from the transmitter-receiver in a short time without a tool. Also, this attaching/detaching operation can reliably be performed in the dark without lighting.

Abstract: A corrugated horn having ridges disposed on the inner surface of the horn, such that the ridges are oriented parallel to the horn axis, is adapted to provide elliptical beams. When the corrugated horn is circular, the elliptical beam is produced by changing the step heights and/or ridge heights around the circumference of the horn, which in turn changes the semi-flare angle, defined as the angle made by the horn axis and a line joining the top surfaces of the ridges. Because corrugated horns constructed according to this invention have ridges oriented parallel to the horn axis, these corrugated horns are readily manufactured using conventional die casting methods or numerical machining techniques.

Abstract: A dielectric rod antenna including a dielectric rod, a ring-shaped conductive film provided on an outer peripheral surface of the dielectric rod, and a waveguide. The conductive film is provided on an outer peripheral surface portion of the dielectric rod which is inclined from a base end portion toward a forward end portion. The conductive film is arranged to intersect the waveguide so as to form a substantially V-shaped cross-sectional area.

Abstract: A flat planar antenna formed from a flat this substrate coated on one surface with a electrically conductive material except for a first uncoated funnel shaped cavity with a large mouth beginning along one outer surface of the substrate and diminishing in cross-section toward the center of the substrate with a diminishing width down to an extended neck portion which extends to an outer substrate surface normal or parallel to the substrate surface adjacent to the mouth. A smaller tuning cavity may be positioned over the neck portion adjacent to the edge of the substrate. The antenna may have feed lines plated on the opposite surface from the funnel shaped cavity, hard wired through the substrate to the opposite side thereof or formed by micro stripline techniques. A second embodiment employs unplated side cavities between the funnel unplated area and the edges of the substrate normal to the funnel mouth.

Abstract: A plurality of dual mode, dielectric resonator loaded cavity filters may be coupled to respective ones of a plurality of radiators of an array antenna, such as a phased array antenna. Each of the filters is provided with a thin annular, electrically conductive ring disposed on a resonator surface facing the corresponding radiator of the antenna. The ring greatly increases the coupling of electromagnetic power for circularly and linearly polarized waves between the filter and the radiator for radiation of the power from the radiator into space, as well as during reception of radiation from outer space. The filter is operative also, if desired, to provide such coupling of electromagnetic power to a waveguide, as well as directly into the external environment. The ring may be located at the opening of the cavity through which the power is coupled between the filter and the radiator or the waveguide or the empty space.

Abstract: A spatial power combiner includes a circularly corrugated horn 26, a meniscus lens 28, an amplifier array 16, and a layer of microwave absorbing material 34 on a housing interior 32. The lens 28 receives polarized microwave radiation from the horn 26 and collimates it, renders it in phase and with nearly uniformly amplitude, and distributes it across the lens aperture. The amplifier array 16 amplifies the radiation and re-radiates it, orthogonally polarized, to the lens 28, which focuses it back down the horn 26. An array of parasitic micropatches 24 between the lens 28 and amplifier array 16 provides impedance matching. A quarter-wave anti-reflecting coating 30 covers both surfaces of the lens 28. The microwave absorbing material 34 reduces or prevents resonance of higher order modes.

Abstract: A conical corrugated microwave feed horn. A conical flare section is formed at the aperture of the feed horn and a second smooth cylindrical section is formed at the throat of the feed horn. The conical flare section is formed with two regions. The first region is a corrugated conical region formed at the aperture and having a plurality of slots formed parallel to the central axis of the feed horn. Each slot in the plurality of slots has an inner surface closest to the central axis of the feed horn and an outer surface furthest from the central axis. Connecting the corrugated conical region to the cylindrical throat is a smooth conical region. The first slot adjacent the smooth conical region has first and second formed lips on the terminating end thereof. The lips are formed directed inwardly toward each other. The last slot of the plurality of slots at the aperture of the feed horn has the terminating end of the inner surface extending in length beyond the length of the outer surface.

Abstract: An antenna for radiating ultra wide bandwidth radio frequency pulses for in communications systems and sensors is disclosed in which a TEM horn is loaded by a resistively loaded parallel plate section and a shunt network connected to the parallel plate section in order to provide a low VSWR high efficiency antenna.

Abstract: This invention is a multiple channel microwave polarization rotator with external rotary mechanical energy coupling. It finds application in microwave polarization rotators, resolvers, amplitude modulators, and other devices. The device consists of a plurality of collinear axially spaced waveguide cavities sequentially located inside one another. A rotatable conductor, capable of continuous rotation, located within each waveguide cavity is electrically coupled to a stationary transmission line and mechanically connected to rotational devices outside of the transmission line system. The rotatable conductors are connected by nonconductive drive means enabling successive coupling probes to rotate determining the polarization of electromagnetic waves by the rotational position of the coupling probes within the waveguides. The electrical and mechanical couplings are completely independent.

Abstract: A feed structure (24) is disclosed for reception of orthogonal linearly polarized signals from communication satellites. The structure includes probes (34, 36) extended through the back wall (32) of a cavity (28) with associated transmission members (50, 52) and an associated isolation member (54). The teachings of the invention are extended to structures having the probes extended through the side wall (100) of a cavity. The teachings of the invention are further extended to dual band feed structures (124, 220 and 320). The structures are particularly suited to enhance high signal to noise ratios because of short path lengths to external receiver circuits and to enable realization in simple economical one piece castings.

Abstract: A dual band signal receiver is provided with relatively coaxial antenna assemblies electromagnetically coupled to respective upper and lower band rectangular waveguides and ports through suitable polarization switching assemblies. The upper band rotatable antenna assembly consists of a dipole feed having driven dipole elements, parasitic dipole elements and a corner reflector element electromagnetically coupled to the upper band rectangular waveguide by a suitable transmission line extending substantially along the longitudinal axis or centerline of the lower band cylindrical waveguide.

Abstract: An active array antenna, which may be used for radar, includes antenna elements (antelements) supported in a two-dimensional array. The fronts of the elements are protected by a cover. In order to allow easy repair, each column of antelements is associated with a slide-in carrier which simultaneously mates with all antelements of a column. Each carrier has a transmit-receive (TR) module for each antelement with which it mates, and a column beamformer. Each carrier also has logic modules and power supplies for the TR modules. The total width of each slide-in carrier with its TR modules, beamformer, logic and power supplies, is less than or equal to the column-to-column spacing. Each carrier can be slid out from the rear to expose all the active components for each column of antelements, so maintenance can be performed without environmental exposure.

Abstract: A double ridge flared trough radiating element, including a double ridge trough waveguide fed by an embedded coaxial or stripline feed network. Energy couples smoothly to and from the feed network and trough waveguide because the equivalent characteristic impedance at the feed point of the shunt connected waveguide is the same as the feed network characteristic impedance. The radiator can be configured to produce linear, dual-linear or circular polarization.

Abstract: Signal propagation apparatus is formed with a waveguide cavity for propagating first and second electromagnetic signals respectively having first and second electric fields that are distinguished outside the cavity by first and second polarizations, for example orthogonal polarizations, one vertical and one horizontal. Within the cavity, the electric field lines are curved and cross one another at angles that vary as a function of location within the cavity. A pair of probes are mounted within the cavity in spaced-apart relation to each other and have orientations that differ from the orientations of the electric fields outside the cavity. In order to send or transmit signals having electric fields that are respectively vertically and horizontally polarized, for example, thereby forming an angle of 90.degree. with respect to each other, the probes lie in planes forming a dihedral angle of about 80.degree..

Abstract: Heat dissipation problems in a sealed radar antenna unit are avoided in a construction including a generally cylindrical body (10) of metal having opposed ends (12, 14) and an interior, cone shaped chamber (16). The cone shaped chamber (16) has a wide opening (18) at the end (12) at a narrow opening (20) at the end (14). A plurality of peripheral grooves (30, 32, 34, 36 and 38) extend about the periphery of the body (10) between the ends (12), (14) thereof to define heat dissipating fins (40) integral with the body (10).

Abstract: The ferroelectric scanning RF antenna includes a ferroelectric material having conductors deposited thereon that are connected to an adjustable d.c. or a.c. voltage source. The scanning antenna is placed in an RF transmission line that includes appropriate input and output impedance matching devices such as quarter-wave transformers. The scanning section of the RF scanning antenna is constructed of two prismatic structures of a ferroelectric material. When the two prismatic structures are at the same zero bias voltage, then the RF energy passing through the antenna is not deflected and a boresight radiation pattern is obtained. Application of a bias voltage reduces the permittivity and the refractive index of the outer prismatic structure. The RF energy is refracted away from the normal at the interface between the prismatic surfaces and the radiation pattern is scanned in one direction. Application of a bias voltage reduces the permittivity and the refractive index of the inner prismatic structure.

Abstract: A structure for use in an antenna or as a broadband electromagnetic field simulator, having an open horn TEM waveguide coupled to launch energy in a strip line formed between a forwardly extending plate section and a ground plane. When used as a simulator the test volume is located outside the horn between the forwardly extending plate section and the ground plane. The plate section which functions as a radiating element initially extends parallel to the ground plane and then curves downwardly to terminate adjacent it. In alternative embodiments the plate section extends upwardly, initially with an exponential configuration. In a simulator embodiment it may then terminate at a vertical, grounded wall faced with anechoic material. The horn contains a flat conductor plate positioned parallel to and spaced from the top edge defining an asymmetrical transmission line within the horn.

Abstract: A parabolic-reflector antenna having a primary horn including first, second, and third hollow portions. The first hollow portion has an elliptical aperture on one end thereof and a circular cross section on an opposite end thereof, and is progressively tapered away from the elliptical aperture. The second hollow portion has a circular cross section and a constant diameter, and is joined to the opposite end of the first hollow portion. The third hollow portion has a circular cross section on one end thereof and a circular cross section on an opposite end thereof. The third hollow portion is joined to the opposite end of the second hollow portion, and is progressively tapered away from the second hollow portion. The parabolic-reflector antenna also includes a parabolic reflector having an elliptical aperture whose major axis is perpendicular to the major axis of the elliptical aperture of the primary horn.

Abstract: A microwave antenna has a circular wave guide feedhorn mounted above a reflector. An electrically insulating sleeve fits around the outer diameter of circular wave guide. A scalar ring is secured to the insulating sleeve. The sleeve isolates the ground of the circular wave guide from the reflector and scalar ring so that electrostatic charge accumulating in the reflector does not damage electronic components electrically coupled to the wave guide.

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: A simulation device is provided for testing autotrack antennas. The device includes a mode coupler and transmit horn which are identical to the mode coupler and transmit horn of the antenna to be tested. The mode coupler has a plurality of waveguide input ports for transmitting voltage signals which are complex conjugates of signals occurring under receiving conditions. The device then generates a signal that simulates the far-field, plane-wave testing environment and applies this signal to an antenna to be tested.