Abstract: A primary radiator has a dielectric feeder at an open end of a waveguide in which the total length of the dielectric feeder is reduced. The dielectric feeder includes a holding portion forced into the interior of the open end portion of the wave guide and a radiation portion protruding outwardly from the open end of the wave guide, at least one recess being formed in each end surface of the two portions. The recess includes a stepped hole composed of a large diameter cylindrical hole and a small diameter cylindrical hole connected to the bottom surface thereof, the depth of each cylindrical hole being approximately ¼ of the wavelength &lgr;&egr; of the radio wave propagated through the dielectric feeder.

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: An antenna apparatus and method for building the antenna is disclosed. Impulse signals travel through a feed point of the antenna with respect to a ground plane. A geometric fin structure is connected to the feed point, and through a termination resistance to the ground plane. A geometric ridge structure connected to the ground is positioned with respect to the fin in order to receive and radiate electromagnetic energy from the impulse signal at a predetermined impedance and over a predetermined set of frequencies. The fin and ridge can be either a wire or a planar surface. The fin and ridge may be disposed within a radiation cavity such as a horn. The radiation cavity is constructed of stamped and etched metal sheets bent and then soldered together. The fin and ridge are also formed from metal sheets or wires. The fin is attached to the feed point and then to the cavity through a termination resistance.

Abstract: A dielectric feeder has a holding portion inserted into the interior of a waveguide and a horn-shaped radiating portion having different radiation angles in major- and minor-axis directions. A plurality of annular grooves each having a depth corresponding to about a quarter wavelength of a radio wavelength &lgr;0 is formed in an end face of the radiating portion. An outer peripheral surface of the holding portion is cut out at circumferentially opposed positions axially in parallel with each other to form a pair of flat surfaces. Both flat surfaces are positioned in the major axis directions of the radiating portion and are thereby allowed to function as a phase compensating portion for compensating a propagative phase difference induced in the radiating portion. Further, there is formed a stepped hole comprising two recesses which are contiguous to each other from an end face of the holding portion toward the interior of the holding portion.

Abstract: In a primary radiator, a dielectric plate is fixed to the interior of a hollow first waveguide having, at one end, an opening shaped like a regular square, and is substantially orthogonal to two parallel sides of the opening. A second waveguide of rectangular cross section is coaxially connected to the other end of the first waveguide. A pair of probes are disposed at an angle of approximately 45° with respect to the dielectric plate so as to protrude from flat inner wall surfaces of the second waveguide toward the center axis.

Abstract: A microwave radiating element including first and second means for conveying electromagnetic waves in respective first and second frequency bands, wherein the first and second means are coaxial.

Abstract: A multimode horn used to feed an antenna includes a generally hollowed conical structure for transmitting and/or receiving an electromagnetic signal there through. The structure flaring radially outwardly from a throat section to an aperture has a pre-determined size and an internal wall with a plurality of discontinuities for altering the mode content of the signal to achieve a balance between a plurality of performance parameters of the antenna over a pre-determined frequency range of the signal. At least one performance parameter is from the group of horn on-axis directivity, horn pattern beamwidth, antenna illumination edge-taper, antenna illumination profile and antenna spill-over losses. The discontinuities are a combination of different local smooth profiles and/or steps and/or corrugations and/or chokes.

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 millimeter or submillimeter wavelength device including a substrate (2) having a horn shaped cavity (18), and first and second extension layers formed on a top surface of the substrate adjacent to the horn shaped cavity. The first and second extension layers define additional opposed sides of the horn shaped cavity, channels, and walls of the waveguide. Internal surfaces of the horn shaped cavity, the channels, and the waveguide walls include a conductive layer. Two such structures, which are mirror images of each other, are joined to form a horn antenna with integrated channels and a waveguide. The device is fabricated by forming a resist layer on a substrate which includes a horn shaped cavity. The resist layer is etched to form a half horn antenna, channels and walls of a waveguide. Internal surfaces of the half horn antenna, the channels, and the walls of the waveguide are then metalized. Two such metalized structures are then joined to form a full horn antenna integrated with channels and a waveguide.

Abstract: A sector beam antenna with a scattering component, in which a desired radiation pattern can be obtained, is provided. The sector beam antenna with the scattering component provides parallel plates composed of two conductive plates disposed in parallel in which the distance between the parallel plates is longer than a half wavelength and shorter than one wavelength of a using wavelength, a primary radiator block having an H bend function disposed between the parallel plates, an input port opened at one of the parallel plates in order to supply power to the primary radiator block, and a scattering component made of a conductive material and disposed in parallel to an aperture being an opening end of the parallel plates in a state that a designated distance exists between the scattering component and the aperture. With this structure, the radiation pattern radiating from the aperture can be formed freely.

Abstract: A feed horn comprises a waveguide having an opening portion of a circular section and a horn portion having an elliptic open end and connected to the waveguide. On an inner slant peripheral surface of the horn portion are formed a plurality of elliptic grooves at radial intervals axially from a front end of the horn portion toward the waveguide, as well as a plurality of axially extending elliptic ridges partitioned by the grooves. Tip ends of the ridges are formed with a difference in height so as to approach the waveguide successively as they are positioned radially centrally. The horn portion has an elliptic tapered portion which expands in a horn shape from one axial end of the horn portion toward a front end of the elliptic open end, namely, the axial front end of the horn portion.

Abstract: An antenna, or in the context of an array an antenna element, includes a feed and a separate polarization converting director. The polarization converting director includes a helically disposed conductor defining a pitch, a projected diameter, and a longitudinal axis. The feed propagates electromagnetic radiation (in transmit mode) toward the director, parallel its axis. The director intercepts part of the radiation, focuses or directs the radiation, and also converts circular polarization to linear, or linear polarization to circular. The feed may thus be linearly or circularly polarized. Various feeds include waveguides or horns, slots, dipoles, and planar or nonplanar spirals.

Abstract: In a high-voltage installation having at metallic encapsulating housing, a cone antenna is provided as a device for transmitting electromagnetic signals. The cone tip antenna facing the inner wall of the encapsulating housing resulting in an optimal coupling characteristic.

Abstract: The present invention provides various wave-guides and support structures that are used in conjunction with feed structures to form compact antennas. Specifically, in one embodiment, the present invention provides a wave-guide design used for connecting the feed of an antenna to various electronics, such as a transmitter or receiver. The wave-guide of this embodiment includes a first end for connecting to the feed and a second end for connection to either a transmitter, receiver, or other electronic components. Importantly, the body of the wave-guide extends in a direction towards the reflector of the antenna so that the second end of the wave-guide is positioned closer to the reflector than the first end of the wave guide. As such, the transmitter or receiver that is connected to the second end of the wave-guide is located in close relationship with the reflector, thereby creating a compact, aesthetically pleasing antenna structure.

Abstract: A radiation section of a dielectric feeder protrudes from an opening of a waveguide to improve the efficiency of receiving radio signals. An opening is provided at one end of the waveguide. A dielectric feeder held within the waveguide has a radiation section protruding from the opening. An annular wall having a bottom surrounds the opening of the waveguide. The depth of the annular wall is about ¼ of the wavelength of radio waves, and the width of a bottom surface of the annular wall is about ⅙ to {fraction (1/10)} of the wavelength of the radio waves. Consequently, the phases of a surface current that flows from the opening toward the bottom surface of the annular wall and a surface current which flows from the bottom surface of the annular wall toward the open end are substantially out of phase. As a result, the side lobes of the received radio signals are greatly reduced, and the gain of the main lobe is increased, improving the reception of radio waves transmitted from a satellite.

Abstract: The present invention provides a miniaturized circular polarized microstrip antenna that employs a dielectric substrate having a large relative dielectric constant so that a desired resonance frequency and a desired axis ratio are obtained. In a circular polarized wave microstrip antenna 1 having a nearly square dielectric substrate 4 with a nearly square patch electrode 2 formed on one surface thereof, and a ground electrode 3 formed on almost the whole of another surface thereof, triangular first notches 2a and 2b serving as retraction-separation elements are respectively formed 135 and 315 degrees with respect to a direction toward a feeding point 5 from the center of the patch electrode 2, which is defined as 0, and within the first notch 2b, a first adjustment electrode 2c extending outwardly from an edge of the patch electrode 2 is formed.

Abstract: An antenna structure for the transmission and processing of electromagnetic microwave signals is manufactured by making holes in a number of electrically-conductive plates by a mechanical or chemical process in order to create cut-outs in the form of through holes with electrically-conductive edge surfaces. For each plate, the holes have a defined position and length from one side of each plate to its other side. The plates with the holes are stacked in a defined relative position, and the sides of the plates are fixed to each other at least around the edge surfaces formed. In this way, a number of holes are given electrically-conductively limited surfaces in the form of the edge surfaces and also the parts of the side surfaces of the surrounding plate facing the holes.

Abstract: A monopulse antenna apparatus and antenna structure comprising a single horn having four dielectric bars which are internally inserted into the horn and symmetrically positioned along the axis of the horn. Each one end of the bars are fixed to the end wall of a rectangular waveguide and the other end is extending outwardly along the axis of the rectangular waveguide, thus these four dielectric bars are excited by externally applied electromagnetic waves. The four dielectric bars respectively cause the electric field to converge on the bars, and the single horn with four internally inserted dielectric bars acts as if it is partitioned into four horns.

Abstract: An antenna suited for receiving/transmitting electromagnetic signals from/to at least two satellites, which are fixedly placed at points on the geostationary path, is waveguide or lens type, formed by a multitude of waveguiding channels, which for example can be rotationally symmetrically arranged about an axis. Signals from remote points, which arrive in directions somewhat deviating from the direction of the axis, e.g. in an angle &agr;in thereto, exit after being refracted in the antenna in a different direction, so that the angle &agr;ut on the exit side differs from the angle &agr;in on the entrance side. It is achieved by having all of the waveguiding channels form suitably adapted angles to the axis. For a concave antenna it can give an increased separation between the positions, to which signals from remote objects are refracted by the antenna. It results in, for example, large more efficient receiver horns being used for the same size of the antenna.

Abstract: A horn antenna for transmitting microwaves. A conical horn includes a small opening and a large opening. A transition piece includes a tapering portion and a non-tapering portion. The transition piece is arranged in the conical horn between a waveguide and an environment that the horn antenna is arranged in. A transition between the tapering portion and the non-tapering portion is arranged between the small opening and the large opening of the conical horn. The non-tapering portion engages the small opening of the conical horn.

Abstract: A parabolic horn antenna designed for use as a high isolation antenna array in a wireless Internet access system where a high concentration of transceivers at one location is required. The rear, reflecting surface of the horn part of the antenna is a parabolic shape with the probe located at the focal point of the parabola. The sides of the antenna in the broad dimension are angled at an optimum degree increasing the opening aperture allowing the system to capture more RF energy. The length, therefore the aperture width is variable providing control over the gain of the system thus providing effective shielding and isolation for more dense antenna arrays.

Abstract: A photonics sensor and array for the reception and processing of RF signals. In one embodiment, the present invention is an antenna comprising: a first electro-optically active optical waveguide; a first planar electrode substantially parallel to the first waveguide; a second electro-optically active optical waveguide; a second planar electrode substantially parallel to the second waveguide, the first and second planar electrodes being substantially adjacent and coplanar; and a third planar electrode substantially parallel to the first and second planar electrodes and disposed such that the first waveguide lies between the first and third planar electrodes, and the second waveguide lies between the second and third planar electrodes.

Abstract: An antenna for providing a first antenna pattern at a first frequency of operation and a second antenna pattern at a second frequency of operation from first and second RF signals, respectively. The antenna included a horn which is dimensioned to generate the first antenna pattern from the first RF signal. A conduit is located within the horn and is configured to propagate the second RF signal in a waveguide mode. A corrugated rod having a first and a second portion is associated with the conduit. The first portion of the rod is located inside the conduit and the second portion of the rod protrudes from the conduit into the horn. The rod is configured to be responsive to the second RF signal and is operative to transition the second RF signal from a waveguide mode to a surface wave mode and propagate the second RF signal in a surface wave mode along the rod. The rod is configured to generate a second antenna from the second RF signal propagating in a surface wave mode.

Abstract: An antenna based on the resonance phenomena of a fast-wave leaky mode is small in size, can be installed in a printed circuit board by using surface mounting technology, and can use dielectric materials with a relative permittivity of between 2 and 5.

Abstract: The Microwave Hematoma Detector is a non-invasive device designed to detect and localize blood pooling and clots near the outer surface of the body. While being geared towards finding sub-dural and epi-dural hematomas, the device can be used to detect blood pooling anywhere near the surface of the body. Modified versions of the device can also detect pneumothorax, organ hemorrhage, atherosclerotic plaque in the carotid arteries, evaluate perfusion (blood flow) at or near the body surface, body tissue damage at or near the surface (especially for burn assessment) and be used in a number of NDE applications. The device is based on low power pulsed microwave technology combined with a specialized antenna, signal processing/recognition algorithms and a disposable cap worn by the patient which will facilitate accurate mapping of the brain and proper function of the instrument.

Abstract: A horn antenna is provided which is capable of operating at a plurality of separate frequencies while providing substantially equalized E and H-plane patterns for each of the separate frequencies. The antenna includes a coupling portion to permit coupling to a communication device. An inner portion is coupled to the coupling portion, and includes a first choke having a depth which extends substantially parallel to a central longitudinal axis of the antenna and a width which extends in a radial direction of the antenna. The depth and the width of the first choke are set so that the first choke will operate at the first frequency. An outer portion is coupled to the inner portion, wherein the outer portion has a maximum diameter in the radial direction which is greater than the maximum diameter in the radial direction of the inner portion.

Abstract: An antenna feed horn (10) for a satellite antenna array that includes multiple chokes (34, 36, 40, 42, 44) that provide effective control of the horn aperture mode content to generate radiation patterns which substantially have equal E-plane and H-plane beamwidths, low cross-polarization, low axial ratio, and suppressed sidelobes. The chokes (34, 36, 40, 42, 44) are annular notches that have both radial and axial dimensions. Two chokes (34, 36) are provided at an internal transition location between a conical profile section (14) and a cylindrical aperture section (16). Additionally, another choke (44) is provided in the aperture (20) of the horn (10), and two additional chokes (40, 42) are provided proximate the aperture (20).

Abstract: An electronically scanned antenna that is manufactured using semiconductor material and device fabrication technology. The antenna has a semiconductor substrate having a plurality of stubs projecting from one surface. The semiconductor substrate may be silicon, gallium arsenide, or indium phosphide, for example. A first conductive layer formed on the surfaces of the semiconductor substrate and along sides of the stubs so that the stubs are open at their terminus. The conductive layers form a parallel plate waveguide region. A diode array having a plurality of diode elements is formed in the semiconductor substrate that are disposed transversely across the semiconductor substrate and longitudinally down the semiconductor substrate between selected ones of the plurality of stubs. The diode array may comprise an array of Schottky or varactor diodes, for example.

Abstract: A device includes a waveguide for the transmission/reception of microwave signals. The waveguide is coupled to a microstrip reception circuit as well as to a microstrip transmission circuit. The waveguide includes a filter arrangement which attenuates the microwave signals transmitted from the transmission circuit in order to prevent undesirable interference to the reception circuit.

Abstract: For use in or with a satellite receiving system having a receiving element such as low noise amplifier, a selectively variable RF signal attenuator locatable between the satellite and the amplifier comprises an RF radiation shield having at least one selectively variable radiation-passing area. The radiation shield comprises a plurality of overlapped shield members having selectively overlapped openings, movement of one member relative to the other causing the effective intersection defining a radiation-passing area of the shield to vary. According to a disclosed method, after locating a radiation attenuator as described between the satellite and the amplifier, the signal received from the satellite is variably attenuated using the signal attenuator until the signal level of the received radiation is within a range of an associated signal indicator wherein the indicator's response is more linear than it is at higher signal levels.

Abstract: A polarizer for exciting the parabolic reflector of a directional antenna includes a profile section (7) which is formed as a waveguide and is adapted to simultaneously transmit two linearly polarized orthogonal electromagnetic waves. Two rectangular waveguides which separately guide the two electromagnetic waves are connected to the profile section (7). The end face of one of the rectangular waveguides is connected to the side wall of the profile section (7) in a radial direction, whereas the other rectangular waveguide is connected to an end face of the profile section (7). Both rectangular waveguides have an electromagnetic connection to the profile section (7) via openings, wherein a short-circuiting element (10) is disposed in the profile section (7) between the openings.

Abstract: An electronic device including a wave transmitter covering a determined spatial sensing field, and a wave receiver for controlling an automatic device; a radiating antenna including a waveguide having lateral faces and slots arranged on one of the lateral faces, wherein the slots radiate in planes substantially perpendicular to a longitudinal direction of the waveguide, and wherein the wave transmitter and the wave receiver are arranged at one end of the waveguide; a matched load arranged at an opposite end of the wave guide; substantially identical reflectors arranged over substantially the whole length of the waveguide, wherein the reflectors extend essentially symmetrically with respect to longitudinal plane of symmetry of the waveguide and making a predetermined angle with one another, and wherein the waveguide and the reflectors are composed of at least one piece.

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: A device is provided for fastening an excitation element (2) in a metal waveguide (3) of an antenna (1) and for electrically connecting the same to a coaxial line (4) arranged outside the waveguide (3), and which is cost effective and in which low power losses occur. The device comprises a basic member (6), which seals an opening in the waveguide (3), has a bore (6.1), and a metal hollow cylinder (9), through which an inner conductor of the coaxial line (9) is guided, which hollow cylinder has a first section (9.1) plugged into the first bore (6.1), and which has a second section (9.2), over which an end region (10) of an outer conductor of the coaxial line (4) is pushed. A first end (2.1) of the excitation element (2) is fastened on one end (12) of the inner conductor.

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 electronically scanned antenna that is manufactured using semiconductor material and device fabrication technology. The antenna has a semiconductor substrate having a plurality of stubs projecting from one surface. The semiconductor substrate may be silicon, gallium arsenide, or indium phosphide, for example. A first conductive layer formed on the surfaces of the semiconductor substrate and along sides of the stubs so that the stubs are open at their terminus. The conductive layers form a parallel plate waveguide region. A diode array having a plurality of diode elements is formed in the semiconductor substrate that are disposed transversely across the semiconductor substrate and longitudinally down the semiconductor substrate between selected ones of the plurality of stubs. The diode array may comprise an array of Schottky or varactor diodes, for example.

Abstract: There is provided a laminated aperture antenna in which a conductor wall composing the antenna is composed of a plurality of through conductors disposed at predetermined intervals and a plurality of sub-conductor layers disposed between dielectric layers of a dielectric substrate so as to electrically connect the plurality of through conductors within the dielectric substrate formed by laminating dielectric layers, or in which a resonant space is formed by a space of the dielectric surrounded by the conductor wall composing the antenna formed as described above, a lower conductor layer electrically connected to that and an aperture of the upper conductor layer corresponding to the antenna conductor wall. There is also provided a multi-layered wiring board comprising such laminated aperture antenna. Such laminated aperture antenna may be miniaturized and thinned and may be readily fabricated by the conventional lamination technology.

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

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

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

Abstract: An inverted boxhorn antenna array comprising a power divider that is constructed from a single metal piece and a flat metal sheet that is fastened to a rear surface of the power divider. The power divider is fabricated using a variety of waveguide junctions coupled between substantially identical inverted boxhorn subarrays. The junctions includes a central magic tee junction for coupling energy from an input port into the power divider. Alternating folded shunt and folded series tee junctions are used to transfer power coupled by way of the central series junction to the inverted boxhorn subarrays. Specially dimensioned folded shunt and series tee junctions are used in the inverted boxhorn subarrays. Waveguide matched loads are bonded in waveguides between each of the inverted boxhorn radiators of the subarrays. A fully functional antenna assembly includes a radome cover, a quadrature correction plate 18a, and a twist polarizer disposed in front of radiating elements of the inverted boxhorn antenna array.

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

Abstract: A 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 planar antenna radiating structure comprising an array of continuous transverse stubs having a stepped configuration arranged in a ground plane of a parallel-plate waveguide. Control of the complex reflection coefficient of the aperture of the radiating structure over a range of operating frequencies and scan angles is accomplished using parallel-plate waveguide modes through a choice of stub length(s), stub height(s), inter-stub spacings, parallel-plate separation and the properties of dielectric media used for the parallel-plate waveguide and stubs.

Abstract: Microwave tumor detection apparatus includes a probe having a working end arranged to contact tissue. Positioned in the probe is at least one rectangular waveguide each waveguide having an aperture at the working end of the probe. The waveguides constitute antennas tuned to receive microwave radiation emitted by the tissue opposite the working end of the probe. Each waveguide is coupled electrically and mechanically to a dedicated radiometer in the probe for detecting the temperature of tissue opposite that waveguide. These radiometers have thermally conductive casings which are mounted to a common heat sink and are insulated so that all of the radiometers have a uniform thermal distribution. Also, a thin thermally insulating interface pad may be located between the working end of the probe and the tissue contacted by the probe to prevent such contact from causing changes in the surface temperature of the tissue. A method of detecting breast tumors is also disclosed.

Abstract: A phased array antenna including a number of waveguide radiators in a power supply system. A calibration network provides a test pulse. By directly connecting the calibration network to the waveguide radiators, a more accurate calibration is obtained due to the processing of any phase and amplitude errors arising in the waveguide radiators in a calibration algorithm. The calibration network can be designed as a system of waveguides.

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

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

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

Abstract: A feed assembly waveguide interface (10) between an antenna (12) coupled onto an upright post (14) and an outdoor radio (16), comprising a feed tube (18) connected at a first end (20) to a sub-reflector (22) and a second end (24) having a waveguide output (26). A structure (28) is for affixing the feed tube (18) internally within the antenna (12), so that the second end (24) will extend outwardly from a rear wall (30) of the antenna (12). An assembly (32) for spring loading the feed tube (18) on the affixing structure (28) will allow the second end (24) to be forced outwardly away from the rear wall (30) of the antenna (12). When the outdoor radio (16) is mounted to the rear wall (30) of the antenna (12), a positive interface connection will be made between the outdoor radio (16) and the antenna (12), thus making a solid mechanical connection between the outdoor radio (16) and the antenna (12), as well as a proper electrical and environmental seal.