Abstract: A satellite assembly 10 is provided, including an RF radiating element 12 including a plurality of RF choke elements 18, each of said plurality of RF choke elements 18 being defined by an RF dimensional set 20 including an RF depth 22 and an RF width 24. The satellite assembly 10 further includes a null aperture field zone 26 created by the plurality of RF choke elements 18, the null aperture field zone 26 created by tuning each of the RF dimensional sets 20. At least one field sensitive component 14 is positioned within said null aperture field zone 26.

Abstract: An apparatus for reducing earth station interference in a receiver antenna from non-GSO and terrestrial sources is disclosed. The apparatus comprises an absorber coupled to a receiver antenna feed assembly disposed between the non-GSO or terrestrial source and the feed assembly. Embodiments are disclosed in which the absorber is strategically placed where it minimally affects the receiver antenna mainlobe performance, while reducing interference from non-GSO and terrestrial sources.

Abstract: A radio wave receiving converter in accordance with the present invention is for receiving satellite broadcast, and includes a body portion having a first feed horn portion, a second feed horn portion connected to first feed horn portion, and a sheet sandwiched between first feed horn portion and second feed horn portion and maintaining air tightness at a connected portion of first feed horn portion and second feed horn portion. An antenna device in accordance with the present invention includes the radio wave receiving converter as described above and a reflective parabolic portion reflecting a received radio wave and leading it to the radio wave receiving converter.

Abstract: The present invention relates to an antenna system for a level measuring device for emitting microwaves by means of an antenna horn (2), at the front side of the smaller funnel aperture thereof, HF energy in the form of microwave signals is directly axially coupled by means of planar structures having one patch or several patches (4).

Abstract: A microwave antenna for use in a sectorized cellular communication system comprises a wide-flare pyramidal horn having two pairs of opposed flared side walls. At least one of the two pairs of opposed walls has corrugated interior surfaces. The length of the horn and the flare angle of the walls having the corrugated interior surfaces are selected to produce a ratio &Dgr;e/&lgr; greater than 1.5, where &Dgr;e/&lgr;=[&agr;/(2/&lgr;)] tan (&agr;e/2) is the spherical-wave error of said horn, &lgr; is the free space wavelength of the microwave signals to be transmitted by said antenna, &agr; is the horn's aperture width, and &agr;e the half-angle of the horn in the horizontal plane.

Abstract: A single receiving aperture used, for example, in an airborne seeker system collects energy for three discrete energy sensors/receivers including a laser spot tracker, an RF (millimeter wave) transmitter/receiver, and an infrared detector. The RF transmitter/receiver is located at the focus of a primary reflector located on a gimbal assembly. A selectively coated dichroic element is located in the path of the millimeter wave energy which reflects infrared energy from the primary reflector to an optical system which re-images the infrared energy on the infrared detector. The outer edge or rim of the primary reflector is deformed so that the incoming laser energy focuses to a location beyond the RF transmitter/receiver. The laser sensor is positioned adjacent the RF transmitter/receiver at this location in a back-to-back orientation. The laser energy is then detected using a secondary reflector and an optical system which directs the laser energy from the secondary reflector to a laser detector.

Abstract: A ridged feed horn antenna for use in broadband satellite communications. This multi-ridged feed horn operates in a receive band of 10-13 GHz and a transmit band of 14-15 GHz. The ridged feed horn antenna comprises excitation conductors which excite the field between each of the ridges in the feed horn antenna. The excitation conductors are connected to each of the ridges. A waveguide, terminated at the back of the horn antenna, enables the ridges to guide the energy from their respective excitation conductors toward the mouth of the feed horn antenna. A planar balun and matching circuit, located at the back of the horn antenna, may be used to feed each of the excitation conductors. Furthermore, the cross-section of each excitation conductor is chosen so as to optimize horn antenna performance. Each excitation conductor extends outwardly from the back of the horn and is parallel to the longitudinal axes of the horn waveguide.

Abstract: In a satellite receiver a feeder element is provided that includes several feeder horns on a micro head for distributing satellite signals from different satellites to different channels in the different horns and means for blocking all channels, except for the one that is presently desired to be used, before the signals sent on these channels reach the micro head.

Abstract: The present invention provides a dielectric leaky-wave antenna having a single-layer structure which is effective for realizing a highly efficient low-cost antenna in a quasi-millimeter wave zone in particular. This dielectric leaky-wave antenna includes a ground plane, a dielectric slab which is laid on one surface of the ground plane and forms a transmission guide for transmitting an electromagnetic wave from one end side to the other end side between itself and the ground plane along the surface, perturbations which are loaded on the surface of the dielectric slab along the electromagnetic wave transmission direction of the transmission guide at predetermined intervals and leak the electromagnetic wave from the surface of the dielectric slab, and a feed which supplies the electromagnetic wave to one end side of the transmission guide.

Abstract: The present invention relates to antenna feeds (10, 30, 70, 78, 94) for use in linear or circularly polarised systems. In one embodiment of the invention, a cross-type antenna feed (30) comprises a cylindrical metal waveguide housing (12) and a cross-type metal feed body (32) coupled to the front of the waveguide housing (12). The feed body (32) has four peripherally spaced corrugated arm portions (34) arranged in a mutually orthogonal relationship, where the arm portions (34) extend radially outwardly from a longitudinal axis (16) of the feed body (32). Ridges (36) on each arm portion (34) are arranged concentrically around the axis (16) and parallel thereto, with successive ridges spaced from the axis (16) in a tiered arrangement. In another embodiment the antenna feed is a dielectric lens. The antenna feed is used in an antenna system having a reflector antenna in addition or in a low noise block (LNB) receiver.

Abstract: An approach for providing a multiple-beam antenna system for receiving and transmitting electromagnetic signals from a plurality of closely spaced satellites is disclosed. Dielectric inserts are selectively coupled to the feedhorn bodies to alter the radiation patterns according to dielectric constants of the dielectric inserts. A reflector produces multiple antenna beams based upon the altered radiation patterns of the feedhorn bodies. The antenna provides simultaneous transmissions to satellites that are spaced about 2° or less.

Abstract: A flat plate or slab antenna (1) is fabricated from a number of sandwiched layers in which a number of arrayed individual antenna elements (3) are formed. The antenna elements (3) each include a horn (12) with a rectangular aperture (13) feeding (or fed by) individual rectangular waveguides (15). Two orthogonal probes (17,20) protrude into each waveguide (13), each of which is connected to respective beamforming networks. The network of first probes (17) operates at a first frequency while the network of second probes (20) operates at a frequency which is different from the first frequency. In the preferred embodiment, the edges (13) of the horn apertures (12) are parallel to the sides (6, 7, 8, 9) of the antenna slab while the walls of the rectangular waveguides are at 45° to the sides (6, 7, 8, 9) of the slab. The antenna (1) is able to receive and/or transmit two orthogonally linearly polarised signal at different frequencies and is therefore capable of full duplex operation.

Abstract: A feed horn structure in which a feed horn and a horn cap can be combined without generating whitening, crack and the like, a manufacturing method thereof, a converter having that feed horn structure, and a satellite communication receiving antenna can be obtained. The feed horn structure of a satellite communication receiving converter includes a cylindrical feed horn receiving a radio wave from an antenna portion and guiding the radio wave, and a horn cap fixed to the feed horn so as to surround one end of the feed horn at antenna side. The feed horn and the horn cap are integrated by integral molding.

Abstract: A method of laser machining using an ultra-fast pulse laser is presented. According to the present invention a plurality of holes with a pitch less than the wavelength of the laser are drilled into a material sample. Reliable and reproducible hole drilling is accomplished through an exemplary drilling sequence which applies a number of pulses at a first pulse energy to the surface spaced to avoid laser hardening of the surface for adjacent holes of a first set of holes. Next, the number of pulses is increased or the energy of the laser beam is increased to drill holes that are interstitial to the first set of holes. The exemplary laser machining process may used to produce both one-dimensional and two-dimensional photonic crystals, among other applications.

Abstract: An antenna feed in a satellite system that provides substantially equal E-plane and H-plane patterns. The feed includes outer and inner conductive walls that are coaxial, and define an outer waveguide therebetween and an inner waveguide within the inner conductive wall. The feed includes a first cylindrical waveguide section, a tapered waveguide section, and a second cylindrical waveguide section at the aperture of the feed. Downlink signals are in signal communication with the first cylindrical waveguide section so that the downlink signals are launched into the outer waveguide and out of the feed. Uplink signals received by the inner waveguide are directed to suitable uplink reception devices. One or both of the outer or inner conductive walls include an array of radially disposed iris pins at the aperture that interact with the uplink and/or downlink signals to provide beam symmetry or equal E-plane and H-plane patterns.

Abstract: A horn for direct radiation or for use as a reflector feed is for operation at disparate frequencies. The horn has a conventionally LSE1,0 distribution at the lower of the two frequencies, and both LSE1,0 and LSE3,0 modes, phased for improved gain, at the higher frequency. The LSE3,0 mode is generated by an H-plane step, and the appropriate phasing, together with improved gain at the lower operating frequency, is achieved by the use of dielectric loading adjacent the E-plane walls of the phasing section of the horn.

Abstract: A primary radiator includes a waveguide holding a dielectric feeder on which a radiation part, an impedance-conversion part, and a phase-conversion part are integrally formed. The radiator part widens from the aperture of the waveguide, and the phase-conversion part intersects a probe at an angle of substantially 45 degrees. Also, on the impedance-conversion part, a pair of curved surfaces are formed converging in the direction from the radiator part to the phase-conversion part, the impedance-conversion part has a cross-sectional shape which includes an approximately quadratic curve, and the thickness of the dielectric feeder converges such that the thickness gradually decreases in the direction from the radiator part to the phase-conversion part.

Abstract: An planar ultra wide bandwidth (UWB) antenna that provides integration of electronics is disclosed. The antenna has a first balance element that is connected to a terminal at one end. A second balance element is connected to another terminal at one end. The second balance element has a shape that mirrors the shape of the first balance element such that there is a symmetry plane where any point on the symmetry plane is equidistant to all mirror points on the first and second balance elements. Each of the balance elements is made of a generally conductive material. A triangular shaped ground element is situated between the first balance element and the second balance element with an axis of symmetry on the symmetry plane, and oriented such that the base of the triangle is towards the terminals. Accordingly, the ground element and each of the balance elements form two tapered gaps which widen and converge at the apex of the ground element as the taper extends outwardly from the terminals.

Abstract: Provided is an antenna apparatus including an antenna for receiving electromagnetic radiation from an object to be measured; and a condensing element, which is constructed to surround the antenna, which is located at a center of the condensing element, wherein the condensing element reflects and condenses the electromagnetic radiation toward the antenna. The antenna apparatus according to the present invention improves the gain and electromagnetic reception efficiency of the antenna and effectively reduces interference by external unwanted noise.

Abstract: The invention relates to an apparatus for transmitting radio-frequency signals using a signal generation unit (2), a signal line (3), a radiating element (4) and a waveguide (5) which is terminated in an end region by a back wall (6), where the signal generation unit (2) generates the radio-frequency signals, where the signal line (3) routes the radio-frequency signals to the radiating element (4), and where the radiating element (4) projects into the waveguide (5). The object is achieved by virtue of the radiating element (4) being arranged at an angle to the back wall (6) of the waveguide (5) or to a plane of the waveguide (5) which is parallel to the back wall (6).

Abstract: The present invention relates to antenna feeds (10, 30, 70, 78, 94) for use in linear or circularly polarized systems. In one embodiment of the invention, a cross-type antenna feed (30) comprises a cylindrical metal waveguide housing (12) and a cross-type metal feed body (32) coupled to the front of the waveguide housing (12). The feed body (32) has four peripherally spaced corrugated arm portions (34) arranged in a mutually orthogonal relationship, where the arm portions (34) extend radially outwardly from a longitudinal axis (16) of the feed body (32). Ridges (36) on each arm portion (34) are arranged concentrically around the axis (16) and parallel thereto, with successive ridges spaced from the axis (16) in a tiered arrangement. In another embodiment the antenna feed is a dielectric lens. The antenna feed is used in an antenna system having a reflector antenna in addition or in a low noise block (LNB) receiver.

Abstract: In a satellite broadcast reception converter, probes are equipped in a circular hole formed in a first circuit board, and plural fixing holes are formed around the circular hole. Snap pawls are formed at the open ends of the waveguides formed of sheet metal. The respective snap pawls are inserted in the fixing holes of the first circuit board so as to project to the back surface side of the first circuit board, and the fixing holes of the short caps are snapped into the snap pawls, whereby the first circuit board 6 is pinched and fixed between the waveguides and the short caps.

Abstract: Each of a first minute radiation pattern and a second minute radiation pattern is provided on a first circuit board so as to be inclined electrically by about 45° from the respective axial lines of a first probe for vertically polarized waves and a second probe for horizontally polarized waves. The first minute radiation pattern is approximately perpendicular to a phase conversion portion of a first dielectric feeder, and the second minute radiation pattern is approximately parallel with a phase conversion portion of a second dielectric feeder. The phase conversion portion of the first dielectric feeder is longer than that of the second dielectric feeder.

Abstract: A multiple mode feed horn is provided for transmitting and receiving signals. The feed horn includes a transverse electric throat section, a transverse electric profile section, and a transverse electric aperture section. The transverse electric profile section propagates a first transverse electric (TE) mode. The transverse electric aperture section propagates a second TE mode. The multiple mode feed horn prevents propagation of traverse magnetic modes from said throat section to said aperture section.

Abstract: A semi-coaxial horn antenna transmits and receives electromagnetic waves, including impulse radio waves. The antenna includes an inner conductor that is surrounded by a cone-shaped dielectric, and an outer conductor that is conformally attached to the cone shaped dielectric. In embodiments, the inner conductor is a hollow metallic cylinder that is able to slide over a separate metal shaft, which may be part of a portable hand-tool device. The dielectric constant of the cone shaped dielectric may be selected to match a target medium. The outer conductor has a cross-section that is substantially an arc shape, and defines a sector angle &phgr; that determines an impedance along the length of the antenna.

Abstract: A hog-horn antenna for producing two orthogonally polarized signals. The elevation plane pattern of each signal can be made to have virtually any shape, but is typically of a substantially cosecant-squared shape. In providing for the dual-polarization capability, the hog-horn antenna is designed to produce substantially equal gains for orthogonal polarizations, either simultaneously or separately. Two techniques to substantially equate the elevation plane radiation patterns of the two polarizations include corrugating or absorber-lining the surfaces of portions of the hog-horn antenna. Azimuthal pattern control may be achieved by corrugated/absorber lined flanges.

Abstract: An antenna apparatus that has an increased efficiency, and a method for increasing the efficiency of multi-mode antenna feed horns, is disclosed. The method comprises the steps of exciting, within the antenna, a desired transmission mode and an undesired transmission mode of the signal to be transmitted, and converting, within the antenna, power within the undesired transmission mode into power for the desired transmission mode of the signal to be transmitted. An antenna apparatus in accordance with the present invention comprises a feed horn having an input opening, an aperture, and a cavity, disposed between the input opening and the aperture, for suppressing an undesired transmission mode of the antenna and exciting a desired transmission mode of the antenna.

Abstract: A travelling waveguide antenna has top and bottom spaced plates, the top plate having radiating apertures extending therethrough. The apertures have inclined surfaces facing one another to provide an outward flare of the apertures.

Abstract: A dielectric plate is fixed inside a first waveguide, the inside of which is hollow, having a square opening at one end thereof, the dielectric plate is orthogonal to two parallel sides of the opening, a second waveguide having a square cross-section is connected to the other end of the first waveguide, and the dielectric plate is tilted by substantially 45° with respect to a pair of opposing internal wall surfaces of the second waveguide.

Abstract: Micro fabricated arrays of optical modulators of both a surface electrode and machined mesa nature where the small structure size and low capacitance electrical connections permit each modulator element to be individually electrically addressed thus providing modulator optical rise and fall response times in the low and sub nanosecond range. Both sparsely spaced and closely packed arrays are achieved.

Abstract: A side-mounting waveguide including a satellite down converter and a receiving horn antenna connected to the satellite down converter is characterized in that a circuit board of the satellite down converter is located at one side of the receiving horn antenna such that a transverse plane of the circuit board is in parallel with a direction in which the receiving horn antenna extends, and that a plastic rod is plugged into an opening of the receiving horn antenna to provide enhanced wave converging ability. With the side-mounting waveguide, the spacing between two adjacent satellite down converters and accordingly two adjacent receiving horn antennas is effectively reduced to correspond to the reduced angle contained between two satellites.

Abstract: A Ka-band horn for transmitting and receiving information between a ground station and a satelitte includes three sections. The throat segment of the horn is adapted for coupling to a feed and includes circular, alternating grooves and webs that are of a widening type created by linearly increasing the width of the grooves in the direction of the horn's aperture. The throat corrugations are for matching the impedance of adjacent sections of the horn. A middle segment includes an up-angle flare section and a down-angle flare section each having dual depth corrugations that enable the horn to achieve a near-HE11 mode at the aperture of the horn. The final segment of the horn is a truncated, smooth-walled, cone.

Abstract: A wave receiving apparatus comprising a reflector; a conduit for guiding waves, having an open end allowing entrance of polarized waves reflected by the reflector; a septum polarizer monolithically formed with the conduit for effecting a circular-linear polarization conversion; a pair of signal collectors pointing to the same direction or towards each other and positioned at a distance of quarter-wavelength away from the rear end of the conduit for receiving wave signals; and a circuitry module, positioned sidelong next to said conduit seen from said open end into said conduit, to which the signal collectors are electrically connected for handling wave signals.

Abstract: The invention relates to a Interactive Satellite Terminal antenna system comprising an antenna to which is associated a feed horn.

Abstract: A lens antenna including a lens body and/or a matching layer. In the lens antenna, lens body may be formed by a material containing thermoplastic elastomers. When a matching layer is formed on the surface of the lens body, at least one of the lens body and the matching layer is formed by a material containing thermoplastic elastomers. The use of thermoplastic elastomers in the lens body and/or the matching layer assist in reducing the formation of cracks therein.

Abstract: A high-isolation polarization diverse circular waveguide orthomode feed apparatus capable of supporting any arbitrary linear, right-hand circular, left-hand circular or elliptically polarized electromagnetic wave with desirable performance over a broad range of frequencies and small size is disclosed. The waveguide feed employs the combination of a circular waveguide segment, stepped septum polarizer, and a novel arrangement of diametrically opposed electric field probes in the bifurcated region of the circular waveguide segment to achieve low crosspolarization when operating in arbitrary linear mode and high-isolation for rejection of undesired cross-polarization components when operating in circular or elliptical polarization mode. This apparatus is an elegant, simple, compact, rugged, and cost effective design that is applicable to a broad family of microwave antennas, but in particular those required to meet minimal radome swept volume requirements.

Abstract: A satellite antenna system employing a dual-band feed horn and dual-band beam forming network. The feed horn provides a common aperture for both satellite uplink and downlink communications signal. The feed horn includes corrugations on an inside surface defining two sets of alternating channels having different depths to create circularly symmetric beams for the uplink and downlink signals. The antenna system includes at least one reflector, where the reflector shape, position, and the configuration of the feed horn, is determined so that the mainlobe of the lower frequency downlink feed signal illuminates the entire reflector, and the mainlobe of the higher frequency uplink feed signal illuminates an inner portion of the reflector. The first sidelobes of the higher frequency feed signal illuminate the outer portion of the reflector so that the uplink and downlink antenna signals have the same beamwidth, and thus cover the same cell size on the Earth.

Abstract: The present invention provides a primary radiator capable of achieving both loss reflection and low loss. A watertight cap made of a dielectric material having a relatively high dielectric constant is attached to an open end of a horn part continuing from a waveguide, a dielectric member made of a dielectric material having a lower dielectric loss than the watertight cap is disposed within the waveguide, and a projecting part integrally formed at an end of the dielectric member is extended to the inside of the horn part, whereby an end face of the projecting part is made to face the back of the watertight cap at a fixed interval.

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

Abstract: A horn for direct radiation or for use as a reflector feed is for operation at disparate frequencies. The horn has a conventionally LSE1,0 distribution at the lower of the two frequencies, and both LSE1,0 and LSE3,0 modes, phased for improved gain, at the higher frequency. The LSE3,0 mode is generated by an H-plane step, and the appropriate phasing, together with improved gain at the lower operating frequency, is achieved by the use of dielectric loading adjacent the E-plane walls of the phasing section of the horn.

Abstract: The horn (11) comprises a plurality of transition steps can also be provided to increase the control of amplitude and phase content of the TE11 and TM11 modes at the output of the corn horn mouth (17) and suppress the unwanted TE12 mode. This control of the mode content provides for minimizing the length of the multimode horn antenna for a desired aperture size at the desired operational bandwidth, and provide low sidelobes and low cross-polarization, over a relatively wide bandwidth, with high electrical efficiency.

Abstract: An antenna feed horn assembly includes a circular feed horn having an electrically conductive wall with an edge defining a circular aperture. The antenna feed horn assembly further includes a circular waveguide mounted to the base of the circular feed horn and including an endplate. An cylindrical rod extends from the center of the endplate towards the center of the feed horn aperture along a longitudinal axis of the antenna feed horn assembly to minimize undesired reflections produced by transitions between electrically conductive material and non-electrically conductive material or dielectric within the antenna feed horn assembly. An antenna feed horn assembly can also include a splash plate opposite the endplate, the center from which another cylindrical rod extends towards the center of the endplate along the longitudinal axis of the antenna feed horn assembly to further minimize undesired reflections.

Abstract: In a horn antenna apparatus for use in an antenna system for radar, some of the excited radio waves in a TE11 mode in a radio-wave input portion 1 are converted to those in a higher mode in a waveguide portion 5. As the inclination of a line of intersection S of the waveguide portion 5 is not fixed but continuously varied, the higher mode such as a TM11 mode and TE12 mode and the like is excited everywhere in the direction of the axis Z of the waveguide portion 5. Then the configuration of the line of intersection is determined so that an amplitude and a phase as the generated quantity of higher mode such as the TM11 mode generated in the waveguide portion 5 conform to desired values with respect to each higher mode.

Abstract: A diagonal dual-polarized broadband horn antenna. The unique use of diagonal line ridges placed in the corners of the aperture of the diagonal dual-polarized broadband horn antenna. The sides of the diagonal dual-polarized broadband horn antenna are made of any number of materials including dielectric material or metallic material. The operating frequency range of one embodiment of the present invention is approximately 100 MHz to 18 GHz in one embodiment. The present invention is scaleable to allow operation at even higher and lower frequencies. This ability of the present invention to adapt to a number of frequency ranges allows application for a wide variety of electromagnetic testing applications. The use of the diagonal line ridges allows for a broadband horn antenna that is significantly more manageable that conventional broadband horn antennas, while offering operation at common frequency ranges.

Abstract: A dual band, higher and lower frequency range transducer with a circular coaxial waveguide feed is described having a first junction for connection of a lower frequency range outer waveguide of the coaxial waveguide feed to at least two rectangular or ridge waveguides offset from the longitudinal axis of the transducer and a second junction for connection of the at least two rectangular or ridge waveguides to a further waveguide. A third junction is provided for connecting an inner waveguide of the coaxial waveguide feed to a higher frequency range waveguide. The transducer comprises at least first and second parts joined across a first plane substantially perpendicular to the longitudinal axis and including at least a portion of the higher frequency range waveguide extending within the first plane of the join. A seal such as an “O” ring seal may be placed easily in the plane of the join thus preventing moisture ingress.

Abstract: A family of FE dielectric-tuned antennas and a method for frequency tuning a wireless communications antenna are provided. The method comprises: forming a radiator; forming a dielectric with ferroelectric material proximate to the radiator; applying a voltage to the ferroelectric material; in response to applying the voltage, generating a dielectric constant; and, in response to the dielectric constant, communicating electromagnetic fields at a resonant frequency. Some aspects of the method further comprise: varying the applied voltage; and, modifying the resonant frequency in response to changes in the applied voltage. Modifying the resonant frequency includes forming an antenna with a variable operating frequency responsive to the applied voltage. Alternately stated, forming an antenna with a variable operating frequency includes forming an antenna with a predetermined fixed characteristic impedance, independent of the resonant frequency.

Abstract: An antenna system that employs antenna elements for both transmit and receive functions. Signals received by each antenna element are directed to a dual band polarizer that converts the signals to linearly polarized signals, and signals to be transmitted by each antenna element are converted to circularly polarized signals by the polarizer. The orientation of the polarizer and whether the circularly polarized signals are LHCP or RHCP determines whether the linearly polarized signals are vertically or horizontally polarized. A dual-band orthomode transducer is employed to separate the receive and transmit signals into their respective frequency bands based on whether they are vertically or horizontally polarized. The transducer is a waveguide device having only three signal ports. A high pass filter is used to help separate the received signals, and a low pass filter is used to help separate the transmit signals.

Abstract: An antenna system that employs an antenna element for both transmit and receive functions, where a dual band polarizer is used to convert linearly polarized signals to circularly polarized signals and vice versa for two frequency bands. The dual band polarizer includes a waveguide including corrugated structures extending from opposing sidewalls, where ridges in the structures extend perpendicular to the propagation direction of the signal. The height of the ridges taper from a lowest height at the ends of the waveguide to a largest height at the middle of the waveguide. The corrugated structures interact with the field components of the signal in the direction perpendicular to the ridges that cause that component to be delayed relative to the field components parallel to the ridges so that the signal changes accordingly and maintains the same magnitude.

Abstract: A multi-beam antenna includes a parabolic reflector, a block-down-converter, a support arm and a holding member. The block-down-converter is arranged such that a multi-primary radiator and a housing containing a conversion circuit are integrally molded. The multiprimary radiator is constituted by a plurality of primary radiators having apertures whose central points are arranged linearly. Neighboring two of the primary radiators are integrally joined with each other at a joint part. A polarization angle can be adjusted simply by a function that an angle formed between the block-down-converter and the support arm can be varied about a perpendicular radiation axis by the holding member. A feeding element pair formed on the conversion circuit is constituted by two feeding elements extending orthogonally to each other. Angles formed between the feeding elements and a central line of the joint part are determined on the basis of a center of a longitudinal range of a receiving area.

Abstract: A primary radiator including a waveguide formed by winding a metallic plate into a cylindrical shape and superimposing both ends thereof at a joining portion. Two first flat portions and two second flat portions, extending in the direction of the central axis of the waveguide, are formed so that a first flat portion and a second flat portion alternate at intervals of substantially 90 degrees, thereby forming a total of four flat portions. A dielectric feeder includes a radiator section, an impedance converting section, and a phase converting section.