Abstract: An antenna having one-way circular polarization is of the type comprising a radiating element associated with a frequency filter. It comprises a polarization-selective device disposed at the transition between the frequency filter and polarizer means adapted to cause the wave to be circularly polarized. This multimode selective device is adapted 1) to enable the initial go mode to propagate, 2) in transmission, to pass one of the return modes induced by the polarizer means, and 3) to reflect the other return mode. At the polarizer, the wave made up of the initial mode and of the reflected return modes reinforces the circular polarization of the initial mode. Such an antenna can be made as a single piece of size and weight that are smaller than those of known antennas having one-way circular polarization.

Abstract: An ortho-mode transducer is disclosed having a common waveguide and two orthogonal port waveguides, each of which is also orthogonal to the common waveguide. Each port waveguide is coupled to the common waveguide with a coupling aperture which will pass signals having a particular polarity and cut off orthogonally polarized signals. The common waveguide is terminated in a shorting plane about one-quarter of the excepted signal wavelength from the vertical midpoint of the port waveguides. The short directs energy from the common waveguide into the port waveguides and directs energy from the port waveguides into the common waveguide.

Abstract: An antenna system for providing radiation over substantially 360.degree. in azimuth by illuminating a conical reflector with a radiation beam having a frequency distribution with a local minimum which is coincident with the point of the reflector thus avoiding scattering. Preferably the radiation intensity distribution is annular, most preferably being Laguerre-Gaussian in nature.

Abstract: A simple continuous metal pattern in a single plane is suspended in a waveguide filled with dielectric material. Two conductive pins penetrate the backshort of the waveguide in an axial direction and are connected at corresponding locations at opposite sides of the metal pattern. The metal pattern forms a radiating element in the shape of a continuous ring, having two convex (with reference to the central axis of the waveguide) primary antenna segments, each of which has one end joined to the corresponding end of the other segment by a narrow bridge segment. The opposite ends of the primary antenna segments extend generally away from each other and are joined by a narrow feedback segment. Within a desired frequency range of operation, the continuous metal pattern is excitable to produce both dominant orthogonal modes of circular polarization with the 90 degree phase difference and in both RHCP and LHCP orientation.

Abstract: An apparatus and associated method of manufacture for coupling a receiver and a transmitter to a single antenna feed horn so as to allow for the simultaneous transmission and reception of co-polarized signals, such as in a radio frequency communications system, are provided. To separate the two co-polarized signals of different frequencies, the apparatus comprises a waveguide junction, a first filter tuned to the transmit signal frequency, and a second filter tuned to the receive signal frequency. The apparatus may be manufactured using low-cost reusable-mandrel casting techniques.

Abstract: An improved dual gridded reflector antenna configuration which allows cross-polarization radiation to be scanned in any given direction. The dual-gridded reflector assembly includes a front parabolic reflector illuminated by a first source, and a second parabolic reflector illuminated by a second source. The second reflector is positioned adjacent to and behind the front reflector such that the center points of the reflectors align to define a center axis. Additionally, the first and second sources are positioned at different offsets with respect to the reflectors and have a respective rotated offset angle with respect to the center axis such that the sources define an antenna feed separation. By modifying the offsets and the rotated offset angles, the feed separation can be designed to have an inclination with respect to the north-south or east-west feed separation direction.

Abstract: A radiating element for an antenna incorporating a patch launcher, a bandpass filter and a polarizer all in one waveguide without the need for interconnecting individual components. The waveguide has at least one coaxial input having a patch launcher attached thereto. The inside diameter of the waveguide has a plurality of spaced apart irises that act as a bandpass filter followed by a plurality of spaced apart pins that act as a polarizer.

Abstract: A waveguide input apparatus of two orthogonally polarized waves includes a waveguide having two cavities passing through the outer wall thereof to the interior, a first probe provided protruding from an inner wall of the waveguide via a first cavity so that the leading end is parallel to a first plane of polarization, a second probe provided protruding from the inner wall of the waveguide via a second cavity so that the leading end is parallel to a second plane of polarization, and a circuit board provided at the outer wall of the waveguide so as to be parallel to the second plane of polarization, and having the first probe and the second probe connected thereto. A converter for satellite broadcasting receiver employing this apparatus is also provided.

Abstract: A light weight parallel plate polarizer (100) employs a sandwich construction design including a polarizer section (102) and a foundation section (104). The polarizer section (102) is formed from low dielectric constant, low density foam or honeycomb layers (112) alternating with polarizer panels (110). The foundation section (104), which supports the polarizer section (102), is formed from a low density, low dielectric constant foundation material. In an alternate embodiment of the present invention, the light weight parallel plate polarizer employs a suspension design (400). The suspension design (400) includes individual sections of dielectric mesh (602) which support polarizer plates (402). The individual mesh sections (602) are suspended between first and second support posts (404, 406) and compression springs (410) may be provided for adjusting and maintaining the tension in the mesh sections (602).

Abstract: Shaped beam antenna, with single or double reflector, gridded or non-gridded, the shaped beams, which can rotate the polarisation, independent of the polarisation of the feed cluster, for use preferably aboard satellites and in micro-wave antennas. The antenna includes a reflector (1), one or more polarisers (2), (2a), one or more feed clusters (3), (3a) , microwave circuits (4), (4a) to set-up the BFN, input port (5), (5a), and connections (C) and (C1).

Abstract: A common aperture, dual mode semi-active laser (SAL) and millimeter wave (MMW) sensor having transreflector configured to allow transmission of SAL energy therethrough, a separator and a fresnel lens configured to pass MMW energy therethrough and to focus SAL energy passing therethrough, the separator being configured to separate SAL energy from MMW energy, and a twist reflector positioned in alignment with the transreflector, configured to rotate the polarization of the MMW energy such that, for received MMW energy, the twist reflector reflects and rotates the received MMW energy toward the transreflector, which reflects it onto a feed and comparator, and for transmitted MMW energy, the transreflector reflects toward the twist reflector, whereupon polarization of the transmitted MMW energy is rotated and reflected therefrom to then pass through the transreflector.

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: A dual polarized antenna comprises at least one radiating element and a ground plane. The ground plane is, at least partly, provided with a side wall. At least one polarization selective element is provided between the radiating element and the side wall to transmit one of the polarizations and to determine the radiation pattern of the other polarization.

Abstract: A frequency selective medium that is adapted to receive an incident electromagnetic radiation at an angle of incidence of about 45.degree. has two arrays of conductive elements on opposite parallel surfaces (20, 22) of a dielectric substrate. In one embodiment, the conductive elements are cross-dipoles (6) each having a horizontal dipole (10) and a vertical dipole (8) of different lengths and widths. In another embodiment, the conductive elements comprise a plurality of conductive gridded rectangular loops (40). The frequency selective medium allows incident waves that are within a passband of transmit frequencies to transmit through the medium, and reflects waves at frequencies within a stopband adjacent the passband. In other embodiments, meanderline polarizers (28) are added to cross-dipole and gridded rectangular loop frequency selective media to circularly or dual-linearly polarize incident linearly polarized waves.

Abstract: The radiation directivity of radio waves can be controlled more easily over a wider range by using the disclosed dielectric lens. A dielectric lens element having a curved surface is bonded to one of the surfaces of a laminate element in the shape of a flat plate in which a plurality of dielectric layers whose relative dielectric constants are different for adjacent layers are laminated. By controlling the distribution mode of the relative dielectric constants in the laminate element, the radiation directivity for the entire dielectric lens apparatus can be controlled; therefore, the radiation directivity can be controlled more easily over a wider range. A focal point may be positioned within or at the surface of the laminate element, and a signal processing circuit may be formed within and/or at the surface of the laminate element.

Abstract: A dual frequency feed element for a parabolic reflector antenna system, comprising a conductive cavity having a central axis, the cavity mounted at the focal point of a parabolic reflector surface and defined about its outer perimeter by an upstanding cavity wall, and having a closed cavity floor and an open top directed toward the reflective surface, a dual frequency radiating element centrally disposed in the cavity and arranged to radiate a first low frequency signal out through the cavity open top to the antenna surface, a conductive floor fixed below the radiating element a distance in relation to the radiant energy for the first low frequency signal, and disposed in the cavity transverse to the central axis thereof to reflect radiant energy for the first signal and, a frequency selective surface fixed below the radiating element, apart from the conductive floor, and transverse to the central axis of the cavity to reflect radiant energy for the second, higher frequency signal while simultaneously being i

Abstract: A wideband lens antenna lens of reduced thickness includes a lens antenna constructed of a flat inhomogeneous dielectric plate. A radiation source is located on one side of the dielectric plate and a reflector is located on another side of the dielectric plate opposite the radiation source. In operation, signals generated by the radiation source of arbitrary polarization pass through the dielectric plate, are reflected by the reflector, and pass back through the dielectric plate a second time before being emitted from the lens antenna. In such a case, the provision of the reflector allows the thickness of the dielectric plate to be cut in half as compared with conventional lens antennas. If the signals supplied by the radiation source are linearly polarized, a polarization transformer is provided on the same surface of the dielectric plate as the radiation source.

Abstract: A communication and tracking antenna is formed by embedding a tracking patch array in a shaped dual gridded reflector. The reflector includes first and second reflector grids that have orthogonally arranged grid lines and are respectively fed by feed horns. The patch array is positioned so that the first reflector grid is between the patch array and the first feed horn. The first reflector grid thus serves as a filter to remove unwanted polarization components and enhance the quality of both the tracking radiation and the radiation that is reflected from the second reflector grid. In other embodiments, a tracking array is positioned adjacent a reflector's perimeter.

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 radiation sensor for the microwave and millimeter-wave regions incorporates a lens having two parallel focal planes, these being defined by a polarization-selective reflector grid within the lens. One focal plane is occupied by a receive array of crossed dipole antennas with respective mixer diodes. One dipole of each antenna couples to a local oscillator signal and the other couples to a receive signal reflected by the grid. These signals are mixed by the diodes to produce intermediate frequency signals for subsequent processing. The other focal plane is occupied by a transmit array of separately activatable polarization switching antennas arranged to define a range of transmit beam directions. This focal plane may alternatively be occupied by a second receive array.

Abstract: An improved flatplate array antenna has a polarizer lens positioned adjacent the array. The polarizer lens is made of at least one dielectric sheet having an upper half and a lower half. Each half contains a set of parallel meanderlines positioned so that vertically or horizontally polarized RF energy emitted from the array passes through the lens and undergoes a phase advance or a phase retard, so that the RF energy passing through the upper half becomes circularly polarized in one direction and the RF energy passing through the lower half becomes circularly polarized in an opposite direction.

Abstract: An interleaved planar array antenna system providing opposite circular polarizations comprises an array of parallel rows of parallel spaced transmit dipole radiating elements and an array of parallel rows of parallel spaced receive dipole radiating elements. Both sets of dipole elements are on the same surface, with the receive dipole elements being oriented orthogonal to the transmit dipole elements and the rows of transmit and receive elements being interleaved. On another surface parallel to and spaced from the first surface, there is at least one transmit feed line which is proximity coupled to the transmit dipole elements and at least one receive feed line which is proximity coupled to the receive dipole elements. Polarizing means are spaced from and overly the transmit and receive dipole elements for transforming orthogonally oriented linearly polarized transmit and receive beams into oppositely circularly polarized transmit and receive beams.

Abstract: A description follows of a circuit arrangement for selectively processing a first or a second high-frequency signal, which guarantees a proper broadband separation of the high-frequency signals comprisinga first inserting device for inserting the first high-frequency signal from a common waveguide arrangement into a first signal processing branch, a second inserting device for inserting the second high-frequency signal from the common waveguide arrangement into a second signal processing branch, a switchable high-frequency amplifying arrangement in each signal processing branch for selectively switching and amplifying, and blocking respectively, the associated inserted high-frequency signal, anda transmission arrangement in each signal processing branch for transmitting the associated high-frequency signal from the first or second respectively, inserting device to the associated, switchable high-frequency amplifying arrangement, in which each of the transmission arrangements comprises a high-frequency preampl

Abstract: A linear-circular polarizer used for the transmission in the microwave band, which provides excellent impedance characteristics and stabilized cross polarization characteristics by having 1/4 wavelength phase plates and the inner surface of a circular waveguide made in one-piece for the purpose of cost and production step reduction. The linear-circular polarizer includes a pair of 1/4 wavelength phase plates of a specified width and height formed opposite to each other and symmetric with respect to the waveguides central axis. The 1/4 wavelength phase plates are formed on the inner surface of a circular waveguide at a closed end opposite to an end where a primary radiator is located.

Abstract: A dielectric filter includes a dielectric block on which an external conductor is formed except for areas surrounding input and output terminals, a plurality of resonator holes of the same axial length, and input and output external coupling bores. The resonator holes and input and output external coupling bores are formed substantially in parallel with each other between a pair of opposing end faces of the dielectric block. The resonator holes are provided with internal conductors except for dielectric bases in the vicinity of openings thereof. The internal conductors are connected to the external conductor at the pair of end faces so that resonators having specific resonator lengths are constituted by the positions of open ends thereof formed by the dielectric bases. The input and output external coupling bores are provided with internal conductors.

Abstract: A pair of dual-gridded shaped reflectors (10) and (20) are arranged one behind the other for transmitting and receiving orthogonally polarized energy waves. A front reflector (10) has a first shaped reflective surface (12) formed on a first body surface (14) for providing a first shaped beam coverage. A rear reflector (20) has a second reflective surface (22) formed on a second body surface (24) for providing a second shaped beam coverage. The first and second reflective surfaces (12) and (22) have substantially identical surface contours and include reflective grids (13) and (23). The reflective grids (13) and (23) are orthogonal with respect to each other so as to handle orthogonally polarized energy. The first and second shaped reflective surfaces (12) and (22) are arranged offset and tandem from each other so as to provide first and second focal points (16) and (26) separate from each other while providing substantially identical first and second shaped beam coverages (15) and (25).

Abstract: An electronically-scanned two-beam antenna designed for being installed on board a moving platform, and in particular a satellite. The antenna of the invention comprises a single, complex reflector whose reflectivity is responsive to the polarization with which it is illuminated, and associated with two arrays of orthogonally-polarized sources that illuminate the complex reflector using an offset configuration. The complex reflector is made up of two reflectors placed one in front of the other in the beam propagation direction. The first reflector is transparent to a first linear polarization and reflective to an orthogonal polarization, while the second reflector is reflective at least for the first polarization. The two resulting beams thus propagate in different directions, both parallel to the trajectory of the platform. Electronic scanning is provided in a plane perpendicular to the orbit plane.

Abstract: A low-noise-block downconverter (LNB) for use with flat antennas receiving dual polarized electromagnetic waves includes a body case mounted to a rear side surface of the flat antenna, the body case having two wave guide input ports corresponding to wave guide apertures of the antenna and enclosing a selective device alternatively allowing either one of two outputs corresponding to two different type polarized electromagnetic waves received.

Abstract: A dual polarisation waveguide probe system for use with a satellite dish (10) for receiving satellite signals orthogonally polarised in the same frequency band and for providing improved isolation between these polarised satellite signals is disclosed. The probe system has a waveguide (28) incorporated in a low-noise block receiver (12) into which two probes (34, 38) are located for receiving linearly polarised energy of both orthogonal senses. The probes (34, 38) are located in the same longitudinal plane on opposite sides of a single cylindrical bar reflector (36) which reflects one sense of polarisation and passes the orthogonal signal with minimal insertion loss, and then reflects the rotated orthogonal signal. The probes (34, 38) are spaced .lambda./4 from the reflector (36). A reflection rotator (44) is also formed using a thin plate which is orientated at 45.degree. to the incident linear polarisation with a short circuit (46) spaced approximately a quarter wavelength (.lambda.

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 microwave lens of the type described in the French patent No. 2,469,808 is adapted to operate with two crossed polarizations. To this end, each of the phase-shifting channels of the lens is subdivided into two subchannels, each of them being assigned to one of said polarizations. Each subchannel includes, in addition to phase-shifting panels, means for rotating by 90.degree. the polarization of the incident wave and impedance matching means.

Abstract: A low profile slot antenna is provided which includes first and second oppositely disposed metallic plates with a dielectric layer disposed therebetween. An array of horizontal and vertical radiating elements are formed in the first metallic plate. An array of horizontal coupling slots and an array of vertical coupling slots are formed in the second metallic plate. The antenna further includes a planar feed network electrically coupled to the coupling slots. The feed network is connected to a conductive waveguide tube located at the central portion of the antenna. Orthogonal probes couple the waveguide tube to a transceiver. Accordingly, the slot antenna may operate to transmit and receive linearly polarized energy. The antenna may further include a polarization converter for converting between linear and circular polarization so as to allow for antenna operation with single or dual circular polarization energy.

Abstract: A reflector antenna assembly for dual linear polarization includes at least two feeds and two reflectors. At least one reflector has a surface which is nominally electrically transparent to linearly polarized radiation in one direction and is located in front of the other reflector so as to be closer to said feeds. At least one of the reflectors is profiled in a manner such as to enable it to generate at least one complex contoured beam while using one of said feeds.

Abstract: The invention pertains to an electronic sweep device with integrated active lens and light source.The device includes a bundling of superimposed channels C which are separated by thin metal planes P that include, in front of a metal short-circuit plane (10), illumination organs (S) and phase displacement organs (B).The invention makes it possible to create a compact electronic sweep device which eliminates the parasitic reflection phenomena between illuminator and lens for the purpose of controlling a hyperfrequency beam.

Abstract: Electronically adaptable polarization antenna feed apparatus for receiving any sense of linear polarization or for receiving either sense of circular polarization. The circuit makes use of variable gain amplifiers and/or variable attenuators in each of two orthogonally polarized paths. The signal to noise ratio of a desired polarization sense is maximized by adjusting the amplitude or gain in each path to a desired ratio. If desired, polarization components from the two probes may be combined so that orthogonal polarization senses from two frequency reuse signals be used simultaneously. The apparatus may be used with linearly polarized signals and with circularly polarized signals.

Abstract: Antenna elements and systems and other radio and microwave frequency devices are constructed with a high index of refraction medium having high matched values of relative permeability and relative permittivity, and a low loss tangent. By making the permeability of the transmission medium substantially equal to its relative permittivity, the impedance of the material is matched to that of the surrounding free space or air. By immersing a radiating element in such a material, and/or by using such a material between adjacent radiating elements or between a radiating element and a reflective ground plane, the physical size and/or the spacing of the elements may be substantially reduced without appreciable performance loss, thereby resulting in a more compact device that is particularly desirable for mobile applications.

Abstract: A satellite-based cellular telecommunications system employing a constellation of telecommunications satellites in medium earth orbit to provide multibeam radio frequency (rf) communications links for worldwide cellular telephone service with a minimum number of satellites. The telecommunications satellites are placed in a plurality of inclined orbits about the earth at an altitude of between approximately 5600 and 10,000 nautical miles. The characteristics of the orbits, such as the number of orbits, the inclination of each orbit, the number of satellites in each orbit and the altitude of the satellites, are tailored to maximize the coverage area of the satellites and their related line-of-sight elevation angles, while minimizing propagation time delays, the number of beam-to-beam and satellite-to-satellites handovers, and the total number of satellites.

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 dual-polarized antenna includes a planar line or surface array of reradiating elements of two different polarizations. Each reradiating element in one embodiment is a short-circuited vertical or horizontal dipole. The vertical and horizontal dipoles may be collocated on the array to form crossed short-circuited dipoles. The elements of each polarization form an array separate from the elements of the other polarization. Within each of the two separate arrays, the 1/.lambda. of each reradiator is adjusted to provide a phase shift which causes a collimated beam incident on the array to result in reradiation or "reflection" of energy in the form of a beam converging at a focal point. Therefore, each planar reradiator array acts as a parabolic reflector with a particular focal point. The focal points for the vertical and horizontal arrays are different, and a feed of the appropriate polarization is located at each of the two focal points.

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 planar antenna in multilayered arrangement of a grounding conductor plate, a power supplying circuit plate and a radiating circuit plate being separated from one another. Radiating elements of the radiating circuit plate are a plurality of apertures electromagnetically coupled to power supply probes of the power supplying circuit plate. On the radiating circuit plate, a polarizer capable of converting linear polarized waves into circular polarized waves is provided, whereby the antenna is enabled to ensure a high efficiency and wide-band cross polarization characteristics.

Abstract: An antenna for transmitting rf energy. A polarizer for selectively polarizing the rf energy is operatively connected to a longitudinal shunt slotted plate for radiating rf energy therethrough. A rotational series slotted plate is operatively connected to the longitudinal shunt slotted plate for feeding the rf energy thereto. The plate has slots arranged in columns. First and second dual end slot array feeds are operatively connected to first and second columns of series slots of the rotational series slotted plate, said feeds having first and second input tee junctions. A manifold is operatively connected to the first and second input tee junctions for feeding the rf energy to first and second columns of the slots, the first and second columns of slots having, respectively, n1 and n2 numbers of slots with n1>n2. The manifold includes a power divider, and first and second waveguide lengths connected to the power divider for receiving rf energy.

Abstract: A slot antenna is provided which includes first and second oppositely disposed metallic plates with a dielectric layer disposed therebetween. An array of horizontal and vertical radiating elements are formed on the first metallic plate. An array of horizontal coupling slots and an array of vertical coupling slots are formed in the second metallic plate. The antenna further includes first and second beam formers for providing a necessary field of view beam coverage. The array of horizontal coupling slots are operatively coupled to the first beam former and the array of vertical coupling slots are operatively coupled to the second beam former. Accordingly, the slot antenna may operate to transmit and receive linearly polarized energy. The antenna may further include a polarizer disposed above the upper metallic plate for converting between linear and circular polarization so as to allow for antenna operation with single or dual circular polarization energy.

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: An array antenna includes a means of thermally isolating the feed network from the space illuminated by the antenna. Filtering layers are incorporated into the structure between the feed and the radiating patches. These filtering layers are transparent to radiation in the frequency range of operation of the antenna, primarily microwaves and millimeter waves, but reflect much shorter wavelengths such as infrared and visible light. This rejection of short wavelengths results in reduced heating of the feed network and so to a reduced heat load on a cooling system. One preferred embodiment employs the radiation shield to advantage by incorporating superconductive elements in the antenna. These elements can be cooled efficiently enough to be practical due to the rejection of heat by the incorporated filtering layers.

Abstract: A planar antenna includes a set of first radiating plate and first power supplying plate in which openings of the former and power supplying terminals of the latter are respectively coupled electromagnetically to each other, and a further set of second radiating plate and second power supplying plate in which openings of the former and power supplying terminals of the latter are respectively coupled electromagnetically to each other. Antenna structure is thereby simplified while improving productivity and wide band wave reception, and allowing two different polarized waves to be received.

Abstract: An electromagnetic radiation converter for receiving and converting microwave signals having a circular or linear polarization. The converter comprises a waveguide for transmitting both circularly and linearly polarized signals, and a first mode transducer for converting the vertical component of the microwave signal into a corresponding signal on a microstrip line, a second mode transducer for converting the horizontal component of the microwave signal into a corresponding signal on a microstrip line, and means for combining the outputs of the first and second transducers. When receiving a circularly polarized signal, the combination means adjusts the phase of the vertical and horizontal components of a circularly polarized signal such that the phase of the vertical and horizontal components are equal prior to being combined so as to produce a signal equivalent to the circularly polarized signal originally received.

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: The usable range of incidence angles for electromagnetic wave polarizers using arrays of polarizer elements is increased by introduction of a dielectric medium having a dielectric constant large enough to reduce the angle of wave incidence upon the polarizer elements. For example, arrays of 45 degree inclined meander-line polarizer elements are encased in a dielectric medium having a dielectric constant of about 3. The polarizer includes impedance matching layers at the surfaces of the dielectric medium to reduce reflections at those surfaces. The resulting polarizer is indicated to be usable to reciprocally convert an incident polarization to a desired polarization (e.g., from linear to circular polarization) for waves with incidence angles from zero to 70 degrees in any plane.

Abstract: Antenna elements and systems and other radio and microwave frequency devices are constructed with a high index of refraction medium having high matched values of relative permeability and relative permittivity, and a low loss tangent. By making the permeability of the transmission medium substantially equal to its relative permittivity, the impedance of the material is matched to that of the surrounding free space or air. By immersing a radiating element in such a material, and/or by using such a material between adjacent radiating elements or between a radiating element and a reflective ground plane, the physical size and/or the spacing of the elements may be substantially reduced without appreciable performance loss, thereby resulting in a more compact device that is particularly desirable for mobile applications.