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

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

Abstract: A trough waveguide antenna that has a septum and opposing bases and side walls. In one embodiment, the bases are undulated and asymmetrically disposed about the septum. The magnitude, periodicity and length, etc., of the undulations may be varied for performance. The configuration of the septum may be similarly varied. Other mechanisms for achieving energy radiation are also disclosed as are cost effective fabrication techniques.

Abstract: According to the present invention, there is provided a satellite broadcast receiving converter which comprises a waveguide in which the broadcast wave travelling therein travels as a first TE11 mode linearly polarized wave and as a second TE mode linearly polarized wave intersecting at a right angle with each other, a first probe disposed at a predetermined position within this waveguide for detecting the first linearly polarized wave, a first reflecting conductor disposed approximately 1/4 of the wavelength separate from the first probe in the direction in which the electric wave travels for reflecting the first linearly polarized wave, a second probe disposed in the neighborhood of the first reflecting conductor for detecting the second linearly polarized wave, and a second reflecting conductor disposed approximately 1/4 of the wavelength from the second probe in the direction in which the electric wave travels for reflecting the second linearly polarized wave.

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 pair of adjacent antennas are configured to transmit and receive wideband signals with low direct coupling. The antennas are horns with extended walls and a shaped septum. At a typical operating frequency of 5.8 GHz, coupling levels are as low as -60 dB. Low coupling levels are needed to reduce measurement errors in radar rangefinders operating at less than 1-meter target range.

Abstract: A wireless communication system that utilizes a circularly polarized transmitting antenna with dual orthogonal circularly polarized receiving antenna. According to some embodiments, the present invention provides a wireless communication system that includes a first transmitting antenna capable of transmitting first signals having a first type of circular polarization. The transmitting antenna is located at a first location. The system also includes a first receiving antenna capable of receiving second signals having a second type of circular polarization, where the second type of circular polarization is orthogonal to the first type of circular polarization. The system further includes a second receiving antenna capable of receiving third signals having the first type of circular polarization, and the first receiving antenna and the second receiving antenna are both located at a second location.

Abstract: A lens antenna having high antenna efficiency, low sidelobe levels, and that is easily assembled. The lens antenna includes a first horn made of a metallic conductor, a second horn made of a high-frequency absorbing plastic material, and a lens for controlling the power distribution at an aperature of the horn. Screws may be used to assemble the first horn, the second horn, and the lens. Though some of the microwave signals input through the circular waveguide of the first horn are reflected on the surface of the lens, most of the microwave signals are absorbed by the second horn. Moreover, because no wave absorber is bonded to an inner wall of a conical horn, nothing screens the microwave signal, the power density distribution at the aperture of the lens is not disrupted. Therefore, it is possible to obtain a desired power density distribution.

Abstract: A low profile, receiving and/or transmitting antenna is adapted to be mounted onto an interior portion of a building or other structure to receive or transmit radiation through a first dielectric material, such as a window, associated with the building or other structure. The antenna includes a receiving/transmitting horn filled with a second dielectric material and a surface for mounting the antenna to the first dielectric material so that the horn is disposed at a particular angle with respect to a surface of the first dielectric material. A matching layer may be disposed between the first dielectric material and the second dielectric material to provide for a reflectionless match between the first and second dielectric materials.

Abstract: A tapered slot plane antenna apparatus for a millimeter wave radio communication system which provides a tapered pattern composed by utilizing a Fermi-Diac distribution function so as to consider an impedance matching and a directivity of the antenna apparatus. Supporting layers and protection layers may be utilized to provide sufficient strength for implementation in a compact millimeter wave radio communication system. The plane antenna may further prevent a directivity from deteriorating even if distances between end portions of an antenna aperture portion and ends of an antenna are decreased. A slot width of a slot line may be widened in tapering for radiating an electromagnetic wave in a progressive direction of the slot line by a conductor portion having a slot line and a corrugated structure portion at respective end portions located parallel to a radiating direction of the electromagnetic wave.

Abstract: A single radiating structure with an integrated mode transducer that produces near-ideal radiation characteristics at two frequency bands. The dual band feed consists of three main sections: feed waveguide, mode transducer and corrugated horn. The feed waveguide consists of two concentric, circular waveguides that are excited in the TE.sub.11 coaxial and circular waveguide modes for the low and high bands, respectively. The mode transducer, which is critical to the performance of the feed, provides a single mode, low return loss transition, for both bands, between the feed waveguide and the corrugated horn. This is achieved by converting the TE.sub.11 circular waveguide modes into the fundamental hybrid, HE.sub.11, mode of the corrugated horn. The corrugated horn, which is a stepped-slot configuration, is designed to achieve a smooth transition from the mode transducer and to produce the desired radiation characteristics at both frequency bands.

Abstract: A heater assembly for use with a feedhorn in an antenna system includes at least two heater bodies, with each heater body being configured to be placed directly against the feedhorn at an exterior periphery of the feedhorn. Each heater body has at least one heater disposed therein, with all of the heaters being electrically connected together. A plurality of springs are connected at opposite ends thereof with adjacent heater bodies. The plurality of springs hold the heater bodies against the feedhorn.

Abstract: A dual mode horn reflector antenna for providing an antenna pattern having symmetrical beamwidths over a bandwidth of approximately 40%. An input TE.sub.10 rectangular mode signal is provided to the dual mode horn reflector antenna which generates a first TE.sub.11 circular mode signal from the input TE.sub.10 rectangular mode signal. A first TE.sub.10 square mode signal and a first TE.sub.01 square mode signal are generated from the first TE.sub.11 circular mode signal. The first TE.sub.10 square mode signal and the first TE.sub.01 square mode signal are combined generate a resultant signal. The resultant signal is incident upon a reflecting structure which generates an antenna pattern having approximately equivalent beamwidths in perpendicular planes, and reduced sidelobes.

Abstract: An electromagnetic simulator for testing the behavior of equipment in the presence of strong electromagnetic fields includes radiating horns at opposite sides of a test area. Each horn has a conducting septum asymmetrically positioned in the horns and extending forwardly into the chamber. Each conducting septum is coupled to a conducting array extending along a wall of the chamber so that each array establishes a corresponding electromagnetic field in the test area.

Abstract: A satellite antenna alignment device is described for use with a satellite antenna to enable the satellite antenna to be aligned with respect to a particular satellite. The alignment device is operatively secured to the support arm of the satellite antenna and includes a compass for indicating the directional position of the support arm and also includes a clinometer.

Abstract: An improved reflector antenna with far improved return loss than prior art subreflector antennas is disclosed herein. The invention uses a circular waveguide antenna feed employing a non-planar, subreflector having a radial cavity which reflects the energy from the waveguide onto a rotationally symmetrical main reflector. The dimensions of the feed tube, the subflector, and the connection between them are chosen to make the total reflection back into the feed tube very close to zero. The dimensions of the antenna feed are also chosen such that its radiation pattern has an amplitude null along the antenna feed axis. This further improves return loss by minimizing the amount of energy from the main reflector that gets directed back into the feed tube. An alternate embodiment features a feed radiation pattern with an asymmetric amplitude taper for improvement of the sidelobe envelope in a preferred plane.

Abstract: The inline coaxial balun fed cornu flared horn antenna is formed by transitioning a coaxial transmission line to a parallel-plate transmission line with a Klopfenstein impedance profile and terminating with a flared horn antenna based on a scaled cornu spiral. The cornu spiral is a mathematical plane curve formed by parametrically plotting the scaled cosine Fresnel integral versus the scaled sine Fresnel integral. The antenna has the property that the curvature of the flare increases linearly in proportion to the arc length of the flare. The Klopfenstein impedance profile of the inline balun ensures a low voltage reflection across a wide bandwidth with a minimum transition length and together with the cornu flare satisfies the requirements for a wideband design.

Abstract: A receiving antenna includes a parabolic reflector and a feed horn. The feed horn includes an electrically conductive wall with an edge forming an aperture. The feed horn further includes a plurality of electrical conductors that extend from the edge to the center of the feed horn in a substantially coplanar relationship with the aperture. Each of the electrical conductors differentially affect a first polarized electrical field perpendicular to the edge adjacent the electrical conductor and a second polarized electrical field parallel to the edge adjacent the electrical conductor. In this manner, the electrical conductors can be configured to reduce the effective aperture of the feed horn in a plane, so that a first polarized horn radiation pattern produced by the feed horn can be circularized.

Abstract: An antenna shroud or clutter fence has edge treatment for redirecting or absorbing energy which would otherwise be diffracted in an undesired direction. The edge treatment can include an array of corrugations which are about .lambda./4 deep for scattering sidelobes. The array of corrugations can be parallel to either the E-wave component or the H-wave component. Alternatively, the edge treatment can include an array of antennas encased in a dielectric extension.

Abstract: Apparatus is provided for allowing two high frequency signals from two separate sources to be combined for simultaneous propagation through a common propagation medium such as an antenna or transmission line, while maintaining isolation between the signals at the inputs of the sources and preventing unwanted interference and resulting distortion. The apparatus includes an orthogonal mode converger which receives two combined electromagnetic energy waves having orthogonally disposed electric field vectors and incrementally converges them to the same direction through a varying cross-section waveguide structure.

Abstract: An improved transverse electromagnetic (TEM) horn antenna comprises a resistive loading material on the exterior surfaces of the antenna plates. The resistive loading material attenuates or inhibits currents on the exterior surfaces of the TEM horn antenna. The exterior electromagnetic fields are of opposite polarity in comparison to the primary and desired interior electromagnetic field, thus inherently cause partial cancellation of the interior wave upon radiation or upon reception. Reducing the exterior fields increases the radiation efficiency of the antenna by reducing the cancellation of the primary interior field (supported by the interior surface currents). This increases the transmit gain and receive sensitivity of the TEM horn antenna, as well as improving the transient (time-domain) response.

Abstract: An arrangement is provided for combining the video and audio signals from a satellite antenna with other auxiliary input signals producing a frequency stacked band arrangement for transmission by a single cable to a satellite receiver or TV monitor located within a home or structure. Multiple TV input signals from the satellite antenna are processed and separated into intermediate frequency bands which are then combined in a diplexer with one or more auxiliary input frequency bands. The output of the diplexer is connected directly to the signal output terminal at the antenna. All components for performing this combining process are included within the sealed housing of the LNB provided at the satellite antenna. Improved band isolation and reduced noise and interference are produced by the novel arrangement.

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

Abstract: In a microwave transmission system a microwave signal is transmitted by a transmitter (1) using an antenna (2) to a receiver (4) which employs an antenna (3). The received signal is coupled to a mixer (17) via a waveguide section (15) having a cut off frequency being higher than the frequency of the signal generated by the local oscillator unit (18). In this way undesired emission of local oscillator signal is avoided. Furthermore no additional image rejection filter is required.

Abstract: A lens antenna is disclosed which comprises a conical horn and a lens attached to an aperture of the horn. The lens has a first planar surface at a first side which faces free space and a hyperboloid of revolution at a second side opposite the first side and is made of a dielectric material with relative permittivity ranging from 2 to 4. The lens is provided with a cylindrical portion which has a second planar surface parallel to the first planar surface and displaced from the first planar surface by a predetermined distance. The cylindrical portion being concentric with the lens.

Abstract: A waveguide feed is fabricated by first creating a lead frame (10) from a piece of conductive material. The lead frame (10) is shaped by bending arms (22) and probe portions (18) on the lead frame (10) into a desired shape. The lead frame (10) is then placed in a mold and dielectric molding material is added around relevant portions of the lead frame (10). After the dielectric molding material has solidified, excess molding material and extraneous portions of the lead frame (10) are removed from the molded feed assembly. The assembly can then be connectorized and inserted into a waveguide.

Abstract: A flared trough waveguide antenna capable of being used at high microwave and millimeter wave frequencies is disclosed herein. The antenna includes a conductive trough having first and second ends, a bottom surface, and first and second opposing side surfaces electrically coupled to the bottom surface. A conductive fin is electrically coupled to the bottom surface between the first and second opposing side surfaces. The bottom surface includes a first planar portion between the conductive fin and the first side surface, and a second planar portion between the conductive fin and the second side surface. The conductive trough may be induced to radiate electromagnetic energy by introducing an offset between the first and second planar portions with respect to the plane of the conductive fin. The antenna further includes first and second flared surfaces, respectively coupled to the first and second side surfaces, for directing electromagnetic energy radiated by the flared trough waveguide antenna.

Abstract: A dual-band feed for use in a microwave reflector antenna. The feed for one band is a an open-ended waveguide or a horn-type feed and the feed for the second band is a helix antenna. The wave-guide or horn-type antenna is located inside of the helix antenna and concentric with the helix antenna so as to cause the beams from the two feeds that are reflected by the reflector to be directed in the same direction.

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 biconical antenna having fully adjustable design parameters. The biconical antenna has a coaxial feed having outer and inner conductors. A lower support structure secures a lower cone to the outer conductor. An upper support structure secures an upper cone to the inner conductor. A dielectric window support is disposed between the lower and upper support structures. To make the antenna relatively lightweight, each cone may be made of sheet metal plates that are connected to the lower and upper cone support structures. A reservoir is formed within the upper cone. Dielectric material, such as oil, is disposed within the antenna. Air bubble escape holes are disposed in the upper support structure so that air bubbles that are formed at the coaxial feed can escape to the reservoir. The holes do not allow electromagnetic power leakage between the coaxial feed and the reservoir, and the position of the holes is such that the air bubbles rise from the coaxial feed into the reservoir.

Abstract: A device is indicated for covering the aperture of an antenna having a parabolic reflector and an exciter. The cover is made of a rigid material. The cover includes a shield ring connected to the reflector and a plastic cover shaped like a flat or obtuse cone having a conical portion which closes the open end of the reflector. The wall of the conical portion of the cover forms an angle between 4.degree. and 6.degree. with a plane that is at a right angle to the axis of the shield ring.

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 microwave antenna feed spoiler for reducing side lobes of a microwave antenna with a feed support. The microwave antenna feed spoiler provides one or more segments of electrically conducting surface forming a roof which is coupled to and hides beneath it at least a portion up to the whole length of the feed support.

Abstract: A waveguide horn has septums to decrease the side lobes in its E-plane radiation pattern and the input ends of the septums are spaced from the horn's rectangular input port to improve the return loss of the horn. The input ends are preferably spaced from the input port >3a in which a is the dimension of the broad side of the input port.

Abstract: A broadband horn-like, linearly polarized antenna element is driven from a microstrip line and a balun. The horn is skeletonized, and has no sides, and consequently operates in TEM mode for broad frequency bandwidth. In another embodiment, two or more baluns feed the horn-like antenna element, thereby allowing a plurality of amplifiers or other sources to be combined at the antenna, for power summation or for multiplexing. An array of such elements, arranged for both vertical and horizontal polarization, makes a structure which presents mostly metallic surfaces, and is therefore rugged, and overpressure resistant.

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: An ultrawideband transverse electromagnetic mode horn antenna for use at high voltages, comprises a pulse generator (1) and two transmission horns (12, 18) containing different dielectric media. The interface (30) between the dielectric media is configured so that a signal from the generator is incident on the interface at an angle substantially equal to the Brewster angle, thereby maintaining a good impedance match across the interface. A further advantage of the arrangement is that the TEM wavefront is preserved through the antenna section allowing operation at fast pulse risetime (less than 200 ps) for short duration (several ns) at high voltage.

Abstract: An end-fire array antenna achieves improved performance with an array of radiative members that are arranged collinearly between an array first end and an array second end and a divergent reflector which is arranged collinearly with the radiative members. The radiative members are spaced to facilitate radiation and reception of electromagnetic signals in an antenna direction which extends from the array second end and the divergent reflector is spaced from the array first end to enhance this radiation and reception. A wall of the reflector preferably diverges from an antenna axis by an angle in the region of 24 to 48 degrees. The divergent reflector terminates in an open end which has a transverse width that preferably exceeds 1.4 .lambda..sub.dsgn wherein .lambda..sub.dsgn is the design wavelength of the antenna. In-service antennas are modified with a divergent reflector that is configured for coupling to an existing antenna back wall or antenna cup.

Abstract: Horn antenna (10) produces an electromagnetic energy field and includes waveguide (12) for generating an electromagnetic field having an electric field (52, 54, 56) and magnetic field (58 and 60). Horn portion (14) expands the electric field (52, 54, 56) and magnetic field (50, 60), and produces therefrom an electromagnetic energy field (34) at radiating aperture (29) of horn portion (14). Dielectric portion (32) is positioned within horn portion (14) and includes a sheet (32) of dielectric material that has a relatively uniform thickness. The dielectric portion (32) is placed across horn portion (14) perpendicular to electric field (52, 54, 56) to yield cosinusoidal electromagnetic field (34) at radiating aperture (29).

Abstract: An arrangement is provided for generating and transmitting microwaves, in particular for a filling level measuring device, which arrangement generates a microwave mode which has a radiation characteristic with a pronounced forward lobe and which arrangement can be used in a large frequency range. It comprises a microwave generator (1), an antenna (2) of circular cross section and a coaxial line (3), which leads from the microwave generator (1) to the antenna (2) and has an inner conductor (31) and an outer conductor (32), and has the feature that on a rear wall (21) of the antenna (2) there is arranged a transmitting wire (5), which runs in the interior of the antenna (2), the first end (51) of which is connected to the inner conductor (31) of the coaxial conductor (3), the second end (52) of which is connected to the rear wall (21) of the antenna (2) and which has a straight portion (53) and legs (54, 55) adjoining the latter.

Abstract: A feeder horn for two-way satellite telecommunications includes a center transmitter/receiver horn (10) and at least three separate measuring (11, 12, 13) which are positioned symmetrically relative to the symmetry (O) of the feeder horn.

Abstract: A feed structure for transmitting or receiving microwave energy to or from a reflector includes a waveguide having an input section, intermediate section, and output section. The waveguide has an inner surface of generally rectangular cross section and an outer surface of generally circular cross section. The outer surface includes unique opposing convex surfaces which enables the waveguide to be bent with minimal resulting deformation of the internal rectangular surface. At least one locating surface is provided on the outer surface of the waveguide for determining the orientation of the waveguide. The input section of the waveguide has a threaded cylindrical surface adapted to be connected to a hub having a threaded interior bore which is connected to the reflector. A feed horn integral with the output section of the waveguide and having a circular output aperture is formed by machining the inner surface of the waveguide into a rectangular to circular transition.

Abstract: A steerable feeder link antenna is formed of a steerable reflector and a stationary feed horn assembly. A novel feed horn assembly allows dual mode transmit and receive functions for circularly polarized microwaves. The feed horn assembly includes a four arm turnstile junction coupled to a feed horn through the feed horn's side wall to couple transmit frequencies and an axially coupled transmission line for the receive frequencies. Each turnstile junction arm incorporates chokes for the receive frequencies. The transmission line's cut off frequency is above the transmit frequency to prevent transmit signals from interfering with receive signal receivers.

Abstract: A tapered notch antenna structural panel array that can serve both as a structural member and an antenna is made from an injection molded monolithic three dimensional grid of thermoplastic material. The notch and feed line is in the form of microstrip or stripline circuitry formed to the sidewalls of adjacent cells. Dielectric sheets of material are bonded to the upper and lower edges of the grid. Interconnect circuitry on the antenna ground plane is supported by the sheet bonded to the lower edge and connected to the antenna circuitry of the sidewalls.

Abstract: The invention is directed to a heatable feedhorn assembly including a feedhorn having a wide end and a heater assembly wrapped around the wide end. The heater assembly includes an elongate element in the form of a cable tie and an electrically insulated heater wire wrapped around the elongate element.

Abstract: An electromagnetic wave transmitting and transferring device with high polarization isolation performance is provided which comprises a circular waveguide and a rectangular waveguide. The circular waveguide has a hollow configuration which has an opening at a front end portion and a closed surface at the rear end. The opening of the circular waveguide is provided with a horn. The circular waveguide is provided with a polarizer, a first probe, a metallic post and a closed end surface serving as a conductive back surface, wherein the first probe is perpendicular to the metallic post and each of them are inclined with respect to the polarizer by 45 degrees. The rectangular waveguide is perpendicular to the circular waveguide and the central axis of the rectangular waveguide is in alignment with the first probe. The rectangular waveguide is provided with a second probe and a conductive back surface serving as closed end surface.

Abstract: A radar system is described, which includes a built-in calibration/fault detection apparatus that enables rapid and easy calibration of the system. The system includes a long extrusion (70) forming a feed waveguide (90), a calibration waveguide (92), and a base (94) of a horn antenna. A linear array of TR (transmit/receive) units (42) are mounted on the extrusion, with each having a feed probe (100) that receives a feed signal, changes its phase and amplifies it, and delivers it through a monopole (110) to the horn. The calibration waveguide is coupled through holes (130) to the horn, with a calibration pickup (132) mounted at the end of the calibration waveguide. During calibration, one TR unit at a time is energized, and its output is detected by the calibration pickup to check the amplitude and phase of the TR unit.

Abstract: A flat panel-configured electronically steered phased array antenna includes a planar distribution of densely nested microstrip dipole sub-arrays, arranged and controlled in a manner similar to microstrip `reflect-array` antenna elements. The resultant phase of a circularly polarized wave for a reflect-array fan-out distribution of dipole antenna elements is controlled by an associated plurality of triode-configured field emission devices. Each dipole element sub-array is plated to a resistive sub-layer on an interior surface of a flat first millimeter wave transmissive panel member of an evacuated flat panel type support structure. Mounted to a similar resistive layer on the interior surface of a second, flat panel member is a microstrip conductive layer partially overlapped around its periphery by respective fan-configured microstrip dipole antenna elements plated on the first panel member.

Abstract: A rear feed source for a reflector antenna and an antenna using such a source. The source includes at least one horn connected to a waveguide. The horn has at least two inclined walls forming an aperture, each wall being extended by a wall with a different inclination. This invention can be applied to radars, notably surveillance radars.

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.