Abstract: Systems and methods for two dimensional millimeter wave imaging are described. A system includes a spindle assembly defining a rotation axis; a waveguide assembly connected to the spindle assembly, the waveguide assembly including a first dielectric waveguide defining a first axis; and a grating assembly connected to the spindle assembly, the grating assembly including a plurality of sectors, each of the plurality of sectors including a varying period conductive grating pattern. A varying period of the varying period conductive grating pattern is a function of an angle defined by a rotational position of the grating assembly with regard to the rotation axis. The systems and methods provide advantages in that an image can be scanned quickly using an inexpensive system.

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 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 excitation system is indicated for an antenna with a parabolic reflector (1) and a dielectric radiator (3) which is attached to the end of a hollow conductor used to guide electromagnetic waves, and is located in the center of the reflector (1) and has a metallized end face designed as a subreflector. The reflector (1) is designed as a rectangular strip forming a sector antenna which has a parabolic curve in the direction of its long axis (A). The end face of the radiator (3) has four partial faces (8, 9, 10, 11) which form pairs and are arranged with respect to the central axis of the hollow waveguide (2) so that each pair of partial faces extends approximately at a right angle to the other pair of partial faces, the partial faces of each pair being of equal size. The two partial faces (8, 9) extending in the direction of the long axis of reflector (1) are large in relation to the two partial faces (10, 11) extending crosswise thereto.

Abstract: A planar array antenna having a switching matrix that couples an RF signal to two distributed ferrite scanning line feeds that feed a planar continuous transverse stub array antenna. The scanning line feeds couple RF energy to the antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. The antenna has reduced complexity and lower design and production costs. The use of dual ferrite scanning line feeds, the switching matrix, and the continuous transverse stub antenna to obtain wide-angle scanning provides significantly improved performance. The present invention uses the two distributed ferrite scanning line feeds to obtain greater scan coverage at upper millimeter-wave frequencies, where realizable ferrite materials are less active and provide diminished scan capability. The scanning line feeds and planar array antenna may be designed so that the four scan sectors are contiguous, to increase the angular scan coverage of the antenna.

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: Systems and methods for guided wave antennas are described. Apparatus is disclosed comprising: a dielectric nonphotoconductive waveguide defining a principle axis; a grating carrier connected to the dielectric nonphotoconductive waveguide, the grating carrier i) including a photoconductive material and ii) defining a photoconductive axis that is substantially parallel to the principle axis; a spatial light modulator optically connected to the layer of photoconductive material; and a source of illumination optically connected to the spatial light modulator and the layer of photoconductive material.

Abstract: A method for adjusting the radiation direction of an antenna, which uses a plurality of uniformly spaced diffraction gratings formed in the waveguide of the antenna while adjusting the maximum radiation direction of radiation waves emerging from the diffraction gratings and varying the length of crystal lattices in the diffraction gratings, thereby achieving an improvement in the directivity of the radiation waves and an adjustment in the radiation direction of radiation waves. In accordance with this method, it is possible to vary the radiation direction of an electronic wave passing through the antenna by varying the interval of crystal lattices in a region where the diffraction gratings exist. Accordingly, it is possible to obtain a narrow beam width characteristic. The diffraction gratings are made of a piezo-electric material.

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 waveguide antenna includes a number of longitudinal waveguides with lateral and longitudinal slots arranged to emit electromagnetic fields with separate directions of polarization. The waveguide antenna includes a first waveguide having a first rectangular cross-section with lateral slots at substantially right angles with respect to the longitudinal axis of the first waveguide. The lateral slots are arranged in a first short side of the first waveguide. The waveguide antenna also includes a second waveguide having a second rectangular cross-section with longitudinal slots arranged in a second short side at substantially right angles with respect to the lateral slots, and a separating wall. The first and second waveguides are joined at respective first and second broad sides with the first and second short sides facing the same direction.

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

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

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

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

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

Abstract: A low profile, compact microstrip-to-waveguide or stripline-to-waveguide transition. The end of the waveguide is terminated in a cavity backed slot defined in a groundplane formed on a dielectric substrate. The slot is excited by a microstrip or stripline conductor defined on the opposite side of the substrate. The conductor is terminated in a T-shaped junction including two opposed arms extending along the slot, each having a length equal to one-quarter wavelength at the center frequency of operation. A cavity covers the substrate on the conductor side, and is sized so that no cavity modes resonate in the frequency band of operation. The transition is matched by appropriate selection of the length of the slot and the length and position of the microstrip.

Abstract: A low profile, compact microstrip-to-waveguide transition which utilizes electromagnetic coupling instead of direct coupling. The end of the waveguide is terminated in a cavity backed slot defined in a groundplane formed on a dielectric substrate. The slot is excited by a microstrip line defined on the opposite side of the substrate, offset from the slot centerline. A cavity covers the substrate on the microstrip side, and is sized so that no cavity modes resonate in the frequency band of operation. The transition is matched by appropriate selection of the length of the slot and the length and position of the microstrip.

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

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

Abstract: A device for gauging the level of a fluid in a container includes a floating roof, a transmitter for feeding a first microwave signal downwards in the direction of a fluid surface of the fluid, and a receiver for receiving a reflected microwave signal. The device includes a collector located above and in the vicinity of the floating roof, collecting the first microwave signal producing a collected microwave signal. The device also includes a vertical wave guide passing through the floating roof. The vertical wave guide guides the collected microwave signal to the fluid surface, and receives a reflected microwave signal reflected from the fluid surface. The vertical wave guide then guides the reflected microwave signal back to the collector and further to the receiver. It is a special feature to permit accurate measurement of the level of the fluid surface without having direct access to the surface.

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

Abstract: A continuous transverse stub antenna array that comprises phase tuning sections disposed between adjacent stub elements. The antenna array includes a sheet of dielectric material having a plurality of transverse stub elements extending from a first surface thereof. A first metal layer is disposed on the first surface and side surfaces of each of the stub elements, and a second metal layer is disposed on a second surface of the sheet of dielectric material that forms a ground plane of the array. A plurality of tuning sections are formed in the sheet of dielectric material and are disposed between each of the stub elements that extend laterally across the sheet of dielectric material. The plurality of tuning sections have a cross sectional shape in the form of an inverted T. Each of the tuning section comprises a first parallel plate section comprising dielectric material, a first quarter-wavelength transformer section, a second parallel plate section that is partially filled with dielectric material.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A unitary waveguide element is employed in a light weight waveguide antenna. The waveguide element has a waveguide portion having a front wall with slots formed across it at predetermined locations, a continuous back wall, and substantially continuous broad walls. A first flange is formed on one of the broad walls lying in a plane that extends in the width direction. A pair of flanges are formed on the other broad wall that lie in planes that are displaced slightly from the first flange, so that when the waveguide element is superposed onto the next successive element, these flanges overlap with the second flanges straddling the first flange. The flanges are then bonded with epoxy or an equivalent agent. A rivet box is formed on the proximal side of the back wall and permits attachment of the waveguide element in precise alignment to a predrilled backing plate with rivets or other suitable fasteners. The rivets do not penetrate into the waveguide portion of the element.

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

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

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

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A hybrid antenna in which the flared end of a parallel plate of a transmion line is coupled to a frequency independent antenna so as to take the place of the higher frequency radiating portion of the antenna.

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

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

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

Abstract: An improved system for measuring dielectric properties of fluids in an oil well, utilizing the well casing as a waveguide for certain electromagnetic signals. A production logging tool in accordance with the invention includes a cylindrical mandrel sheathed by a housing. Transmitting and receiving coils are contained in annular grooves defined in the mandrel. In operation, the tool is suspended by a wireline logging cable within the casing of a producing well. The transmitting coils generate magnetic fields and azimuthal electric fields, which induce voltages in the receiving coils. These voltages are affected by the dielectric properties of fluids in the casing, and the voltages may be interpreted to determine dielectric properties such as water resistivity, dielectric permittivity, water hold-up, water cut, and water salinity.

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

Abstract: A unitary array of efficient directional corrugated feed horns, each having a desired corrugated horn cross-section within close tolerances, as well as accurate positioning and orientation relative to each other. The unitary array structure is comprised of a plurality of thin platelets which are laminated together in a selected sequence. The unitary array design provides a mechanical structure to support millimeter and sub-millimeter wavelength electronic devices for reception or transmission of electromagnetic energy and cooling fluid circulation channels within the array to remove unwanted heat generated by the attached electronic devices. The design of the present invention affords a relatively lightweight structure through removal of unneeded materials by forming cavities within the structure while leaving sufficient material for the bonding of the platelet assembly.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: An antenna having antenna modules for an extremely wideband active monopulse phased array system, the modules including a housing provided with four radiators of the rectangular open-ended waveguide type and with an electric circuit. With the antenna modules being suitably stacked, the radiators constitute a substantially continuous antenna surface, the radiators being positioned at the points of intersection of a system of equilateral triangles which make up the antenna surface. After preamplification, phase shift and down-conversion to an intermediate frequency, received signals from a large number of antenna modules are combined to yield a sum beam, an azimuth difference beam and an elevation difference beam.

Abstract: A method of fabricating a microwave waveguide component wherein a plurality of joinable thermoplastic members are first formed. The members, when joined, comprise a microwave waveguide component having an internal surface that is adapted to be plated. The thermoplastic members are then bonded together. Then, the internal surface is plated to form the finished microwave waveguide component. The present method forms microwave components from plated, injection molded thermoplastic and reaction injection molded thermosetting plastics. In particular, the plastic components made using the present invention exhibit comparable electrical performance, as measured by voltage standing wave ratio (VSWR) and insertion loss, decreased device weight and cost, and reliable and repeatable manufacturability when compared with devices formed using metals, conventional thermosetting plastics that have been metallized, and molded, plated and soldered thermoplastics.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common paralled plate structure in order to from a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A structure (20) coupling a microwave signal to a waveguide (30) is provided. Transmission walls (26) are supported in the waveguide to only partially surround a probe (22) extending longitudinally from the waveguide wall. The probe preferably terminates at one end in a transmit/receive portion (36) directed into the waveguide internal space and at the other end in a launch portion extending through either the waveguide endwall (24) or sidewall (28). The structure is particularly suited for economical fabrication.

Abstract: A microwave detector arranged in such a manner that a horn antenna element is fastened to the surface of a microstrip plate having a ground plate on its reverse side. The horn antenna element and the ground plate constitute a microwave receiving antenna so that the height of the microstrip plate is lowered. As a result, a compact microwave detector can be constituted.

Abstract: An antenna system for producing a millimeter wave beam having a Gaussian distribution uses a high power source and a partial mode converter operatively coupled to the source and reviving from the source a T.sub.m,n mode wave which might either be TE.sub.m,n or TM.sub.m,n'. The converter delivers a mixture of modes including the mode T.sub.m,n at a relative power rate of 70 to 85% and at a relative phase 0, and at least one of the following additional modes, namely T.sub.m,n-1 at a relative power rate of 10 to 20% and at relative phase .pi., and TE.sub.m,n+1 at a relative power rate of 10 to 20% and at relative phase .pi.. The mixture of modes is applied to a collimation reflector (3, 10), having a concentration point (5) constituting the antenna system outlet. The antenna system can convert any T.sub.m,n mode into a linearly polarized narrow beam of very high power (about 1 MW) and and of high frequencies above 100 GHz.

Abstract: Monolithic microwave integrated circuit (MMIC) technology is advantageously used to fabricate microwave circuitry for an antenna-converter system to enable an antenna and its associated converter circuits to be integrated together into a unitary package. Small reliable radio frequency (RF) circuits, polarization switch matrix circuits, intermediate frequency (IF) circuits and power and control circuits for the converter are manufactured and integrated onto a plurality of small area microwave circuit disks using MIC/MMIC technology. The plurality of converter circuit disks are sandwiched together and directly mounted flat against the back of the antenna to form a unitary package. The disks for the converter circuits are further sized such that the circuit disks fit within an envelope volume defined by the size and shape of the antenna.

Abstract: A mode converter for converting transverse electric modes into hybrid modes of type EH.sub.mn and including a circular waveguide provided with corrugations extending in a circumferential (azimuth) direction that become deeper toward its end and are continued in a subsequent helically outlined aperture antenna with constant depth. The emitted radiation is circularly polarized and, by the use of suitable reflectors for the emitted radiation, may be cause to be linearly polarized. The emitted radiation no longer has any sidelobes in the far field and its characteristic has a Gaussian profile over the azimuth angle.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A dual frequency band antenna (10) having frequency reuse capability. The antenna waveguide (12) includes a four port waveguide network which transmits and receives orthogonal, linearly polarized signals of each of two frequencies. A pyramidal horn (14) is engaged to the mouth of the waveguide, and a meanderline polarizer (16) is engaged to the aperture (17) of the horn (14) to convert the signals from linear polarizations to circular polarizations.